Import from cleaned 360 CD

.gitattributes

+hdr/** gitlab-language=armasm linguist-language=armasm linguist-detectable=true
+s/** gitlab-language=armasm linguist-language=armasm linguist-detectable=true

Doc/!Bits

+
+Bit settings for CDFSDriver: (bit numbering starts from 0, ie/ bit 0 = 1, bit 3 = 8 etc; )
+
+Description                Bit number      Command      Length of CDB
+---------------------------------------------------------------------
+    SCSI_READ                6              &28            10
+    SCSI_SEEK                7              &2b            10
+    SCSI_INQUIRY             8              &12             6
+    SCSI_CAPACITY/DISCUSED   9              &25            10
+    SCSI_READY              10              &00             6
+    SCSI_STOPOPEN           11              &1b             6
+    SCSI_CHECK              12              &1d             6
+    SCSI_STATUS             13              &00             6
+    SCSI_CONTROL            14              ---            --   this calls SWI SCSI_Control
+    SCSI_PREFETCH           15              &28            10   see SCSI_READ
+    SCSI_RESET              16              ---            --   this calls SWI SCSI_Initialise

Doc/!Changes

+
+ CDFSDriver history:
+
+;-----------------------------------------------------------------------------------------------
+2.15   01-Mar-93   MEW Eesox   Totally rewritten to allow soft-loadable driver support
+;-----------------------------------------------------------------------------------------------
+2.16   24-Jun-93   MEW Eesox   Bug fix: problem with more than one drive type - it didn't
+                               send the discchanged command to the correct driver !
+;-----------------------------------------------------------------------------------------------
+2.21   05-Jul-94   MEW Eesox   CD_ReadAudio added
+;-----------------------------------------------------------------------------------------------
+2.30   19-Jul-94   MEW Eesox   CD_ReadUserData added.  'buffer' extended from 256 to 2340 bytes
+;-----------------------------------------------------------------------------------------------
+2.30a  19-Sep-94   MEW Eesox   Bug fix - removed check to see if soft-load driver can support
+                               the SWI.
+;-----------------------------------------------------------------------------------------------
+2.31   25-Jan-95   MEW Eesox   Added support for CD_GetAudioParms and CD_SetAudioParms
+;-----------------------------------------------------------------------------------------------

Doc/DevKit/CDSWIs

+; CD_Routine Headers
+
+
+; This contains details of entry and exit conditions for the general routines that all 
+; soft drivers may use
+
+
+; Routines defined:
+;
+;                  cd_checkdrive
+;                  cd_control
+;                  cd_converttolba
+;                  cd_converttomsf
+;                  cd_discused
+;                  cd_driveready
+;                  cd_drivestatus
+;                  cd_inquiry
+;                  cd_lasterror
+;                  cd_opendrawer
+;                  cd_prefetch
+;                  cd_readdata
+;                  cd_reset
+;                  cd_seekto
+;                  cd_stopdisc
+;                  cd_version
+;                  cd_identify
+;                  cd_register
+;                  cd_unregister
+
+
+;-----------------------------------------------------------------------------------------------
+cd_version 
+;
+; on entry:
+;          nothing needed
+; on exit:
+;          r0 -> version string ( word 0 = version number * 100, word 1 .. = null term. string )
+;
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_lasterror 
+;
+; on entry:
+;          nothing needed
+; on exit:
+;          r0 = number of last error, or 0 if none
+;
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_prefetch  
+;
+; on entry:
+;          r0 =   addressing mode
+;          r1 =   block number
+;          r7 ->  control block
+; on exit:
+;          if error then r0-> error block, else all regs preserved
+;
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_readdata     **** check this with Mark ****
+;
+; on entry:
+;          r0 =   addressing mode
+;          r1 =   block number
+;          r2 =   number of blocks
+;          r3 ->  where to put data
+;          r4 =   number of bytes from each block wanted
+;          r7 ->  control block
+;          r12 -> any workspace required
+;          r13 -> full descending stack
+; on exit:
+;          if error then r0-> error block, else all regs preserved
+;
+
+; r8  = scsi device id
+; r9  = card number
+; r10 = lun
+;-----------------------------------------------------------------------------------------------
+
+
+;-----------------------------------------------------------------------------------------------
+cd_seekto  
+;
+; on entry:
+;          r0 =   addressing mode
+;          r1 =   block number
+; on exit:
+;          if error then r0-> error block, else all regs preserved
+;
+;-----------------------------------------------------------------------------------------------
+
+
+;-----------------------------------------------------------------------------------------------
+cd_inquiry  
+;
+; on entry:
+;          r0 -> place to put the inquiry data
+;          r7 -> control block
+; on exit:
+; 
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_discused  
+;
+; on entry:
+;          r0 =  addressing mode that the disc length should be returned in
+;          r1 -> storage area to put data in
+;          r7 -> control block
+; on exit:
+;
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_driveready  
+;
+; on entry:
+;          r7 -> control block
+; on exit:
+;          r0 = 0 if drive is OK, else r0 = 1
+;
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_stopdisc  
+;
+; on entry:
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_opendrawer  
+;
+; on entry:
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_converttolba  
+; on entry:
+;          r0 = address mode
+;          r1 = address
+; on exit:
+;          if oVerflow set then r0 -> error block
+;          r1 = new address
+;
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_converttomsf  
+; on entry:
+;          r0 = address mode
+;          r1 = address
+; on exit:
+;          if oVerflow set then r0 -> error block
+;          r1 = new address
+;
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_drivestatus  
+;
+; on entry:
+;          r7 -> control block
+; on exit:
+;          r0 = status { 1=OK, 2=BUSY, 4=NOTREADY, 8=UNAVAILABLE }
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_control  
+;
+; on entry:
+;          r0 = 0, 1 or 2 to set the level of error response
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_reset  
+;
+; on entry:
+;          r7 ->  control block
+; on exit:
+;          if error then r0-> error block, else all regs preserved
+;
+;-----------------------------------------------------------------------------------------------
+
+;-----------------------------------------------------------------------------------------------
+cd_checkdrive  
+;
+; on entry:
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;          r0 = drive status bits
+;-----------------------------------------------------------------------------------------------
+
+;----------------------------------------------------------------------------------------------
+cd_identify
+;
+; on entry:
+;          r7 -> control block
+;                control block + 0  = SCSI device id
+;                control block + 4  = SCSI card number
+;                control block + 8  = Logical unit number
+;                control block + 12 = 0 - drive type not needed
+; on exit:
+;          if oVerflow clear:
+;                r0 - r1 preserved
+;                r2 = drive type given by CDFS driver, else -1 if type not recognized
+;          if oVerflow set:
+;                r0 -> error block, could be because no drivers loaded
+;                r1 - r9 preserved
+;
+;----------------------------------------------------------------------------------------------
+
+; the 'buffer' in workspace is to be used as follows:
+; bytes 0  to  7 are to build the inquiry command up
+; bytes 8  to 44 are for the returned inquiry data
+
+;--------------------------------------------------------------------------------------------
+
+;----------------------------------------------------------------------------------------------
+cd_register 
+;
+; on entry:
+;           r0 -> block
+;                 block + 0 = information word for CDFSDriver module
+;                 block + 4 = number of times registered (should be set to zero
+;                             and will be updated by CDFSDriver)
+;                 block + 8 = number of drive types recognized by this driver
+;           r1 -> special tag (&EE50EE50 = 1 word) followed by the handler code
+;           r2 -> workspace for soft-loadable module (this will be R12 in the handler)
+;
+;           r12 -> my workspace pointer
+; on exit:
+;          Overflow flag clear if registered OK, else set and R0->error block.
+;
+;----------------------------------------------------------------------------------------------
+
+;----------------------------------------------------------------------------------------------
+cd_unregister
+;
+; on entry:
+;           r0 -> block
+;                 block + 0 = information word for CDFSDriver module
+;                 block + 4 = number of times registered (should be set to zero
+;                             and will be updated by CDFSDriver)
+;                 block + 8 = number of drive types recognized by this driver
+;           r1 -> special tag (&EE50EE50 = 1 word) followed by the handler code
+;
+;           r12 -> my workspace pointer
+; on exit:
+;          Overflow flag clear if registered OK, else set and R0->error block.
+;
+;----------------------------------------------------------------------------------------------
+
+; r8 = registered count
+
+;----------------------------------------------------------------------------------------------

Doc/DevKit/Example

+ REM -----------------------------------------------------------------------------------------------
+ REM >CDDemo
+ REM     Provides basic details of how to use CD SWIs
+ REM     Copyright Acorn Computers, 1994
+ REM
+ REM     This code should be used in conjunction with the CDFS SWIs Application Note
+ REM     available from Acorn Developer Support.
+ REM
+ REM     For further details contact:
+ REM                                 Technical Support
+ REM                                 Acorn Computers Ltd
+ REM                                 Acorn House
+ REM                                 Vision Park
+ REM                                 Histon
+ REM                                 Cambs CB4 4AE
+ REM
+ REM                                 Tel: +44 223 254254
+ REM -----------------------------------------------------------------------------------------------
+
+ DriveNumber% = 0                                        : REM 0 = first, 1 = second etc
+
+ END = &8000000
+
+ DIM ControlBlock 30
+
+ REM -----------------------------------------------------------------------------------------------
+ REM Initialise the Control Block for subsequent CDFS access
+ REM -----------------------------------------------------------------------------------------------
+
+ PROCInitControlBlock(DriveNumber%)
+
+ REM -----------------------------------------------------------------------------------------------
+ REM User code can be placed after this point eg,.......
+ REM -----------------------------------------------------------------------------------------------
+
+
+ REM -----------------------------------------------------------------------------------------------
+ REM Check the drive status  1=OK, 2=BUSY, 4=NOT READY, 5=UNAVAILABLE
+ REM -----------------------------------------------------------------------------------------------
+
+ SYS "CD_DriveStatus",,,,,,,,ControlBlock TO stat%
+
+ REM -----------------------------------------------------------------------------------------------
+ REM Eject the disc if the drive status is OK, otherwise print an error message
+ REM -----------------------------------------------------------------------------------------------
+
+ IF stat% = 1 THEN
+    SYS "CD_OpenDrawer",,,,,,,,ControlBlock
+ ELSE
+    PRINT "Drive status error : ", stat%
+ ENDIF
+
+ END
+
+
+
+ REM -----------------------------------------------------------------------------------------------
+ REM  InitControlBlock(drive%)
+ REM
+ REM     This routine calls the ConvertDriveToDevice SWI, then sets up
+ REM     ControlBlock (defined globally) with the necesary data for further
+ REM     CDFS calls
+ REM -----------------------------------------------------------------------------------------------
+
+
+ DEFPROCInitControlBlock(drive%)
+   LOCAL device%, a
+
+   SYS "CDFS_ConvertDriveToDevice", drive% TO a,device%
+
+   ControlBlock!0  = (device% AND &00000007)
+   ControlBlock!4  = ((device% >> 3) AND &00000003)
+   ControlBlock!8  = ((device% >> 5) AND &00000007)
+   ControlBlock!12 = ((device% >> 8) AND &000000FF)
+   ControlBlock!16 = ((device% >> 16) AND &0000FFFF)
+
+ ENDPROC
+

Doc/DevKit/UG_Text

+****************************************************************************
+******************* THE CD-ROM FILING SYSTEM USER GUIDE ********************
+****************************************************************************
+
+Copyright © 1990, 1991 Next Technology Corporation Limited. All rights reserved.
+Copyright © 1993 Acorn Computers Limited. All rights reserved.
+Issue 3, October 1993
+
+                      
+                      The CD-ROM Filing System User Guide
+                      ===================================
+
+
+The product described in this manual is subject to continuous development 
+and improvement. All information of a technical nature and particulars of 
+the product and its use (including the information and particulars in this 
+manual) are given by Acorn Computers Limited in good faith. However, 
+Acorn Computers Limited cannot accept any liability for any loss or damage 
+arising from the use of any information or particulars in this manual.
+ACORN, the ACORN logo and ARCHIMEDES are trademarks of Acorn 
+Computers Limited.
+All other trademarks are acknowledged.
+Copyright © 1990, 1991 Next Technology Corporation Limited. All rights 
+reserved. Copyright © 1993 Acorn Computers Limited. All rights reserved.
+Published by Acorn Computers Limited
+
+
+
+Configuring the computer
+________________________
+
+The CD-ROM Filing System (CDFS) enables you to access data on a 
+CD-ROM from the RISC OS desktop. It is usually resident in a ROM 
+on your SCSI expansion card, and is loaded automatically when you 
+power on your computer. The CDFS icon bar menu enables you to 
+configure your computer to suit the CD-ROM system attached to it.
+
+This section tells you how to configure your computer so that you 
+can use CD-ROMs; you only need to do so when adding or removing 
+drives.
+
+For details of how to use CDFS once you have configured it, see 
+Using CD-ROM discs on page 7.
+
+Configuring your RISC OS computer from the desktop
+
+To ensure the fastest boot up time, the following procedure should 
+be followed:
+
+1 Ensure all the peripherals and cables are connected.
+
+2 Switch on the monitor, then the CD-ROM drive. The CD-ROM 
+drive should always be switched on before the computer.
+
+3 Switch on the computer. CDFS will look to see if a CD-ROM 
+drive is connected.
+
+4 The CDFS CD-ROM icon will be displayed on the Icon Bar.
+
+Click on this icon to determine which type of CD-ROM is 
+currently held in the drive drawer - CD-ROM, Photo CD or 
+Audio CD.
+
+5 To configure the number of CD-ROM drives you have attached 
+to your computer, click Menu on the CD-ROM icon. The CDFS 
+icon bar menu will be displayed:
+
+6 Choose Configure, Drives then enter the number of drives 
+connected. If only one drive is connected, this step may be left 
+out, but the boot-up time will be slower:
+
+7 To configure the CD-ROM buffers, click Menu on the CD-ROM 
+icon. Choose Configure, Buffers then click on the required 
+buffer size - 16K is normally sufficient, unless you are swapping 
+discs a lot, in which case 32K or 64K would be better:
+
+8 Reset the computer to implement the new configuration.
+
+Setting up PC Soft to read CD-ROM discs
+
+Many CD-ROM titles are written in PC format, so to get the best out 
+of these, PC Soft should be used in the computer. (PC Soft used to 
+be known as the Acorn PC Emulator.) The copy of PC Soft you use 
+must be version 1.6 or later.
+
+If you are using MS-DOS, you must have version 3.3 or higher, with 
+CD-ROM extensions.
+
+If you are using DR-DOS, you must have a version with CD-ROM 
+extensions. At the time of going to press, such versions were not yet 
+available - but this is likely to change. You should see your supplier 
+for details of DR-DOS compatibility, availability, and installation.
+
+Loading PC Soft
+
+Load PC Soft as instructed in the PC Soft Guide accompanying it. 
+
+Set the configuration of the emulated PC, using the Configure 
+option from the PC icon bar menu. Choose EGA and ECD for titles 
+using this screen mode, with 128K of memory for computers with 
+2MB of RAM, and 256K for those with more RAM. Choose VGA for 
+titles using this screen mode. (Versions 1.6 and 1.7 do not support 
+VGA, but you can choose EGA+ for a partial emulation of VGA 
+mode.)
+
+By default, the CD-ROM drive will be configured as drive F. 
+Additional drives will be named G, H and so on. However, if you 
+have four hard disc drives configured (drives C-F) then the CD-ROM 
+drive will install itself as drive G, and additional drives follow on 
+from there.
+
+Now run PC Soft. Switch to Single task mode (from the icon bar 
+menu) to be able to display a full screen, and for faster response.
+
+Loading the MS-DOS CD-ROM support software
+
+PC Soft (version 1.6 or later) when sold with MS-DOS is 
+accompanied by a CD-ROM Support disc. The software on this disc 
+enables you to access the CD-ROM drive while you are running 
+DOS. 
+
+The software has its own installation program, to make it easy for 
+you to install it on your computer. This program alters your DOS 
+AUTOEXEC.BAT and CONFIG.SYS files and copies Microsoft 
+MS-DOS CD-ROM extensions and the CD-ROM device driver.
+
+If you usually boot DOS from a floppy disc, you first need to format 
+a new system floppy disc on which to install the software. To do this, 
+put a floppy disc in the drive and type:
+
+FORMAT A: /S
+
+When the format completes, remove this disc from the drive.
+
+To install the software, put the disc labelled CD-ROM Support disc 
+into the drive. Type:
+
+A:
+INSTALL
+
+This starts the installation program. Follow the instructions given 
+on the screen.
+
+When prompted for a drive letter on which to install this software:
+
+* If you boot DOS from a floppy disc, type A. When the 
+installation program prompts for your boot disc, insert the 
+newly-formatted system disc, and press Space. When you are 
+prompted to insert the disc containing MSCDEX.EXE, put the 
+CD-ROM Support disc back in the drive.
+
+* If you boot DOS from a hard disc, type the hard disc drive letter 
+(typically C).
+
+When the installation program has finished, reboot DOS from your 
+hard disc, if you have one, or else put your newly-created system 
+disc back in the drive and hold down Ctrl and Alt and press Delete 
+to do this. 
+
+During the reboot cycle a message should be displayed on the 
+screen similar to the following:
+
+MSCDEX Version 2.20
+Copyright ) Microsoft Corp. 1986
+Drive F: = Driver CDFSEM unit 0
+
+This indicates that the driver is loaded and the CD-ROM drive has 
+been allocated the letter F: for access purposes from DOS.
+
+Your computer will now behave like a PC with a CD-ROM drive 
+attached. There is a summary of common PC commands in the 
+PC Soft Guide.
+
+Recommended changes to configuration files
+
+We recommend that you check that the following statements exist 
+in the CONFIG.SYS and AUTOEXEC.BAT files and amend or add 
+them as necessary as some DOS formatted CD-ROM discs require 
+these settings before they can be used.
+
+In the CONFIG.SYS file we recommend you add these lines:
+
+FILES=20
+BUFFERS=20
+
+In the AUTOEXEC.BAT file your PATH should include the 
+pathnames below, in the order given:
+
+PATH=C:\;C:\DOS;F:\    (Hard drive users.)
+PATH=A:\;A:\DOS;F:\    (Floppy drive users.)
+
+Of course, your PATH may also include other pathnames you have 
+previously added.
+
+
+Using CD-ROM discs
+__________________
+
+You can use CD-ROM drives either with CD-ROM discs formatted for 
+use with RISC OS, or with CD-ROM discs produced to run under 
+MS-DOS. For the latter, you will need a copy of PC Soft to get full 
+benefit.
+
+Using CDFS
+
+CDFS appears to the user very much like ADFS - all the usual 
+RISC OS Filer commands are available, although you cannot of 
+course save to a CD-ROM. If a write command is made to the 
+CD-ROM drive, an error message will be displayed. 
+
+To open a directory display on a CD-ROM which has been inserted 
+in the drive, click on the CD-ROM drive icon on the icon bar. The 
+contents of the CD-ROM will be displayed by the RISC OS Filer:
+
+RISC OS directory displays can be opened for PC CD-ROMs. PC file 
+names are translated to a format compatible with the RISC OS 
+environment. You can view text files using Edit in the same way as 
+usual, and use ChangeFSI (see page 15) to convert a wide range of 
+graphics images to RISC OS sprites, which you can then view using 
+Paint. However, to run the programs included on such discs, you will 
+need to use PC Soft (see Reading PC-format CD-ROM discs using PC Soft 
+below).
+
+If you are not using CDFS
+
+CDFS claims some memory each time you power on your computer. 
+If you are not using CDFS and need this extra memory, you can 
+disable CDFS by typing
+
+*Unplug CDFS
+*Unplug CDFSDriver
+*Unplug CDFSFiler
+
+and then resetting your computer. When you need CDFS again, you 
+can reinstall the three modules by using *RMReInit for each one 
+in a similar way, and then rebooting.
+
+Reading PC-format CD-ROM discs using PC Soft
+
+Place a CD-ROM disc in the drive, and type 
+
+F:
+
+(or whatever drive letter your CD-ROM drive is configured as).
+
+You can now access PC-format discs in the normal way. 
+
+Consult the guide that comes with each title for information on 
+playing CD-ROM discs.
+
+Do not try to access a CD-ROM through RISC OS (including via 
+CDPlayer) and through PC Soft at the same time.
+
+Performance limitations
+
+VGA images
+
+Version 1.6 and 1.7 of the Acorn PC Emulator (the old name for 
+PC Soft) do not fully support the VGA Bios. EGA+ is a partial 
+implementation of VGA, but some VGA images on PC format 
+CD-ROM discs cannot be displayed fully. The title screens of some 
+discs are designed to be displayed in VGA mode, so such discs may 
+not start off very well. This does not, however, necessarily mean that 
+the rest of the disc cannot be read correctly. Often the application 
+will continue of its own accord, or require Space or Return to be 
+pressed. In some cases the lack of VGA support will prevent the disc 
+from running under the emulator at all.
+
+Version 1.8 of PC Soft does support VGA.
+
+Sound
+
+Titles which attempt to play sound through the computer's own 
+sound system can cause program errors, unless you first configure 
+sound in the program to be off. Most titles are able to play 
+CD-quality sound through a CD-ROM drive, so this problem does 
+not often arise.
+
+Titles which attempt to mute one audio channel (left or right), 
+whilst playing the other channel, can cause program errors.
+
+Windows 
+
+Certain CD-ROM applications contain their own version of 
+Windows on the CD-ROM itself. These versions have often been 
+modified in some way, and do not always work correctly. We 
+recommend that you do not use a version of Windows supplied on 
+CD-ROM, but an appropriate Windows application available 
+separately from a PC dealer. 
+
+Note that Windows 3.1 will not run under PC Soft.
+
+
+CDPlayer
+________
+
+The CDPlayer application allows you to play and control audio CDs 
+using your computer and a CD-ROM drive. CDPlayer simulates all 
+the functions of a CD audio player with all the normal functions 
+such as play, stop, track search, cue and review. It also has a very 
+comprehensive programming facility. All the functions, including 
+drive select, are controlled using the mouse. 
+
+CDPlayer is supplied on floppy disc. It is already set up to use a 
+CD-ROM drive that has a SCSI ID of 6, and that is connected to the 
+first SCSI expansion card fitted to your computer. If you wish to use 
+a drive with a different SCSI ID, or if you have fitted multiple SCSI 
+expansion cards to your computer, you should first read The Setup 
+window on page 14.
+
+To start the application, double-click on the CDPlayer icon; this 
+loads the program and displays its icon on the icon bar. Click on its 
+icon to display the main CD Player window, used to control the CD:
+
+The main CD Player window
+
+The basic set of controls work in the same way as those of a 
+conventional audio CD player.
+
+Play starts the audio CD playing.
+
+Pause stops the CD playing, but holds it in its current position.
+
+Stop stops the CD playing, and returns to the start of the CD.
+
+Eject stops the CD and ejects it from the CD player.
+
+Skip backwards and Skip forwards move to the previous or next 
+tracks respectively.
+
+Rewind and Fast forward move backwards or forwards through the 
+audio track, speeding up as you hold down the button.
+
+Moving the Slider takes you quickly to any point on the CD.
+
+Track number shows the number of the track currently playing, or 
+(as above) 00 if nothing is playing.
+
+Playing time gives you three choices of display. It normally shows 
+the time the disc has been playing. Clicking on this number changes 
+the display to show the time the individual track has been playing; 
+clicking again shows the time left on the disc; clicking again returns 
+to the original display.
+
+Total tracks/time gives the total number of tracks on the CD, and 
+its total playing time.
+
+Display keypad displays the keypad, the use of which is described 
+in the next section.
+
+The Keypad window
+
+Clicking on the triangle icon or choosing Keypad from the 
+CD Player menu will open the Keypad window. You can use this 
+window to select which tracks on the CD you wish to hear and in 
+which order you wish to hear them:
+
+To program the player to play a selection of tracks
+
+1 Click on the first track number you wish to hear, and then on 
+MEM. The Memory window automatically appears, showing the 
+tracks in the program memory:
+
+2 Repeat this for any other tracks you wish to add to the program 
+memory.
+
+3 Play the tracks by clicking on Play.
+
+Other program play functions
+
+ALL adds a list of all the audio tracks available on the CD to the 
+program memory.
+
+RND clears the program memory, and creates a randomly ordered 
+list of all the audio tracks to the program memory. 
+
+RPT continuously repeats the tracks in the program memory until 
+you click on the Stop key in the CD Player window. If no program has 
+been set, the CD instead repeats continuously from start to finish.
+
+CLR is used to clear the program memory. To clear all tracks from 
+the program memory, click Adjust on the CLR button. To clear 
+individual tracks, highlight the desired tracks and then click Select 
+on the CLR button.
+
+Notes on playing programs
+
+When CDPlayer is set to play a program, the following restrictions 
+apply:
+
+* The slider and slider bar cannot be dragged or clicked on.
+
+* The time display will only show the time the disc has been 
+playing.
+
+* The main CD Player window must be open to allow the 
+programmed tracks to be played.
+
+When playing a mixed mode CD (mixed audio and data tracks), 
+using the ALL button guarantees that all the audio tracks will be 
+played, otherwise the drive will normally stop when it encounters a 
+data track, even if there are subsequent audio tracks.
+
+The Setup window
+
+Each CDPlayer can be used to control a single CD-ROM drive at one 
+time, which is selected using the Setup window. CDPlayer is 
+supplied already set up to use a CD-ROM drive that has a SCSI ID 
+of 6, and that is connected to the first SCSI expansion card fitted to 
+your computer. You'll only need to change the Setup if you wish to 
+use a drive with a different SCSI ID, or if you have fitted multiple 
+SCSI expansion cards to your computer.
+
+To open the Setup window, choose Setup from CDPlayer's icon bar 
+menu:
+
+Click on the + and - icons until the correct device, unit and card 
+numbers are shown for the CD-ROM drive you wish to use. If you're 
+not sure what the numbers should be for a particular drive, you can 
+find them out by typing at the command line:
+
+CDFS:CDDevices    (see page 22).
+
+It is not advisable to keep switching CDPlayer from one drive to 
+another using the Setup window. This operation should only be 
+performed when CDPlayer is first started. If you need to control 
+more than one drive, you should start the CDPlayer application as 
+many times as you require and change each copy's setup 
+individually before use.
+
+Quitting CDPlayer
+
+To quit the CDPlayer application, choose Quit from its icon bar 
+menu.
+
+
+ChangeFSI
+_________
+
+ChangeFSI is a useful program for converting and displaying image 
+files of various formats. These images can then be converted into 
+sprites for viewing with RISC OS applications such as Paint.
+
+In case you're wondering, ChangeFSI stands for `Change Floyd 
+Steinberg Integer' (ChangeFSI performs Floyd Steinberg error 
+diffusion dithering). 
+
+You should make sure that your conversion and subsequent use of 
+an image does not infringe on any copyright that the image may be 
+under.
+
+ChangeFSI provides the ability to read, scale the data to improve 
+the picture, change the x and/or y size, sharpen the picture and write 
+the result using error diffusion dithering in one step (so it provides 
+the best possible quality). All operations are carried out with 32-bit 
+fixed point numbers (three per pixel in the case of a colour picture).
+
+Using ChangeFSI
+
+ChangeFSI is supplied on floppy disc. Before using the application, 
+you should copy it either to another floppy disc, or to your 
+computer's hard disc - if one is fitted.
+
+Double click on the application to start ChangeFSI. Its icon will be 
+loaded onto the icon bar. Display the file icon for the image you 
+wish to process, and drag the icon onto the ChangeFSI application 
+on the icon bar. ChangeFSI will attempt to interpret the file to give a 
+RISC OS sprite, displaying the result. You can then save the 
+resultant image as a sprite file.
+
+Picture formats
+
+ChangeFSI will convert many types of images. These include the PC 
+graphics formats TIFF, PCX, PIC and IMG, the Amiga format IFF, the 
+Compuserv GIF format and the JPEG JFIF file interchange format.
+
+For a full list of image formats explained in greater detail, you 
+should read the file FSIInfo provided inside the application (shift 
+double-click on !ChangeFSI to display the files).
+
+ChangeFSI in more detail
+
+This section describes the ChangeFSI menu trees in detail. Most 
+users won't need to use these options as ChangeFSI is already set 
+up to give good results with most types of image files.
+
+If you want to know how ChangeFSI and its options are used in 
+greater detail you should read the information file, FSIInfo, provided 
+inside the application (shift double-click on !ChangeFSI to display 
+the files).
+
+Menu options
+
+Once you have loaded ChangeFSI onto the icon bar, click Menu over 
+the icon to display the main options menu.
+
+Scaling options
+
+The Scaling options allow you to choose which scale you wish for 
+your image. You can also transform, rotate or mirror the image.
+
+The option Scale 1:1 1:1 will give you a full sized image.
+
+Choosing Custom allows you to specify your own scaling options. If 
+you wish the image to `scale to exact pixel size', fill in the left boxes 
+only and leave the right boxes blank. The Scale to fill option allows 
+you to scale the image so that it covers the entire screen area; this 
+may distort the aspect ratio of the image.
+
+The Ignore Source Pixel Size box allows you to ignore any source 
+information about the pixel size. This can be useful if you have 
+images that use a non-standard pixel size.
+
+The Rotate and Mirror options perform rotations and mirror 
+operations on the source image.
+
+Processing options
+
+The Processing options allow you to control the image processing 
+used in the conversion and display of the image.
+
+You'll notice that all of these options are `off' by default; you will not 
+normally need to change these settings.
+
+Expand Dynamic Range will expand the range of colours in the 
+image. This normally brightens the image. It expands the dynamic 
+range of a picture to full scale.
+
+Histogram Equalisation will most often result in a worse picture 
+but it can be used to recover detail from an otherwise useless 
+image. Alternatively you can use it to look at information locked in a 
+small part of the input scale.
+
+Disable Dithering will disable Floyd-Steinberg dithering. This will 
+usually result in an inferior image.
+
+Invert Input will result in your colour images having their colours 
+inverted. Black and white image are also inverted.
+
+Brighten Picture will produce a picture that is slightly brighter than 
+it should be. Useful if you have dark pictures.
+
+Black Correction is useful if you want to print the image on a laser 
+printer. You should use a number between zero and 128, though 
+values between 32 and 64 usually give the best result; experiment. 
+Images treated in this way will give a poor result when viewed on 
+screen. Only works for 1 bpp (black and white) output.
+
+Gamma Correction is used to correct the image quality as 
+displayed on your monitor. Low values of gamma (0 to 1) make 
+colours darker and high values (above 1) make them lighter. Gamma 
+correction is most often used to correct images that have been 
+scanned in with a scanner. Different monitors may need different 
+Gamma Corrections. A standard value is 2.2 (TV industry standard).
+
+Pre-sharpening is used to sharpen the edges of objects. This is 
+useful if the dithering process has made the image blurred. A value 
+of 24 will counteract the general dither blurring. A value of 20 is 
+noticeably sharp. Values down to nine can be selected.
+
+Output options
+
+The Output options control the screen mode the picture is created 
+for.
+
+The 1, 2, 4, 8 buttons represent the screen colours that you can use. 
+The numbers represent bits per pixel. 8 bits represent 256 colours, 4 
+bits represent 16 colours, 2 bits represent 4 colours and 1 bit 
+represents 2 colours. The square box represents the square pixel 
+modes and the oblong box represents the non-square modes. The 
+actual output mode chosen is displayed in the mode box.
+
+Use current mode outputs the image for display in the current 
+mode.
+
+Ignore pixel aspect disables all pixel size information and assumes 
+both source and output pixels are square.
+
+Monochrome and Colour give an image in black and white or 
+colour.
+
+Special allows the use of special file suffixes. These are explained 
+fully in the on-line documentation file FSIInfo.
+
+Reprocess
+
+This option reads the file in again and processes it according to any 
+new options you have set.
+
+Fast 
+
+This option speeds up the processing of the image by blanking the 
+screen during processing.
+
+Save Choices
+
+This option will save any changes you have made to the ChangeFSI 
+options so that you can use the options again next time you run 
+ChangeFSI.
+
+Quit
+
+This quits the application, removing it from the icon bar.
+
+Image menu
+
+Once your image has been produced you can click Menu over the 
+image to display a menu of information about the input and output 
+image.
+
+Sprite Info gives the information about the Sprite output file.
+
+Source Info gives the information about the source file.
+
+Range Info gives you information about the dynamic range of the 
+image.
+
+Zoom allows you to change the magnification of the image. This is 
+not the same as scaling the source image.
+
+Save Sprite allows you to save the image as a Sprite file.
+
+Reprocess allows you to process the image again using any options 
+you have changed on the main menu.
+
+
+Using the command line
+______________________
+
+CDFS * Commands
+
+CDFS supports all standard RISC OS filing system * Commands that 
+do not try to write to disc; for details of these, see your RISC OS 3 
+User Guide. CDFS also provides some new commands of its own, 
+detailed below. Many of these commands require an optional drive 
+parameter; if you omit this, CDFS defaults to using its current drive 
+(initially drive 0).
+
+*CDDevices
+
+*CDDevices displays all the CD devices connected, their product 
+name, capacity, SCSI ID (displayed as device, LUN, and card) and 
+firmware revision.
+
+*CDDevices
+
+*CDFS
+
+*CDFS selects the CD-ROM filing system as the current filing 
+system.
+
+*CDFS
+
+*CDSpeed
+
+*CDSpeed displays or sets the read speed of the given CD-ROM 
+drive.
+
+*CDSpeed [drive] [speed]
+
+*Configure CDROMBuffers
+
+*Configure CDROMBuffers sets the configured amount of memory 
+reserved for CD-ROM buffering (maximum 512K).
+
+*Configure CDROMBuffers sizeK
+
+*Configure CDROMDrives
+
+*Configure CDROMDrives sets the configured number of CD-ROM 
+drives recognised at power on.
+
+*Configure CDROMDrives n
+
+*Eject
+
+*Eject ejects the disc from the given CD-ROM drive.
+
+*Eject [drive]
+
+*Lock
+
+*Lock locks the disc in the given CD-ROM drive, disabling the Eject 
+button.
+
+*Lock [drive]
+
+*Play
+
+*Play plays from the specified audio track to the end of the disc in 
+the given CD_ROM drive.
+
+*Play track [drive]
+
+*PlayList
+
+*PlayList lists the tracks - whether audio or data - on the disc in the 
+given CD-ROM drive, together with their start time and the total CD 
+time.
+
+*PlayList [drive]
+
+*PlayMSF
+
+*PlayMSF plays a piece of audio from the disc in the given CD-ROM 
+drive. The start and stop times are specified in minutes, seconds 
+and frames from the start of the disc.
+
+*PlayMSF mins:secs:frames mins:secs:frames [drive]
+
+*Stop
+
+*Stop stops playing the disc in the given CD-ROM drive.
+
+*Stop [drive]
+
+*Supported
+
+*Supported lists the drive types recognised by CDFS.
+
+*Supported
+
+*Unlock
+
+*Unlock re-enables the Eject button on the given CD-ROM drive, 
+reversing the effect of any earlier *Lock command.
+
+*Unlock [drive]
+
+*WhichDisc
+
+*WhichDisc displays the unique ID number for the current CD-ROM 
+drive.
+
+*WhichDisc
+
+Configuring CD-ROM drives from the command line
+
+To configure the number of CD-ROM drives, type:
+
+*Configure CDROMDrives n
+
+where n is the number of drives (from 0 to 28). You can set n to 0, 
+which obviously sets the configuration to 0 CD-ROM drives.
+
+You may want to configure the size of the CD-ROM buffers, 
+especially if you expect to be using a variety of CDs. Type:
+
+*Configure CDROMBuffers sizeK
+
+where size represents the size of the buffers in KB, a number in the 
+range 0-512.
+
+The configuration chosen will be stored in the CMOS RAM; reset the 
+computer to implement it. The computer should boot up into the 
+desktop. A `CD-ROM' icon should appear in the icon bar, the 
+number of icons representing the number of CD-ROM drives 
+attached.
+
+Important: Incorrectly setting the number of drives causes the boot 
+up procedure to take longer.
+
+Altering the default configuration of your system under 
+PC Soft
+
+The device driver
+
+The DOS device driver CDFS_DRV.SYS is configured by entering a 
+statement such as this in CONFIG.SYS:
+
+DEVICE = C:\DRIVERS\CDFS_DRV.SYS /D:MSCD001 /N:1
+
+Parameter switches are:
+
+Parameter
+
+Use
+
+/N:
+
+This restricts the number of drives that can be 
+used from PC Soft, for example, if you have 4 
+CD-ROM drives and you use the switch /N:2, 
+then only the first two drives will be usable 
+from PC Soft. If this switch is not specified 
+then all of the drives will be accessible.
+
+/D:
+
+This switch allows the device driver name to 
+be changed. You are advised not to change 
+this switch as it must then also be changed 
+for MSCDEX.EXE.
+
+MS-DOS CD-ROM Extensions
+
+The file containing the MS-DOS CD-ROM extensions is called 
+MSCDEX.EXE. This is configured by entering a statement such as 
+this in AUTOEXEC.BAT:
+
+C:\DRIVERS\MSCDEX /D:MSCD001 /L:F
+
+Parameter switches are:
+
+Parameter
+
+Use
+
+/D:
+
+Specifies the CD-ROM device driver name - 
+for example MSCD001 - which must match 
+that used in CONFIG.SYS.
+
+/L:
+
+Specifies the drive letter of the first CD-ROM 
+drive
+
+/M:
+
+Specifies the number of cache buffers for 
+MSCDEX.EXE (8 - 15), the default being 8.
+
+/V:
+
+Displays verbose message during boot-up, 
+detailing memory usage and diagnostic 
+information.
+
+/S:
+
+Instructs MSCDEX.EXE to patch DOS to allow 
+CD-ROM drive sharing on an MS-NET based 
+network server.
+
+This parameter is not used by PC Soft.
+
+/E:
+
+Instructs MSCDEX.EXE to use extended 
+memory if available.
+
+
+Interfacing CDs and RISC OS
+___________________________
+
+Introduction
+
+CDFS is made up from three modules: the CDFS module itself, the 
+CDFSDriver module, and the CDFSFiler module. In general, the 
+SWIs provided by these modules are reserved for internal use, and 
+you must not use them in your own code, otherwise unpredictable 
+results may occur. You should access files stored on CD-ROMs 
+using the same * Commands and SWI calls with which you would 
+access any other filing system; see the FileSwitch chapter of the 
+RISC OS 3 Programmer's Reference Manual.
+
+However, RISC OS itself does not provide any facilities for you to 
+use the audio facilities of a CD-ROM drive; these facilities are 
+instead provided by the CDFS and CDFSDriver SWIs detailed below. 
+You should only use these SWIs for accessing audio, and you must 
+not use any other CDFS or CDFSDriver SWIs.
+
+The SWI calls
+
+All SWIs conform to the RISC OS standard insofar as:
+
+* Any registers not explicitly defined as result parameters are 
+preserved.
+
+* The processor flags N, Z and C are preserved.
+
+* Errors are indicated by setting V and returning with R0 pointing 
+at an error block. (If the bit 17 clear version is called, control 
+passes to the error handler instead.)
+
+* The SWI cannot be called from the background unless this is 
+specifically documented.
+
+* All SWIs may be called from interrupt and event routines.
+
+but:
+
+* No CDFSDriver SWIs preserve the interrupt state.
+
+* No CDFSDriver SWIs are re-entrant.
+
+CDFS SWI calls
+
+CDFS_ConvertDriveToDevice (SWI &41E80)
+
+Converts a logical drive number to a physical drive number.
+
+On entry
+
+R0 = logical drive number
+
+On exit
+
+R0 preserved
+R1 = physical drive number
+
+Use
+
+This call converts a logical drive number to a physical drive number. 
+You can then use the physical drive number to produce a CDFS 
+control block, which you have to pass when calling CDFSDriver 
+SWIs. For details of how to construct the block, see below.
+
+This call returns an error if the logical drive is not known.
+
+CDFSDriver SWI calls
+
+CDFS control blocks
+
+Before you can access a CD-ROM drive using any of the CDFSDriver 
+SWIs, you need to set up a CDFS control block, as described below. 
+When you call any of the SWIs, you pass a pointer to the block in R7.
+
+A CDFS control block describes a physical device to the 
+CDFS_Driver module, so that it can use the correct routines. 
+Consequently there must be one block for each CD-ROM drive to be 
+accessed. Once set up, the block remains valid until the next CDFS 
+initialisation. CDFS may alter a block's contents, but you must not 
+do so yourself, nor must you save a block and use it in another 
+session.
+
+Each CDFS control block is five words long. To construct a block for 
+a particular logical drive, you must:
+
+1 Allocate memory for the block.
+
+2 Call CDFS_ConvertDriveToDevice to convert that drive's logical 
+number to a physical drive number.
+
+3 Copy the returned physical drive number into the block as 
+follows:
+
+Bits from         Place   Word   Bits   of CDFS control block 
+physical drive    in:                        
+number
+
+
+0 - 2                      0     0-2
+3 - 4                      1     0-1
+5 - 7                      2     0-2
+8 - 15                     3     0-7
+16 - 31                    4     0-15
+
+All bits of the control block not mentioned above must be 
+initialised to zero. The whole process can be done as follows:
+
+word 0 = (drive_number AND 7)
+word 1 = (drive_number AND &18) >> 3
+word 2 = (drive_number AND &E0) >> 5
+word 3 = (drive_number AND &FF00) >> 8
+word 4 = (drive_number AND &FFFF0000) >> 16
+
+Addressing modes
+
+Locations on a CD are specified as one word addresses. You can use 
+three different addressing modes:
+
+Addressing mode     Meaning
+
+0                 Logical block addressing
+1                 Red Book addressing
+2                 Physical block addressing
+
+Logical block addressing
+
+A logical block address gives an offset in blocks from the start of the 
+CD's data area.
+
+Red Book addressing
+
+A Red Book address gives a time offset from the CD's first frame, 
+made up as follows from the MM:SS:FF location defined in the Red 
+Book:
+
+Byte    Mnemonic    Meaning
+
+0         FF     Frame number (0 - 74)
+1         SS     Seconds (0 - 59)
+2         MM     Minutes (0 - 99)
+3                Undefined
+
+There are 75 frames per second.
+
+Physical Block Addressing
+
+A physical block address gives an offset in blocks from the first block 
+on the CD.
+
+CD_OpenDrawer (SWI &41247)
+
+Stops the CD spinning, opens the drawer and ejects the caddy
+
+On entry
+
+R7 = pointer to CDFS control block
+
+On exit
+
+R7 preserved
+
+Use
+
+This call stops the CD spinning, opens the drawer and ejects the 
+caddy. The call fails and returns an error if the drawer has previously 
+been locked using CD_EjectButton or *Lock.
+
+CD_EjectButton (SWI &41248)
+
+Enables or disables CD ejection
+
+On entry
+
+R0 = 0 (to enable ejection) or 1 (to disable ejection)
+R7 = pointer to CDFS control block
+
+On exit
+
+R0, R7 preserved
+
+Use
+
+This call enables or disables CD ejection. It is used by the *Lock 
+command.
+
+CD_EnquireAddress (SWI &41249)
+
+Returns the current address of the head
+
+On entry
+
+R0 = addressing mode, for returned head location
+R7 = pointer to CDFS control block
+
+On exit
+
+R0 = head address
+R7 preserved
+
+Use
+
+This call returns the current address of the head. You can use it 
+while playing audio to determine which section of audio is playing.
+
+CD_PlayAudio (SWI &4124B)
+
+Attempts to play a section of a CD as audio, specified by address
+
+On entry
+
+R0 = addressing mode, of parameters
+R1 = start address of play section
+R2 = end address of play section
+R7 = pointer to CDFS control block
+
+On exit
+
+R0-R2, R7 preserved
+
+Use
+
+This call attempts to play a section of a CD as audio, specified by 
+address. If the section contains non-audio information, the results 
+are drive-dependent; you will not necessarily get an error returned, 
+and some drives may still attempt to play the data. We therefore 
+recommend you first use calls to CD_EnquireTrack to find if the 
+section you wish to play consists entirely of audio.
+
+CD_PlayTrack (SWI &4124C)
+
+Attempts to play a section of a CD as audio, specified by track
+
+On entry
+
+R0 = track number at which to start playing (1 - 99)
+R1 = 255 to play to end of CD, or 254 to play to end of track
+R7 = pointer to CDFS control block
+
+On exit
+
+R0, R1, R7 preserved
+
+Use
+
+This call attempts to play a section of a CD as audio, specified by 
+track. If the section contains non-audio information, an error is 
+returned.
+
+CD_AudioPause (SWI &4124D)
+
+Controls pausing of audio playing
+
+On entry
+
+R0 = 0 to turn off pausing, if pause was in effect, or 1 to turn on
+ pausing, if audio was playing
+R7 = pointer to CDFS control block
+
+On exit
+
+R0, R7 preserved
+
+Use
+
+This call controls pausing of audio playing.
+
+CD_EnquireTrack (SWI &4124E)
+
+Returns the track range of a CD, or information on a specified track
+
+On entry
+
+R0 = 0 to return track range, or a valid track number
+R1 = pointer to 5 byte block
+R7 = pointer to CDFS control block
+
+On exit
+
+R0, R1, R7 preserved
+
+Use
+
+This call returns the track range of a CD, or information on a 
+specified track. The information is returned in the block pointed to 
+by R1.
+
+If R0 = 0 on entry, the track range is returned in the block as follows:
+
+Byte      Contents
+
+0     First track on CD (1-99)
+1     Last track on CD (1-99)
+2-4   Corrupted
+
+Track numbers do not necessarily start at 1.
+
+If R0 is a valid track number on entry, then information about that 
+track is returned in the block:
+
+Byte       Contents
+
+0-3   Logical block address of track start (ie Mode 0 
+      address)
+4     Audio control bits specifying the type of 
+      information the track holds:
+
+      Bits      Meaning
+       0      0 -> audio information, 1 -> data information
+       1      0 -> 4 channel sound,   1 -> 2 channel sound
+       2-7    Reserved
+
+CD_StopDisc (SWI &41252)
+
+Stops a CD playing
+
+On entry
+
+R7 = pointer to CDFS control block
+
+On exit
+
+R7 preserved
+
+Use
+
+This call stops a CD playing. You can use it to stop prematurely an 
+audio play request.
+
+CD_DiscUsed (SWI &41253)
+
+Returns the size of the CD currently in the drive
+
+On entry
+
+R0 = addressing mode, for returned size
+R1 = pointer to 8 byte block
+R7 = pointer to CDFS control block
+
+On exit
+
+R0 preserved
+R1 corrupted
+R7 preserved
+
+Use
+
+This call returns the size of the CD currently in the drive. The call 
+works with audio CDs as well as with CD-ROMs. The size is returned 
+in the block pointed to by R1 on entry:
+
+Bytes    Contents
+
+0-3      Size of CD
+4-7      Size of blocks on CD, in bytes (usually 2048)
+
+Note that R1 may be corrupted on exit.
+
+CD_AudioStatus (SWI &41254)
+
+Returns the current audio status of the drive
+
+On entry
+
+R7 = pointer to CDFS control block
+
+On exit
+
+R0 = audio status
+R7 preserved
+
+Use
+
+This call returns the current audio status of the drive, which may 
+have one of the following values:
+
+Value   Meaning
+
+0       Currently playing audio
+1       Currently paused
+2       Reserved (has no meaning at present)
+3       Audio play successfully completed
+4       Error occurred during last audio play
+5       Audio play has not been requested
+
+To maintain drive independence, you should always treat values 3 
+and 5 in the same way.
+
+Soft-loadable Drivers
+
+A soft-loadable driver must register itself with the CDFS_Driver 
+module before it can be used. Once the driver has been registered, 
+CDFS will make a SCSI_Inquiry command to obtain information 
+about a SCSI device at a specific SCSI address (i.e. device id, LUN, 
+card). The results of this Inquiry command are then passed to the 
+soft-loaded driver to check if it recognises the drive. If the 
+soft-loaded driver does recognise the drive, then it must return 
+without an error, in which case CDFS will allocate this soft-loaded 
+driver as the code which is called each time information is required 
+from the device.
+
+For soft-loadable drivers which are not SCSI, the same procedure 
+must be followed. In this case however, CDFS, when passing the 
+Inquiry command, will pass an error block pointed to by R0 instead 
+for any SCSI address which is not occupied by a device. The 
+soft-loaded driver will check for this error block, and when seen will 
+return a non-error as above. CDFS will then allocate the driver as 
+before. Thus the non-SCSI soft-loaded CD-ROM device driver is 
+effectively allocated a SCSI address which is not occupied by any 
+other device. CDFS will then access the driver in the usual manner, 
+passing the SCSI address in the control block to the specific driver 
+which can handle the command in the most appropriate way for the 
+specific hardware regardless of its type. 
+
+SWI handler entry conditions
+
+When the soft-loadable driver registers itself with the CDFSDriver, it 
+passes the address of a handler for SWI calls. CDFSDriver passes 
+`CD_' SWIs to this handler with the following entry conditions:
+
+On entry
+
+R0 - R6 = Whatever values the various CD_ SWIs use 
+
+R7 = pointer to a control block   
+
+ Offset         Meaning
+
+  0        SCSI device id (0-7)
+  4        SCSI card number (0-3, usually 0)
+  8        Logical Unit Number (0-7, usually 0)
+  12       Drive type for this module 
+
+R11= the number of the CD_SWI, i.e.     0 -> CD _ReadData, 
+                                        1 -> CD_SeekTo etc
+R12 = pointer to the workspace for this module 
+R13 = pointer to a full descending stack, approx. 1024 bytes 
+R14 = address to return to
+
+On exit
+
+R0 - R12 and R14 corrupted
+
+CD_Register  (SWI & 41260)
+
+Registers the soft-loadable driver with the CDFSDriver module.
+
+On entry
+
+R0 = pointer to a block
+
+Offset  Meaning
+
+  0    Information word for CDFSDriver module:
+       Bits  Meaning
+       0 - 5  The number of CD commands recognised, 
+       currently 31, maximum 63 
+       6  If set then use the SCSI 1 read data 
+       command 
+       7  If set then use the SCSI 1 seek command 
+       9 - 31  Reserved   (must be zero)
+
+  4    Number of times registered (should be set to zero             
+       and will be updated by CDFSDriver)
+  8    Number of drive types recognised by this driver
+  12   Unused (must be zero)
+  16   Unused (must be zero)
+
+R1 = pointer to a 1-word special tag (&EE5OEE50), followed by 
+handler code     
+
+R2 = pointer to workspace for the soft-loadable module (passed in 
+R12 to the handler)
+
+On exit
+
+  Offset  Meaning
+
+    12    A pointer to a routine to convert logical blocks to 
+          minutes, seconds, frames
+    16    A pointer to a routine to convert minutes, seconds, 
+          frames to logical blocks 
+
+Use
+
+This call registers the soft-loadable driver with the CDFSDriver 
+module. The block pointed to by R0 on entry must be in RAM, 
+whereas anything else, i.e. the code for each CD _SWI, can be in 
+ROM. The block must stay put in the memory so that CDFSDriver 
+can check it when detecting drive types. 
+
+CD_Unregister       (SWI &41261)
+
+Removes the soft-loadable driver from the CDFSDriver module.
+
+On entry
+
+R0 = pointer to a block                   
+
+   Offset   Meaning
+
+      0     Information word for CDFSDriver module block 
+
+            Bits      Meaning
+            0-5   The number of CD commands recognised, 
+                  currently 31, maximum 63 
+            6     If set then use all SCSI 2 commands and 
+                  ignore bits 7 and 8 
+            7     If set then use the SCSI 2 read data 
+                  command 
+            8     If set then use the SCSI 2 seek command 
+            9-31 RESERVED (must be zero)
+
+      4     Number of times registered (should be sent to 1 to 
+            indicate that it has been registered already)
+      8     UNUSED
+
+R1 = pointer to a special tag (&EE5OEE50 = 1 word) followed by the 
+handler code.
+
+On exit
+
+-
+
+Use
+
+Removes the soft-loadable driver from the CDFSDriver module. The 
+block pointed to by R0 on entry must be in RAM, whereas anything 
+else, i.e. the code for each CD _ SWI, can be in the ROM.
+
+CD_ByteCopy       (SWI &41262)
+
+Fast memory copy routine.
+
+On entry      
+
+R1 = pointer to the source             
+R2 = pointer to the destination
+R3 = number of bytes to copy
+
+On exit
+
+All registers preserved 
+
+Use
+
+Fast memory copy routine which provides an efficient way of 
+copying any number of bytes, word-aligned or not.
+
+CD_Identify (SWI & 41263) 
+
+Identifies the drive type of a CD-ROM drive.
+
+On entry
+
+R7 = pointer to CDFS control block
+     (as obtained from SWI CDFS_ConvertDriveToDevice)
+
+
+On exit
+
+R0 - Rl preserved       
+R2 = drive type given by CDFS driver, or - 1 if type not recognised
+
+Use
+
+This call gets the drive type of a CD-ROM drive, so that other 
+CD_SWIs can be made. It can be made by CDFS, the PCEmulator 
+driver or !CDPlayer.
+
+

Doc/Notes

+; -> Notes for CDFSDriver
+
+
+ General flow of driver:
+ -----------------------
+
+ eg/ after SWI CD_..
+
+1.  Entry with R11 = SWI number AND 63
+               R12 -> workspace
+               R13 -> stack
+               R14 = return address
+
+2.  Is SWI CD_.. a known SWI ? ( eg/ R11 is too big )
+
+3.  Check control block if needed
+
+4.  Clear Command Descriptor Block ( thats the bit sent through SCSI_Op )
+
+5.  Clear misc. vars.
+
+6.  Put opcode for Command Descriptor Block in.
+
+7.  Put parametersize, numberofbytesreturned, r/w/nodata and storagearea in
+
+8.  Jump to routine for each SWI, if nec.
+
+9.  Use either the Acorn conforming SCSI_Op or the Oak one
+    Either way registers need to be set
+
+10. On error branch to error handler - see ( 13 )
+
+11. Jump to routine for each SWI, if nec.
+
+12. Go 'Home' or 'PreHome' END basically
+
+ Error !
+
+13. If error is 'Unit attention' or 'Check condition' THEN setdischaschanged
+
+14. If error THEN jump to routine for each SWI if nec.
+
+15. Return error to caller of SWI with overflow set and R0 -> error block
+    Operating System works out the rest
+    ( ie/ if XCD_.. was called instead of CD_.. )
+
+
+
+
+ Meaning of number returned by CD_Supported
+
+  Bits    Description: ( if set )
+  ----    -----------------------
+  0 - 2   Level to which CD_AudioControl is supported ( 0 to 7 )
+          0 = no support at all
+          1 = supported to level 0
+          7 = supported to level 6
+    3     CD_Prefetch supported
+    4     CD_CloseDrawer supported
+    5     CD_AudioLevel supported
+  6 - 31  RESERVED ( 0 )

LICENSE

+
+                                 Apache License
+                           Version 2.0, January 2004
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+
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+   6. Trademarks. This License does not grant permission to use the trade
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+   7. Disclaimer of Warranty. Unless required by applicable law or
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+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

Makefile

+# Copyright 1996 Acorn Computers Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Makefile for CDFS Driver
+#
+# ***********************************
+# ***    C h a n g e   L i s t    ***
+# ***********************************
+# Date       Name   Description
+# ----       ----   -----------
+# 25-May-94  AMcC   Created.
+# 23-Feb-95  AMcC   Resources now copied to CDFSRes
+#
+
+#
+# Paths
+#
+EXP_HDR = <export$dir>
+
+#
+# Generic options:
+#
+MKDIR    = cdir
+AS       = aasm
+CP       = copy
+RM       = remove
+
+CFLAGS   = -c -depend !Depend -IC:
+AFLAGS   = -depend !Depend -Stamp -quit -module
+CPFLAGS  = ~cfr~v
+
+#
+# Program specific options:
+#
+COMPONENT = CDFSDriver
+EXPORTS   = ${EXP_HDR}.CDROM ${EXP_HDR}.CDErrors
+SOURCE    = s.Main
+TARGET    = rm.CDFSDriver
+RDIR      = Resources
+LDIR      = ${RDIR}.${LOCALE}
+CDFSRES   = <src$dir>.OS_Core.FileSys.CDFS.CDFSRes
+RESDIR    = ${CDFSRES}.Resources.${Locale}.Resources.CDFSDriver.${COMPONENT}
+
+#
+# Generic rules:
+#
+rom: ${TARGET}
+	@echo ${COMPONENT}: rom module built
+
+export: ${EXPORTS}
+	@echo ${COMPONENT}: export complete
+
+install_rom: ${TARGET}
+	${CP} ${TARGET} ${INSTDIR}.${COMPONENT} ${CPFLAGS}
+	@echo ${COMPONENT}: rom module installed
+
+resources:
+	@echo ${COMPONENT}: Resources are in CDFSRes
+
+clean:
+	${RM} ${TARGET}
+	@echo ${COMPONENT}: cleaned
+
+${TARGET}: ${SOURCE}
+	${AS} ${AFLAGS} -To $@ -From ${SOURCE}
+
+${EXP_HDR}.CDROM: hdr.CDROM
+	${CP} hdr.CDROM $@ ${CPFLAGS}
+
+${EXP_HDR}.CDErrors: hdr.CDErrors
+	${CP} hdr.CDErrors $@ ${CPFLAGS}
+
+# Dynamic dependencies:

MkClean,fd7

+| Copyright 1996 Acorn Computers Ltd
+|
+| Licensed under the Apache License, Version 2.0 (the "License");
+| you may not use this file except in compliance with the License.
+| You may obtain a copy of the License at
+|
+|     http://www.apache.org/licenses/LICENSE-2.0
+|
+| Unless required by applicable law or agreed to in writing, software
+| distributed under the License is distributed on an "AS IS" BASIS,
+| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+| See the License for the specific language governing permissions and
+| limitations under the License.
+|
+Dir <Obey$Dir>
+amu_machine clean

MkRom,fd7

+| Copyright 1996 Acorn Computers Ltd
+|
+| Licensed under the Apache License, Version 2.0 (the "License");
+| you may not use this file except in compliance with the License.
+| You may obtain a copy of the License at
+|
+|     http://www.apache.org/licenses/LICENSE-2.0
+|
+| Unless required by applicable law or agreed to in writing, software
+| distributed under the License is distributed on an "AS IS" BASIS,
+| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+| See the License for the specific language governing permissions and
+| limitations under the License.
+|
+Dir <Obey$Dir>
+amu_machine rom

Version

+; > Version
+
+        GBLA    Version
+        GBLS    VString
+        GBLS    Date
+
+Version SETA    233                     ; CDFSDriver
+VString SETS    "2.33"       
+Date    SETS    "03 Feb 1995"          
+        END

hdr/CDErrors

+; Copyright 1996 Acorn Computers Ltd
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     http://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+;
+; >Hdr.CDFSErrors
+
+; *********************************************************************************************
+; ** CDFS Driver errors                                                                      **
+; *********************************************************************************************
+
+                                ^ &00803400
+
+CDFSDRIVERERROR__UNUSED                        #         1               ;  0
+CDFSDRIVERERROR__BAD_ALIGNMENT                 #         1               ;  1
+CDFSDRIVERERROR__DRIVE_NOT_SUPPORTED           #         1               ;  2
+CDFSDRIVERERROR__BAD_MODE                      #         1               ;  3
+CDFSDRIVERERROR__INVALID_PARAMETER             #         1               ;  4
+CDFSDRIVERERROR__NOT_AUDIO_TRACK               #         1               ;  5
+CDFSDRIVERERROR__NO_CADDY                      #         1               ;  6
+CDFSDRIVERERROR__NO_DRIVE                      #         1               ;  7
+CDFSDRIVERERROR__INVALID_FORMAT                #         1               ;  8
+CDFSDRIVERERROR__BAD_MINUTES                   #         1               ;  9
+CDFSDRIVERERROR__BAD_SECONDS                   #         1               ; 10
+CDFSDRIVERERROR__BAD_BLOCKS                    #         1               ; 11
+CDFSDRIVERERROR__PHYSICAL_BLOCK_ERROR          #         1               ; 12
+CDFSDRIVERERROR__DRAWER_LOCKED                 #         1               ; 13
+CDFSDRIVERERROR__WRONG_DATA_MODE               #         1               ; 14
+CDFSDRIVERERROR__CHANNEL_NOT_SUPPORTED         #         1               ; 15
+CDFSDRIVERERROR__BAD_DEVICE_ID                 #         1               ; 16
+CDFSDRIVERERROR__BAD_CARD_NUMBER               #         1               ; 17
+CDFSDRIVERERROR__BAD_LUN_NUMBER                #         1               ; 18
+CDFSDRIVERERROR__NO_SUCH_TRACK                 #         1               ; 19
+CDFSDRIVERERROR__FAULTY_DISC                   #         1               ; 20
+CDFSDRIVERERROR__NO_SUCH_BLOCK                 #         1               ; 21
+CDFSDRIVERERROR__DRIVE_DOES_NOT_SUPPORT_THAT   #         1               ; 22
+CDFSDRIVERERROR__DRIVER_NOT_PRESENT            #         1               ; 23
+CDFSDRIVERERROR__SWI_NOT_SUPPORTED             #         1               ; 24
+CDFSDRIVERERROR__TOO_MANY_DRIVERS              #         1               ; 25
+CDFSDRIVERERROR__NOT_REGISTERED                #         1               ; 26
+
+        END

hdr/CDMacros

+; Copyright 1996 Acorn Computers Ltd
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     http://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+;
+;; -> macros
+;; =============================================
+;; Macros should be kept in ALPHABETICAL order !
+;; =============================================
+;;
+;;   CDFSDriverError
+;;   CLV
+;;   Debug
+;;   Debug0
+;;   DebugDisplay
+;;   DebugWaitForAKey
+;;
+
+;************************************
+; This allows nice errors from CDFS driver
+;************************************
+        MACRO
+$label  CDFSDriverError $name, $message
+$name DCD CDFSDriverErrorNumber
+       = "$message"
+       = 0
+CDFSDriverErrorNumber SETA CDFSDriverErrorNumber + 1
+ ALIGN
+        MEND
+
+; *******************************************
+; *** Clear overflow flag - will set nzCv ***
+; *******************************************
+; Note: (AMcC 02-Feb-95)
+; Not the same as CLRV Macro in Global Hdr CPU.Generic26
+;
+        MACRO
+$label  CLV    $cond
+$label  EORVSS pc, pc, # Overflow_Flag
+        MEND
+
+; **********************************************************
+; This will print a message if 'debug' = ON.
+; **********************************************************
+        MACRO
+$label  Debug $string,$nl
+$label  [ debug=ON
+        STASH r14
+         [ hostvdu=ON
+        SWI XHostFS_HostVdu
+         ]
+        SWI XOS_WriteS
+        = "$string"
+         [ "$nl"="NL"
+        = 13,10
+         ]
+        = 0
+        ALIGN
+         [ hostvdu=ON
+        SWI XHostFS_TubeVdu
+         ]
+        GRAB r14
+        ]
+        MEND
+
+; **********************************************************
+; This will perform a XOS_Write0 if 'debug' = ON.
+; **********************************************************
+        MACRO
+$label  Debug0 $string,$nl
+$label  [ debug=ON
+        STASH r14
+         [ hostvdu=ON
+        SWI XHostFS_HostVdu
+         ]
+        SWI XOS_Write0
+         [ "$nl"="NL"
+        SWI XOS_NewLine
+         ]
+         [ hostvdu=ON
+        SWI XHostFS_TubeVdu
+         ]
+        GRAB r14
+        ]
+        MEND
+
+; **********************************************************
+; This will perform a Display if 'debug' = ON.
+; **********************************************************
+        MACRO
+$label  DebugDisplay $string,$nl
+$label  [ debug=ON
+        STASH r14
+         [ hostvdu=ON
+        SWI XHostFS_HostVdu
+         ]
+        Display $string,$nl
+         [ hostvdu=ON
+        SWI XHostFS_TubeVdu
+         ]
+        GRAB r14
+        ]
+        MEND
+
+; **********************************************************
+; This will perform a wait-for-key if 'debug' = ON.
+; **********************************************************
+        MACRO
+$label  DebugWaitForAKey
+$label  [ debug=ON
+        STASH "r0-r2,r14"
+        MOV R0, #122
+01
+        SWI XOS_Byte
+        CMP R1, #&FF
+        BEQ %BT01
+        GRAB "r0-r2,r14"
+        ]
+        MEND
+
+        END

hdr/CDROM

+; Copyright 1996 Acorn Computers Ltd
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     http://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+;
+        SUBT    Exported CDROM Driver constants
+
+OldOpt  SETA    {OPT}
+        OPT     OptNoList+OptNoP1List
+
+; ***********************************
+; ***    C h a n g e   L i s t    ***
+; ***********************************
+
+; Date       Name  Description
+; ----       ----  -----------
+; 20-Dec-94  AMcC  Created
+; 04-Jan-95  AMcC  Undocumented SWIs commented as Private
+;                  (some may cause damage to drive if used incorrectly)
+;                  Not marked as NOPs 'cause some are used by CDFSDriver
+;
+
+SWIClass        SETS CDROMSWI_Name
+
+        ^       CDROMSWI_Base   ; &41240
+
+        AddSWI Version          ;  +0
+        AddSWI ReadData         ;  +1
+        AddSWI SeekTo           ;  +2
+        AddSWI DriveStatus      ;  +3
+        AddSWI DriveReady       ;  +4
+        AddSWI GetParameters    ;  +5     Private
+        AddSWI SetParameters    ;  +6     Private
+        AddSWI OpenDrawer       ;  +7
+        AddSWI EjectButton      ;  +8
+        AddSWI EnquireAddress   ;  +9
+        AddSWI EnquireDataMode  ; +10     Private
+        AddSWI PlayAudio        ; +11
+        AddSWI PlayTrack        ; +12
+        AddSWI AudioPause       ; +13
+        AddSWI EnquireTrack     ; +14
+        AddSWI ReadSubChannel   ; +15     Private
+        AddSWI CheckDrive       ; +16
+        AddSWI DiscChanged      ; +17     Private
+        AddSWI StopDisc         ; +18
+        AddSWI DiscUsed         ; +19
+        AddSWI AudioStatus      ; +20
+        AddSWI Inquiry          ; +21
+        AddSWI DiscHasChanged   ; +22     Private
+        AddSWI Control          ; +23
+        AddSWI Supported        ; +24     Private
+        AddSWI Prefetch         ; +25
+        AddSWI Reset            ; +26
+        AddSWI CloseDrawer      ; +27     Private
+        AddSWI IsDrawerLocked   ; +28     Private
+        AddSWI AudioControl     ; +29     Private
+        AddSWI LastError        ; +30
+        AddSWI AudioLevel       ; +31     Private
+        AddSWI Register         ; +32
+        AddSWI Unregister       ; +33
+        AddSWI ByteCopy         ; +34     Private
+        AddSWI Identify         ; +35
+        AddSWI ConvertToLBA     ; +36
+        AddSWI ConvertToMSF     ; +37
+        AddSWI ReadAudio        ; +38
+        AddSWI ReadUserData     ; +39
+        AddSWI SeekUserData     ; +40
+        AddSWI GetAudioParms    ; +41
+        AddSWI SetAudioParms    ; +42
+
+        OPT     OldOpt
+        END

hdr/hashes

+; Copyright 1996 Acorn Computers Ltd
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     http://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+;
+; Hash defines
+
+X_bit                 *      1:SHL:17
+XCD_BaseNumber        *      (CDROMSWI_Base:OR:X_bit)
+
+; ***************************************************************************
+; ***           Reason codes passed to soft-load drivers                  ***
+; ***************************************************************************
+
+                       ^ 0
+DRIVER__ReadData           #        1                      ;  0
+DRIVER__SeekTo             #        1                      ;  1
+DRIVER__DriveStatus        #        1                      ;  2
+DRIVER__DriveReady         #        1                      ;  3
+DRIVER__GetParameters      #        1                      ;  4
+DRIVER__SetParameters      #        1                      ;  5
+DRIVER__OpenDrawer         #        1                      ;  6
+DRIVER__EjectButton        #        1                      ;  7
+DRIVER__EnquireAddress     #        1                      ;  8
+DRIVER__EnquireDataMode    #        1                      ;  9
+DRIVER__PlayAudio          #        1                      ; 10
+DRIVER__PlayTrack          #        1                      ; 11
+DRIVER__AudioPause         #        1                      ; 12
+DRIVER__EnquireTrack       #        1                      ; 13
+DRIVER__ReadSubChannel     #        1                      ; 14
+DRIVER__CheckDrive         #        1                      ; 15
+DRIVER__DiscChanged        #        1                      ; 16
+DRIVER__StopDisc           #        1                      ; 17
+DRIVER__DiscUsed           #        1                      ; 18
+DRIVER__AudioStatus        #        1                      ; 19
+DRIVER__Inquiry            #        1                      ; 20
+DRIVER__DiscHasChanged     #        1                      ; 21
+DRIVER__Control            #        1                      ; 22
+DRIVER__Supported          #        1                      ; 23
+DRIVER__Prefetch           #        1                      ; 24
+DRIVER__Reset              #        1                      ; 25
+DRIVER__CloseDrawer        #        1                      ; 26
+DRIVER__IsDrawerLocked     #        1                      ; 27
+DRIVER__AudioControl       #        1                      ; 28
+DRIVER__AudioLevel         #        1                      ; 29
+DRIVER__Identify           #        1                      ; 30
+DRIVER__ReadAudio          #        1                      ; 31
+DRIVER__ReadUserData       #        1                      ; 32
+DRIVER__SeekUserData       #        1                      ; 33
+DRIVER__GetAudioParms      #        1                      ; 34
+DRIVER__SetAudioParms      #        1                      ; 35
+
+;***************************************************************************
+
+OAK                   *       1
+ACORN                 *       0
+
+ON * 1
+OFF * 0
+
+TRUE * 1
+FALSE * 0
+
+hostvdu      * ON               ; debug to host
+debug        * OFF              ; prints debugging information
+commanddebug * OFF              ; Keeps a list of SWI's called
+
+CheckConfiguredDrives   * ON    ; don't start up if no drives configured
+
+;------------------------------------------------------------------
+
+RESERVED              *       0
+CONTROLBYTE           *       0
+
+
+LBAFormat             *       0
+MSFFormat             *       1
+PBFormat              *       2
+
+SmallestMode          *       1
+LargestMode           *       2
+
+;*********************************************************************************************
+; Details on data modes (mode 1, mode 2 form 1, mode 2 form 2)
+;*********************************************************************************************
+
+mode1datasize             *       2048
+mode2datasize             *       2340
+mode1datasizeHBLB         *       &00080000 ; high/byte low/byte of above
+mode2datasizeHBLB         *       &20090000 ;
+
+MODE2__HEADER_M           *          0
+MODE2__HEADER_S           *          1
+MODE2__HEADER_F           *          2
+MODE2__HEADER_MODE        *          3
+MODE2__HEADER_SIZE        *          4
+
+MODE2__SUB_HEADER_FILE    *          0    ; These fields are repeated at 4,5,6,7
+MODE2__SUB_HEADER_CHANNEL *          1    ;
+MODE2__SUB_HEADER_SUBMODE *          2    ;
+MODE2__SUB_HEADER_CODING  *          3    ;
+MODE2__SUB_HEADER_SIZE    *          8
+
+MODE2__TOTALHEADERSIZE    *      MODE2__HEADER_SIZE + MODE2__SUB_HEADER_SIZE
+
+SUBMODE__FORM             *       (1:SHL:5)
+
+USERDATA__MODE2FORM1      *       2048
+USERDATA__MODE2FORM2      *       2324
+
+;*********************************************************************************************
+
+
+bit17                 *   2_100000000000000000
+
+MaxNumberOfSeconds    *      59
+MinNumberOfSeconds    *       2
+MaxNumberOfBlocks     *      74
+
+MaxSCSIcardnumber     *       3
+MaxLUN                *       3
+MaxSCSIdeviceID       *       6
+
+PhysicalBlockDifference *   2 * ( MaxNumberOfBlocks + 1 ) ; 2 seconds
+
+SWIBaseNumber         *   CDROMSWI_Base
+
+ErrorBlock            *   &00803400
+
+HARDRAMLOCATION         *       &8A
+BITSUSEDBYDRIVENUMBER *    2_11111
+BITSUSEDBYBUFFER      *    2_11100000
+
+;******************* Used for macro to allow nice error blocks ***********
+
+ GBLA CDFSDriverErrorNumber
+CDFSDriverErrorNumber SETA ErrorBlock
+
+
+;******************* SCSI error numbers  ***************************
+
+SCSIErrorNumber       *   &00020100
+
+                      ^   SCSIErrorNumber
+
+NoRoom                # 1     ; 0
+UnknownSCSISWI        # 1     ; 1
+UnknownReason         # 1     ; 2
+FailedBusReset        # 1     ; 3
+InvalidHostId         # 1     ; 4
+InvalidDeviceId       # 1     ; 5
+gap                   # 3     ; 6 - 8
+DeviceNotIdle         # 1     ; 9
+TimeoutSelection      # 1     ; 10
+TimeoutOther          # 1     ; 11
+CommandQueueError     # 1     ; 12
+CommandQueFull        # 1     ; 13
+ReservationError      # 1     ; 14
+InvalidParameters     # 1     ; 15
+ParameterError        # 1     ; 16
+NotFromIRQ            # 1     ; 17
+OperationAborted      # 1     ; 18
+UnexpectedDisconnect  # 1     ; 19
+
+;***************** SCSI sense numbers ( TargetError )**********************
+
+SCSISenseNumber       *     &201C0
+                      ^     SCSISenseNumber
+
+NoSense               # 1   ; 0
+RecoveredError        # 1   ; 1
+NotReady              # 1   ; 2
+MediumError           # 1   ; 3
+HardwareError         # 1   ; 4
+IllegalRequest        # 1   ; 5
+UnitAttention         # 1   ; 6
+DataProtect           # 1   ; 7
+BlankCheck            # 1   ; 8
+VendorUnique          # 1   ; 9
+CopyAborted           # 1   ; 10
+AbortedCommand        # 1   ; 11
+Equal                 # 1   ; 12
+VolumeOverflow        # 1   ; 13
+Miscompare            # 1   ; 14
+ReservedSenseKey      # 1   ; 15
+
+
+;***************** SCSI status byte numbers *******************************
+
+SCSIStatusNumber      *     &20180
+                      ^     SCSIStatusNumber
+
+CheckCondition        # 1
+Busy                  # 1
+Unknown               # 1
+
+;***************************** Values for SCSI_Op ************************
+
+accesskey             *       1
+readdata              *      2_01000000000000000000000000
+;writedata             *      2_10000000000000000000000000
+nodata                *      2_00000000000000000000000000 ; = 0
+scatterliston         *     2_100000000000000000000000000
+scatterlistoff        *     2_000000000000000000000000000 ; = 0
+escapepollon          *    2_0000000000000000000000000000 ; = 0
+escapepolloff         * 1:SHL:27
+retryoff              *   2_00000000000000000000000000000 ; = 0
+retryon               *   2_10000000000000000000000000000
+backgroundon          *  2_100000000000000000000000000000
+backgroundoff         *  2_000000000000000000000000000000 ; = 0
+
+
+;I_bit                 *  &08000000
+FIRQ_Flag                   *   1:ROL:26
+IRQ_Flag                    *   1:ROL:27
+Overflow_Flag               *   1:ROL:28
+Carry_Flag                  *   1:ROL:29
+Zero_Flag                   *   1:ROL:30
+Negative_Flag               *   1:ROL:31
+
+
+;------------------------------------------------------------------
+; Structure of r7 -> control block
+;------------------------------------------------------------------
+                      ^ 0
+SdeviceIDoffset       #       4
+LScardnumberoffset    #       4
+LUNoffset             #       4
+drivetypeoffset       #       4
+control_block_size    #       0
+
+;------------------------------------------------------------------
+; Structure of register control block
+;------------------------------------------------------------------
+                      ^ 0
+RCB_INFOWORD          #       4
+RCB_REGISTERED        #       4
+RCB_DRIVETYPES        #       4
+
+;----------------------------------------------------------------------------------------------
+; The information word when registering
+;----------------------------------------------------------------------------------------------
+USE_SCSI_READ               * 1<<6
+USE_SCSI_SEEK               * 1<<7
+USE_SCSI_INQUIRY            * 1<<8
+USE_SCSI_CAPACITY           * 1<<9
+USE_SCSI_READY              * 1<<10
+USE_SCSI_STOPOPEN           * 1<<11
+USE_SCSI_CHECK              * 1<<12
+USE_SCSI_STATUS             * 1<<13
+USE_SCSI_CONTROL            * 1<<14
+USE_SCSI_PREFETCH           * 1<<15
+USE_SCSI_RESET              * 1<<16
+USE_PROPRIETARY_RUD         * 1<<17   ; = 1 if support own method of reading data
+USE_COMPLEX_RUD             * 1<<18   ; = 1 if want SCSI scatter list method of reading data
+USE_PROPRIETARY_SUD         * 1<<19   ; = 1 if support own method of seeking to data
+USE_COMPLEX_SUD             * 1<<20   ; = 1 if want SCSI scatter list method of seeking to data
+
+;----------------------------------------------------------------------------------------------
+; Maximum number of soft-loadable device drivers
+; REMEMBER that each soft-load driver can have 4 sub values and that all of this must fit into
+; 1 byte (see PC driver and CDFS).  ie/   2 bits for sub-value, 6 bits for main value
+;----------------------------------------------------------------------------------------------
+MAX_NUMBER_OF_DRIVERS  *  64
+
+
+
+;----------------------------------------------------------------------------------------------
+; CD_Supported values
+;
+; Meaning of number returned by CD_Supported
+;  Bits    Description: ( if set )
+;  ----    -----------------------
+;  0 - 2   Level to which CD_AudioControl is supported ( 0 to 7 )
+;          0 = no support at all
+;          1 = supported to level 0
+;          7 = supported to level 6
+;    3     CD_Prefetch supported
+;    4     CD_CloseDrawer supported
+;    5     CD_AudioLevel supported
+;  6 - 13  Number of different speeds supported by the drive - 1.
+;          ie/ Standard drives support 1 speed, so will return 0.
+;          The Sony 561 supports 2 speeds, so will return 1.
+;   14     CD_ReadAudio supported
+;   15     CD_Get/Set AudioParms supported
+;  16 - 31  RESERVED ( 0 )
+;----------------------------------------------------------------------------------------------
+
+NOAUDIOCONTROLSUPPORT     *  0
+AUDIOCONTROLSUPPORT1      *  2_1
+AUDIOCONTROLSUPPORT2      *  2_10
+AUDIOCONTROLSUPPORT3      *  2_11
+AUDIOCONTROLSUPPORT4      *  2_100
+AUDIOCONTROLSUPPORT5      *  2_101
+AUDIOCONTROLSUPPORT6      *  2_110
+AUDIOCONTROLSUPPORT7      *  2_111
+
+SUPPORT__PREFETCH         *  2_1000
+
+SUPPORT__CLOSE_DRAWER     *  2_10000
+
+SUPPORT__AUDIO_LEVEL      *  2_100000
+
+SUPPORT__SPEED_MULTIPLIER *  2_1000000
+
+SUPPORT__READ_AUDIO       *  1:SHL:14
+
+SUPPORT__AUDIO_PARMS      *  1:SHL:15
+
+;----------------------------------------------------------------------------------------------
+
+ END

rm/.gitignore

+*
+!.gitignore

s/ByteCopy

+; Copyright 1996 Acorn Computers Ltd
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     http://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+;
+; -> ByteCopy.s
+
+
+
+
+
+
+
+
+
+
+
+
+
+; This provides the CD_ByteCopy routine
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+;**************************************************************************
+; This is a highly optimised routine to move blocks of memory
+; It will deal with unword-aligned source and destinations
+
+; copied from pages 1000 to 1005 of PRM
+
+; R1 -> source                                    RCM was ere
+; R2 -> destination
+; R3 = number of bytes to copy
+
+;**************************************************************************
+
+cd_bytecopyinternal ROUT
+     STASH   "r0-r11, r14"
+
+cd_bytecopy
+
+;--------------------------
+; Any bytes to copy ?
+;--------------------------
+     TEQ     r3, #0
+     GRABS   "r0-r11, pc", EQ
+
+;--------------------------
+
+copy_bytes
+
+     TST r2, #3
+     BNE MovByt100                  ; destination not word aligned
+
+MovByt20       ; destination now word aligned. branched back to from below
+
+     TST r1, #3
+     BNE MovByt200                  ; source not word aligned
+
+; source & destination are now both word aligned
+; count is a byte value ( may not be a whole number of words )
+
+; Quick sort out of what we've got left to do
+
+     SUBS r3, r3, #4 * 4         ; Four whole words to do (or more) ?
+     BLT MovByt40                      ; no
+
+     SUBS r3, r3, #8 * 4 - 4 * 4 ; Eight whole words to do (or more) ?
+     BLT MovByt30
+
+
+MovByt25
+
+     LDMIA r1!, { r0, r4 - r9, r14 } ; NB. Order ! (?)
+     STMIA r2!, { r0, r4 - r9, r14 }
+
+     SUBS r3, r3, #8 * 4
+     BGE MovByt25                      ; do another 8 words
+
+     CMP r3, #-8 * 4                ; Quick test rather that chaining down
+     GRABS "r0-r11, pc", EQ         ; finished
+
+
+MovByt30
+
+     ADDS r3, r3, #8 * 4 - 4 * 4 ; Four whole words to do ?
+     BLT MovByt40
+
+     LDMIA r1!, { r0, r4 - r5, r14 } ; NB. Order ! (?)
+     STMIA r2!, { r0, r4 - r5, r14 }
+
+     GRABS "r0-r11, pc", EQ         ; finished
+
+     SUB r3, r3, #4 * 4
+
+
+MovByt40
+
+     ADDS r3, r3, #4 * 4 - 2 * 4   ; Two whole words to go ?
+     BLT MovByt50
+
+     LDMIA r1!, { r0, r14 } ; NB. Order ! (?)
+     STMIA r2!, { r0, r14 }
+
+     GRABS "r0-r11, pc", EQ         ; finished
+
+     SUB r3, r3, #2 * 4
+
+
+MovByt50
+
+     ADDS r3, r3, #2*4-1*4       ; One whole word to do ?
+     BLT MovByt60
+
+     LDR r0, [ r1 ], #4
+     STR r0, [ r2 ], #4
+
+     GRABS "r0-r11, pc", EQ         ; finished
+
+     SUB r3, r3, #1 * 4
+
+
+MovByt60
+
+     ADDS r3, r3, #1*4 - 0*4      ; No more to do ?
+     GRABS "r0-r11, pc", EQ         ; finished
+
+     LDR r0, [ r1 ]           ; store remaining 1,2 or 3 bytes
+
+
+MovByt70
+
+
+     STRB r0, [ r2 ], #1
+     MOV r0, r0, LSR #8
+     SUBS r3, r3, #1
+     BGT MovByt70
+
+     GRABS "r0-r11, pc"                 ; finished
+
+
+
+;Initial destination not word aligned.Loop doing bytes(1,2, or 3 )until it is
+
+MovByt100
+
+     LDRB r0, [ r1 ], #1
+     STRB r0, [ r2 ], #1
+     SUBS r3, r3, #1
+     GRABS "r0-r11, pc", EQ                ; finished
+
+     TST r2, #3
+     BNE MovByt100
+
+     B MovByt20                      ; Back to mainline code
+
+
+MovByt200;destination now word aligned,but source isn't. just r14 stacked here
+
+     AND r12, r1, #3       ; offset
+     BIC r1, r1, #3      ; Align source
+
+     MOV r12, r12, LSL #3    ; rshft = 0, *, 16 or 24 only
+
+     RSB r11, r12, #32       ; lshft = 32, 24, 16 or 8 only
+
+     LDR r0, [ r1 ], #4
+     MOV r0, r0, LSR r12 ; Always have r0 prepared
+
+; Quick sort out of what we've got left to do
+
+     SUBS r3, r3, #4 * 4       ; Four whole words to do (or more) ?
+     BLT MovByt240                   ; no
+
+     SUBS r3, r3, #8*4-4*4     ; Eight whole words to do (or more) ?
+     BLT MovByt230                   ; no
+
+
+
+MovByt225
+
+     LDMIA r1!, { r4 - r10, r14 } ; NB. Order !
+     ORR r0, r0, r4, LSL r11
+
+     MOV r4, r4, LSR r12
+     ORR r4, r4, r5, LSL r11
+
+     MOV r5, r5, LSR r12
+     ORR r5, r5, r6, LSL r11
+
+     MOV r6, r6, LSR r12
+     ORR r6, r6, r7, LSL r11
+
+     MOV r7, r7, LSR r12
+     ORR r7, r7, r8, LSL r11
+
+     MOV r8, r8, LSR r12
+     ORR r8, r8, r9, LSL r11
+
+     MOV r9, r9, LSR r12
+     ORR r9, r9, r10, LSL r11
+
+     MOV r10, r10, LSR r12
+     ORR r10, r10, r14, LSL r11
+
+     STMIA r2!, { r0, r4 - r10 }
+
+     MOV r0, r14, LSR r12          ; keep r0 prepared
+
+     SUBS r3, r3, #8 * 4
+     BGE MovByt225                            ; do another 8 words
+
+     CMP r3, #-8 * 4                       ; Quick test
+     GRABS   "r0-r11, pc", EQ
+
+
+MovByt230
+
+     ADDS r3, r3, #8*4 - 4*4             ; Four whole words to do ?
+     BLT MovByt240
+
+     LDMIA r1!, { r4 - r6, r14 } ; NB. Order !
+     ORR r0, r0, r4, LSL r11
+
+     MOV r4, r4, LSR r12
+     ORR r4, r4, r5, LSL r11
+
+     MOV r5, r5, LSR r12
+     ORR r5, r5, r6, LSL r11
+
+     MOV r6, r6, LSR r12
+     ORR r6, r6, r14, LSL r11
+
+     STMIA r2!, { r0, r4 - r6 }
+
+     GRABS   "r0-r11, pc", EQ
+
+     SUB r3, r3, #4*4
+     MOV r0, r14, LSR r12   ; keep r0 prepared
+
+
+MovByt240
+
+     ADDS r3, r3, #2*4           ; Two whole words to do ?
+     BLT MovByt250
+
+
+     LDMIA r1!, { r4, r14 } ; NB. Order !
+     ORR r0, r0, r4, LSL r11
+
+     MOV r4, r4, LSR r12
+     ORR r4, r4, r14, LSL r11
+
+     STMIA r2!, { r0, r4 }
+
+     GRABS   "r0-r11, pc", EQ
+
+
+     SUB r3, r3, #2*4
+     MOV r0, r14, LSR r12   ; keep r0 prepared
+
+
+MovByt250
+
+     ADDS r3, r3, #2*4 - 1*4     ; One whole word to go ?
+     BLT MovByt260
+
+     LDR r14, [ r1 ], #4
+     ORR r0, r0, r14, LSL r11
+
+     STR r0, [ r2 ], #4
+
+     GRABS   "r0-r11, pc", EQ
+
+     SUB r3, r3, #1*4
+     MOV r0, r14, LSR r12   ; keep r0 prepared
+
+
+MovByt260
+
+     ADDS r3, r3, #1*4 - 0*4
+     GRABS   "r0-r11, pc", EQ
+
+     LDR r14, [ r1 ]          ; store remaining 1..3 bytes
+     ORR r0, r0, r14, LSL r11
+
+
+MovByt270
+
+     STRB r0, [ r2 ], #1
+     MOV r0, r0, LSR #8
+     SUBS r3, r3, #1
+     BGT MovByt270
+
+     GRABS   "r0-r11, pc"
+
+
+
+ END

s/CD_Routs

+; Copyright 1996 Acorn Computers Ltd
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     http://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+;
+; -> CD_Routs
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+; This contains the general routines that all soft drivers may use (if they're lazy)
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+; Routines in here:
+;                  cd_checkdrive
+;                  cd_control
+;                  cd_converttolba
+;                  cd_converttomsf
+;                  cd_discused
+;                  cd_driveready
+;                  cd_drivestatus
+;                  cd_inquiry
+;                  cd_lasterror
+;                  cd_opendrawer
+;                  cd_prefetch
+;                  cd_readdata
+;                  cd_readuserdata
+;                  cd_reset
+;                  cd_seekto
+;                  cd_stopdisc
+;                  cd_version
+
+
+;-----------------------------------------------------------------------------------------------
+cd_version ROUT
+;
+; on entry:
+;          nothing needed
+; on exit:
+;          r0 -> version string ( word 0 = version number * 100, word 1 .. = null term. string )
+;
+;-----------------------------------------------------------------------------------------------
+
+ GRAB      "r0-r11, r14"
+ ADR       r0, VersionMessage
+ BICS      pc, r14, #Overflow_Flag
+
+VersionMessage DCD Version
+                 = "$VString", " CD_SWI control module by Eesox", 0
+ ALIGN
+
+;-----------------------------------------------------------------------------------------------
+cd_lasterror ROUT
+;
+; on entry:
+;          nothing needed
+; on exit:
+;          r0 = number of last error, or 0 if none
+;
+;-----------------------------------------------------------------------------------------------
+
+ GRAB      "r0-r11, r14"
+ LDR       r0, LastErrorNumber
+ BICS      pc, r14, #Overflow_Flag
+
+
+
+;-----------------------------------------------------------------------------------------------
+cd_prefetch ROUT
+;
+; on entry:
+;          r0 =   addressing mode
+;          r1 =   block number
+;          r7 ->  control block
+; on exit:
+;          if error then r0-> error block, else all regs preserved
+;
+;-----------------------------------------------------------------------------------------------
+ MOV       r2, #1
+ ADR       r3, buffer + 32
+ MOV       r4, #1      ; Allow to run on
+
+;-----------------------------------------------------------------------------------------------
+cd_readdata ROUT
+;
+; on entry:
+;          r0 =   addressing mode
+;          r1 =   block number
+;          r2 =   number of blocks
+;          r3 ->  where to put data
+;          r4 =   number of bytes from each block wanted
+;          r7 ->  control block
+;          r12 -> my workspace
+;          r13 -> full descending stack
+; on exit:
+;          if error then r0-> error block, else all regs preserved
+;
+;-----------------------------------------------------------------------------------------------
+
+; r8  = scsi device id
+; r9  = card number
+; r10 = lun
+
+ STASH     "r0-r4"
+
+ Debug "cd_readdata",NL
+
+01
+
+ LDMIA     r7, { r8, r9, r10 }
+
+
+ MUL       r4, r2, r4
+
+;---------------------
+; Set up the cdb block
+;---------------------
+ MOV       r5, #&28
+ ORR       r5, r5, r10, LSL #8+5
+ MOV       r6, r2, LSR #8         ; Number of blocks
+ MOV       r6, r6, LSL #24        ;
+ AND       r14, r2, #255          ;
+ ADR       r2, buffer
+ STMIA     r2, { r5, r6, r14 }
+
+
+
+; R0 = address mode, R1 = address, RETURNS R1 = address
+
+ BL        ConvertToLBA
+
+;------------------
+; put in start pos
+;------------------
+ STRVCB    r1, buffer + 5
+ MOVVC     r1, r1, LSR #8
+ STRVCB    r1, buffer + 4
+ MOVVC     r1, r1, LSR #8
+ STRVCB    r1, buffer + 3
+ MOVVC     r1, r1, LSR #8
+ STRVCB    r1, buffer + 2
+
+
+;--------------------
+; Do the SCSI command
+;--------------------
+ ORRVC     r0, r8, r9,  LSL #3                 ; card number
+ ORRVC     r0, r0, r10, LSL #5                 ; lun
+ ORRVC     r0, r0, #escapepolloff + readdata   ; prevent 'escape key'
+
+; r1 = size of cdb
+ MOVVC     r1, #10
+
+; r2 -> cdb
+
+; r3 -> put data here
+
+; r4 = number of bytes returned
+
+ MOVVC     r5, #0
+
+ MOVVC     r8, #1
+
+ SWIVC     XSCSI_Op
+
+ GRAB      "r1-r5"
+
+ GRABS     "r0-r11, pc", VC
+
+
+ LDR       r6, [ r0 ]
+
+
+;-----------------------------------------------
+; If the error is 'Busy' because playing audio
+; then StopDisc and try again
+;-----------------------------------------------
+ LDR       r14, =Busy
+ TEQ       r6, r14
+ STASH     "r1-r5", EQ
+ SWIEQ     XCD_StopDisc
+ LDMEQFD   r13, { r0 - r4 }
+ BEQ       %BT01
+
+;-----------------------------------------------
+; If the error is "Illegal Request", "DataProtect" or "Blank check"
+; THEN make it WrongDataMode
+;-----------------------------------------------
+ LDR       r14, =IllegalRequest
+ SUBS      r6, r6, r14
+ SUBNES    r6, r6, #(DataProtect - IllegalRequest)
+ SUBNES    r6, r6, #(BlankCheck  - DataProtect)
+ addr      r0, WrongDataMode, EQ
+;-----------------------------------------------
+ BEQ       error_handler_lookup
+ B         error_handler
+
+;-----------------------------------------------------------------------------------------------
+cd_seekto ROUT
+;
+; on entry:
+;          r0 =   addressing mode
+;          r1 =   block number
+; on exit:
+;          if error then r0-> error block, else all regs preserved
+;
+;-----------------------------------------------------------------------------------------------
+
+
+ STASH     "r0-r1"
+
+ Debug "cd_seekto",NL
+
+01
+
+ LDMIA     r7, { r8, r9, r10 }
+
+
+;---------------------
+; Set up the cdb block
+;---------------------
+ MOV       r4, #&2b
+ ORR       r4, r4, r10, LSL #8+5
+ MOV       r5, #0
+ MOV       r6, #0
+ ADR       r2, buffer
+ STMIA     r2, { r4, r5, r6 }
+
+
+
+; R0 = address mode, R1 = address, RETURNS R1 = address
+
+ BL        ConvertToLBA
+
+;------------------
+; put in start pos
+;------------------
+ STRVCB    r1, buffer + 5
+ MOVVC     r1, r1, LSR #8
+ STRVCB    r1, buffer + 4
+ MOVVC     r1, r1, LSR #8
+ STRVCB    r1, buffer + 3
+ MOVVC     r1, r1, LSR #8
+ STRVCB    r1, buffer + 2
+
+
+;--------------------
+; Do the SCSI command
+;--------------------
+ BLVC      space_saver
+
+; r1 = size of cdb
+ MOVVC     r1, #10
+
+; r2 -> cdb
+
+; r4 = number of bytes returned
+ MOVVC     r4, #0
+
+ SWIVC     XSCSI_Op
+
+ GRAB      "r1-r2"
+
+ GRABS     "r0-r11, pc", VC
+
+;-----------------------------------------------
+; If the error is 'Busy' because playing audio
+; then StopDisc and try again
+;-----------------------------------------------
+ LDR       r14, =Busy
+ LDR       r6, [ r0 ]
+ TEQ       r6, r14
+ STASH     "r1-r2", EQ
+ SWIEQ     XCD_StopDisc
+ LDMEQFD   r13, { r0 - r1 }
+ BEQ       %BT01
+
+;-----------------------------------------------
+
+ B         error_handler
+
+;-----------------------------------------------------------------------------------------------
+cd_inquiry ROUT
+;
+; on entry:
+;          r0 -> place to put the inquiry data
+;          r7 -> control block
+; on exit:
+;
+;-----------------------------------------------------------------------------------------------
+
+ Debug "cd_enquiry",NL
+
+; r3 -> store here
+ MOV       r6, r0
+
+ BL        space_saver
+
+ MOV       r3, r6
+
+;--------------------------------
+; SCSI Inquiry command
+;--------------------------------
+ ORR       r0, r0, #escapepolloff + readdata   ; prevent 'escape key'
+
+ ADR       r14, cdb_inquiry
+ LDMIA     r14, { r4, r5 }
+ ORR       r4, r4, r10, LSL #8+5
+ STMIA     r2, { r4, r5 }
+
+ MOV       r4, #36
+
+ MOV       r5, #0
+
+ SWI       XSCSI_Op
+
+ BVS       error_handler
+
+ GRABS     "r0-r11, pc"
+
+;-----------------------------------------------------------------------------------------------
+cd_discused ROUT
+;
+; on entry:
+;          r0 =  addressing mode that the disc length should be returned in
+;          r1 -> storage area to put data in
+;          r7 -> control block
+; on exit:
+;
+;-----------------------------------------------------------------------------------------------
+
+; r3 -> store here
+
+;--------------------------------
+; SCSI ReadCapacity command
+;--------------------------------
+
+ Debug "cd_discused",NL
+
+ BL        space_saver
+
+ ORR       r0, r0, #escapepolloff + readdata   ; prevent 'escape key'
+
+ MOV       r1, #10
+
+ MOV       r4, #&25
+ ORR       r4, r4, r10, LSL #8+5
+ MOV       r6, #0
+ STMIA     r2, { r4, r5, r6 }
+
+ ADR       r3, buffer + 12
+
+ MOV       r4, #8
+
+ SWI       XSCSI_Op
+
+ BVS       error_handler
+
+;----------------------------------------------
+; Convert the disc length into the correct mode
+;----------------------------------------------
+
+; get r0 and r1 original values
+ LDMFD     r13, { r0-r11, r14 }
+
+ ADR       r5, buffer + 12
+ LDMIA     r5, { r3, r6 }
+
+ MOV       r5, #255
+ ORR       r5, r5, r5, LSL #16
+
+ AND       r2, r5, r3, ROR #24         ; CHANGE REGISTER FROM MSB/LSB TO LSB/HSB
+ AND       r4, r5, r3
+ ORR       r2, r2, r4, ROR #8          ; R2 = number of blocks on a disc
+
+ AND       r7, r5, r6, ROR #24         ; CHANGE REGISTER FROM MSB/LSB TO LSB/HSB
+ AND       r4, r5, r6
+ ORR       r7, r7, r4, ROR#8           ; R7 = size of a block
+
+
+ STR       r7, [ r1, #4 ]
+
+; If not in mode 0 then convert to other
+ TEQ       r0, #LBAFormat
+ ADDNE     r2, r2, #( MaxNumberOfBlocks + 1 ) * 2 + 1     ; ie point to lead out address
+
+ TEQ       r0, #MSFFormat
+ STRNE     r2, [ r1 ]
+ GRABS     "r0-r11, pc", NE
+
+
+
+;------------------------
+; Convert from LBA to MSF
+;------------------------
+ MOV       r0, #LBAFormat
+ MOV       r3, r1
+ MOV       r1, r2
+
+ BL        ConvertToMSF
+
+ BVS       error_handler
+
+; save the important bits in the users area
+ STR       r1, [ r3 ]
+
+ GRABS     "r0-r11, pc"
+
+;-----------------------------------------------------------------------------------------------
+cd_driveready ROUT
+;
+; on entry:
+;          r7 -> control block
+; on exit:
+;          r0 = 0 if drive is OK, else r0 = 1
+;
+;-----------------------------------------------------------------------------------------------
+
+ Debug "cd_driveready",NL
+
+; r3 -> store here
+
+;--------------------------------
+; SCSI TestUnitReady command
+;--------------------------------
+ BL        space_saver
+
+ MOV       r4, r10, LSL #8+5
+ STMIA     r2, { r4, r5 }
+
+ MOV       r4, #8
+
+ SWI       XSCSI_Op
+
+ GRAB      "r0-r11, r14", VC
+ MOVVC     r0, #0
+ BICVCS    pc, r14, #Overflow_Flag
+
+;------------------------------------------
+; If UnitAttention then update disc changed
+;------------------------------------------
+ LDR       r1, [ r0 ]
+ LDR       r2, =UnitAttention
+ TEQ       r2, r1
+ LDRNE     r2, =CheckCondition
+ TEQNE     r2, r1
+ BEQ       error_handler
+
+;------------------------------------------
+ GRAB      "r0-r11, r14"
+ MOV       r0, #1
+ BICS      pc, r14, #Overflow_Flag
+
+;-----------------------------------------------------------------------------------------------
+cd_stopdisc ROUT
+;
+; on entry:
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;
+;-----------------------------------------------------------------------------------------------
+
+ Debug "cd_stopdisc",NL
+
+;--------------------------------
+; SCSI Stop disc command
+;--------------------------------
+ BL        space_saver
+
+ MOV       r4, #&1b
+ ORR       r4, r4, r10, LSL #8+5
+ STMIA     r2, { r4, r5 }
+
+ MOV       r4, #0
+
+ SWI       XSCSI_Op
+
+ BVS       error_handler
+
+ GRABS     "r0-r11, pc"
+
+
+;-----------------------------------------------------------------------------------------------
+cd_opendrawer ROUT
+;
+; on entry:
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;
+;-----------------------------------------------------------------------------------------------
+
+ Debug "cd_opendrawer",NL
+
+;--------------------------------
+; SCSI Start/Stop unit command
+;--------------------------------
+ BL        space_saver
+
+ MOV       r4, #&1b
+ ORR       r4, r4, r10, LSL #8+5
+ MOV       r14, #2
+ STMIA     r2, { r4, r14 }
+
+ MOV       r4, #8
+
+ SWI       XSCSI_Op
+
+ GRABS     "r0-r11, pc", VC
+
+;--------------------------------------------------
+; If Illegal Request then the drawer must be locked
+;--------------------------------------------------
+ LDR       r1, [ r0 ]
+ LDR       r2, =IllegalRequest
+ TEQ       r1, r2
+ addr      r0, DrawerLocked, EQ
+ BEQ       error_handler_lookup
+ B         error_handler
+
+;-----------------------------------------------------------------------------------------------
+cd_converttolba ROUT
+; on entry:
+;          r0 = address mode
+;          r1 = address
+; on exit:
+;          if oVerflow set then r0 -> error block
+;          r1 = new address
+;
+;-----------------------------------------------------------------------------------------------
+
+ BL        ConvertToLBA
+
+ BVS       error_handler
+
+ STR       r1, [ r13, #4 ]
+
+ GRABS     "r0-r11, pc"
+
+
+;-----------------------------------------------------------------------------------------------
+cd_converttomsf ROUT
+; on entry:
+;          r0 = address mode
+;          r1 = address
+; on exit:
+;          if oVerflow set then r0 -> error block
+;          r1 = new address
+;
+;-----------------------------------------------------------------------------------------------
+
+ BL        ConvertToMSF
+
+ BVS       error_handler
+
+ STR       r1, [ r13, #4 ]
+
+ GRABS     "r0-r11, pc"
+
+
+;-----------------------------------------------------------------------------------------------
+cd_drivestatus ROUT
+;
+; on entry:
+;          r7 -> control block
+; on exit:
+;          r0 = status { 1=OK, 2=BUSY, 4=NOTREADY, 8=UNAVAILABLE }
+;-----------------------------------------------------------------------------------------------
+
+ Debug "cd_drivestatus",NL
+
+; r3 -> store here
+
+;--------------------------------
+; SCSI TestUnitReady command
+;--------------------------------
+ BL        space_saver
+
+ MOV       r4, r10, LSL #8+5
+ STMIA     r2, { r4, r5 }
+
+ MOV       r4, #8
+
+ SWI       XSCSI_Op
+
+;---------------
+; Everything OK
+;---------------
+
+ GRAB      "r0-r11, r14", VC
+ MOVVC     r0, #1
+ BICVCS    pc, r14, #Overflow_Flag
+
+;---------------------
+; What error occured ?
+;---------------------
+ LDR       r1, [ r0 ]
+
+; Not ready
+ LDR       r14, =NotReady
+ SUBS      r14, r1, r14
+ SUBNES    r14, r14, #&201d0 - NotReady    ; Unknown error
+ GRAB      "r0-r11, r14", EQ
+ MOVEQ     r0, #4
+ BICEQS    pc, r14, #Overflow_Flag
+
+; Busy
+ LDR       r14, =Busy
+ TEQ       r1, r14
+ LDRNE     r14, =NoSense
+ TEQNE     r1, r14
+ GRAB      "r0-r11, r14", EQ
+ MOVEQ     r0, #2
+ BICEQS    pc, r14, #Overflow_Flag
+
+; No drive - unavailable
+ LDR       r14, =TimeoutSelection
+ TEQ       r1, r14
+ GRAB      "r0-r11, r14", EQ
+ MOVEQ     r0, #8
+ BICEQS    pc, r14, #Overflow_Flag
+
+;-----------------
+; Some other error
+;-----------------
+ B         error_handler
+
+
+;-----------------------------------------------------------------------------------------------
+cd_control ROUT
+;
+; on entry:
+;          r0 = 0, 1 or 2 to set the level of error response
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;-----------------------------------------------------------------------------------------------
+;--------------------
+; Only 0 to 2 allowed
+;--------------------
+ CMP       r0, #2
+ addr      r0, InvalidParameter, CS
+ BCS       error_handler_lookup
+
+ MOV       r2, r0
+
+ LDMIA     r7, { r1, r3, r8 }
+ ORR       r1, r1, r3, LSL #3
+ ORR       r1, r1, r8, LSL #5
+
+ MOV       r0, #4
+ MOV       r8, #accesskey
+ SWI       XSCSI_Control
+
+ BVS       error_handler
+
+ GRABS     "r0-r11, pc"
+
+
+;-----------------------------------------------------------------------------------------------
+cd_reset ROUT
+;
+; on entry:
+;          r7 ->  control block
+; on exit:
+;          if error then r0-> error block, else all regs preserved
+;
+;-----------------------------------------------------------------------------------------------
+
+ LDMIA     r7, { r1, r2, r3 }
+
+ ORR       r1, r1, r2, LSL #3
+ ORR       r1, r1, r3, LSL #5
+
+ MOV       r0, #1
+
+ MOV       r8, #1
+
+ SWI       XSCSI_Initialise
+
+ BVS       error_handler
+
+ GRABS     "r0-r11, pc"
+
+
+;-----------------------------------------------------------------------------------------------
+cd_checkdrive ROUT
+;
+; on entry:
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;          r0 = drive status bits
+;-----------------------------------------------------------------------------------------------
+
+ Debug "cd_checkdrive",NL
+
+;--------------------------------
+; SCSI SendDiagnostics command
+;--------------------------------
+ BL        space_saver
+
+ MOV       r4, #&1d
+ ORR       r4, r4, r10, LSL #8+5
+ ORR       r4, r4, #1:SHL:10
+ STMIA     r2, { r4, r5 }
+
+ MOV       r4, #0
+
+ SWI       XSCSI_Op
+
+;-------------------------
+; Is it a hardware error ?
+;-------------------------
+ TEQVC     r0, r0
+ LDRVS     r1, [ r0 ]
+ LDRVS     r2, =HardwareError
+ TEQVS     r1, r2
+
+ BNE       error_handler     ; [ no ]
+
+;-------------------------
+
+ GRAB      "r0-r11, r14"
+
+ MOVVC     r0, #0
+ MOVVS     r0, #15
+
+ BICS      pc, r14, #Overflow_Flag
+
+;-----------------------------------------------------------------------------------------------
+cd_readuserdata ROUT
+;
+; The purpose of this call: is to load just user data from mode 2 form 1 or 2 blocks.  This
+; part will also work out if it is possible to use a 'complex' scatter list method to improve
+; performance.
+;
+; on entry:
+;          r0 =  addressing mode (0, 1 or 2)
+;          r1 =  start block
+;          r2 =  number of bytes to load (also indicates size of 'r3' buffer)
+;          r3 -> put data here
+;          r4 =  byte offset in start block to start from
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;          r1 =  last block loaded
+;          r4 =  byte offset in last block of next byte
+;-----------------------------------------------------------------------------------------------
+
+;---------------------------------------------
+; Does this SCSI card support scatter lists ?
+;---------------------------------------------
+
+ B         cd_readuserdata_plain
+
+;---------------------------------------------
+; Convert block to logical block address
+;---------------------------------------------
+
+; BL        ConvertToLBA
+; BVS       error_handler
+
+;-----------------------------------------------------------------------------------------------
+cd_readuserdata_plain ROUT
+;
+; The purpose of this call: is to load just user data from mode 2 form 1 or 2 blocks.  This
+; 'plain' method will use normal CD_ReadData commands.  SCSI and non-SCSI drives should work
+; this way.
+;
+; on entry:
+;          r0 =  addressing mode
+;          r1 =  start block
+;          r2 =  number of bytes to load (also indicates size of 'r3' buffer)
+;          r3 -> put data here
+;          r4 =  byte offset in start block to start from
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;          r1 =  last block loaded
+;          r4 =  byte offset in last block of next byte
+;-----------------------------------------------------------------------------------------------
+
+;---------------------------------------------
+; Convert block to logical block address
+;---------------------------------------------
+
+ BL        ConvertToLBA
+ BVS       error_handler
+
+
+
+ [ debug=ON
+ Debug     "StartBlock = &"
+ MOV       r6, r1
+ DebugDisplay r6
+ SWI XOS_NewLine
+ Debug     "StartByte = &"
+ DebugDisplay r4
+ SWI XOS_NewLine
+ Debug     "NBytes = &"
+ DebugDisplay r2
+ SWI XOS_NewLine
+ ]
+
+
+ MOV       r6, r4
+ MOV       r4, r1
+ MOV       r5, r3
+
+; r0 =
+; r1 =
+; r2 =  number of bytes to load
+; r3 =
+; r4 =  block
+; r5 -> memory
+; r6 =  byte offset in first block
+; r7 -> control block
+
+
+; Alogorithm:
+;            REPEAT
+;                work out number of blocks that can be loaded
+;                load the number of blocks
+;                shuffle blocks
+;            UNTIL <= 1 block left to load
+;
+;            Load last block into my buffer
+;            Copy out last bytes
+
+
+RUDP_Repeat
+;----------------------
+;            REPEAT
+;----------------------
+
+;------------------------------------------------------------------
+;                work out number of bytes storage space available
+;------------------------------------------------------------------
+ MOV       r10, r2
+
+;------------------------------------------------------------------
+;                work out number of blocks that can be loaded
+;------------------------------------------------------------------
+ LDR       r9, =mode2datasize
+ DivRem    r8, r10, r9, r14
+
+ TEQ       r8, # 0
+ BEQ       RUDP_LastBlock
+
+;------------------------------------------------------------------
+;                load the number of blocks
+;------------------------------------------------------------------
+
+;          r0 =   addressing mode
+;          r1 =   block number
+;          r2 =   number of blocks
+;          r3 ->  where to put data
+;          r4 =   number of bytes from each block wanted
+;          r7 ->  control block
+
+ STASH     "r1 - r5"
+
+ MOV       r0, # LBAFormat
+ MOV       r1, r4
+ MOV       r2, r8
+ MOV       r3, r5
+ LDR       r4, =mode2datasize
+
+ SWI       XCD_ReadData
+
+ GRAB      "r1 - r5"
+
+ BVS       error_handler
+
+;------------------------------------------------------------------
+;                shuffle blocks
+;------------------------------------------------------------------
+
+; r0  =
+; r1  =  memory to copy from
+; r2  =  memory to copy to
+; r3  =  USERDATA_MODE2FORM2
+; r4  =  block
+; r5  -> memory to copy to
+; r6  =  number of blocks left to shuffle
+; r7  -> control block
+; r8  =  mode2datasize
+; r9  =  number of bytes loaded
+; r10 =  byte offset in first block
+
+ STASH     "r0-r4, r6-r8, r10"
+
+ MOV       r10, r6
+ MOV       r6, r8
+
+ LDR       r8, =mode2datasize
+
+ ADD       r1, r5, # MODE2__TOTALHEADERSIZE
+ ADD       r1, r1, r10
+ MOV       r2, r5
+
+ MOV       r9, # 0
+
+RUDP_ShuffleBlocks
+
+ MOV       r4, # USERDATA__MODE2FORM1
+
+; Is the data in mode 2 form 2 ?
+ SUB       r14, r1, r10
+ LDRB      r14, [ r14, # (MODE2__HEADER_SIZE + MODE2__SUB_HEADER_SUBMODE) - MODE2__TOTALHEADERSIZE ]
+ TST       r14, # SUBMODE__FORM
+ ADDNE     r4, r4, # USERDATA__MODE2FORM2 - USERDATA__MODE2FORM1
+
+
+
+ SUB       r3, r4, r10
+
+ BL        cd_bytecopyinternal
+
+ ADD       r1, r1, r8
+ SUB       r1, r1, r10
+
+ ADD       r2, r2, r3
+
+
+; count number of bytes copied
+ ADD       r9, r9, r3
+
+ MOV       r10, # 0
+
+ SUBS      r6, r6, # 1
+ BGT       RUDP_ShuffleBlocks
+
+ MOV       r5, r2
+
+ GRAB      "r0-r4, r6-r8, r10"
+
+ MOV       r6, # 0
+
+; r0 =  drive number
+; r1 =
+; r2 =  number of blocks
+; r3 =
+; r4 =  block
+; r5 -> memory
+; r6 =  byte offset in block to start from (0 at the moment)
+; r7 -> control block
+
+
+ Debug " CopiedLots = &"
+ DebugDisplay r9
+
+
+ ADD       r4, r4, r8
+ SUB       r2, r2, r9
+
+;------------------------------------------------------------------
+;            UNTIL <= 1 block left to load
+;------------------------------------------------------------------
+
+ LDR       r14, =mode2datasize
+ CMP       r2, r14
+ BGT       RUDP_Repeat
+
+;------------------------------------------------------------------
+;            Load last block into my buffer
+;------------------------------------------------------------------
+RUDP_LastBlock
+
+;------------------------------------------------------------------
+;            Copy out last bytes
+;------------------------------------------------------------------
+
+ STASH     "r0-r4"
+
+ CLV
+
+ MOVS      r9, r2
+
+ MOV       r0, # LBAFormat
+ MOV       r1, r4
+ MOV       r2, # 1
+ ADR       r3, buffer
+ LDR       r4, =mode2datasize
+
+;          r0 =   addressing mode
+;          r1 =   block number
+;          r2 =   number of blocks
+;          r3 ->  where to put data
+;          r4 =   number of bytes from each block wanted
+;          r7 ->  control block
+
+ SWIGT     XCD_ReadData
+ BVS       error_handler
+
+; r1 =  memory to copy from (buffer + 12 + byte offset)
+ ADR       r1, buffer + MODE2__TOTALHEADERSIZE
+
+; r2 =  memory to copy to
+ MOV       r2, r5
+
+
+
+ MOV       r14, # USERDATA__MODE2FORM1
+
+; Is the data in mode 2 form 2 ?
+ LDRB      r3, [ r1, # (MODE2__HEADER_SIZE + MODE2__SUB_HEADER_SUBMODE) - MODE2__TOTALHEADERSIZE ]
+ TST       r3, # SUBMODE__FORM
+ ADDNE     r14, r14, # USERDATA__MODE2FORM2 - USERDATA__MODE2FORM1
+
+
+
+
+ SUB       r14, r14, r6
+
+ ADD       r1, r1, r6
+
+ CMP       r9, r14
+ MOVGT     r9, r14
+
+; r3 =  2324 - byte offset, or bytes left to copy, whichever is smaller
+ MOVS      r3, r9
+
+ ADD       r5, r5, r3
+
+ BLGT      cd_bytecopyinternal
+
+ GRAB      "r0-r4"
+
+
+ SUBS      r2, r2, r9
+ MOVGT     r6, # 0
+ ADDGT     r4, r4, # 1
+ BGT       RUDP_LastBlock
+
+
+; return values
+;          r1 =  last block loaded
+;          r4 =  byte offset in last block of next byte
+
+ ADDS      r9, r9, r6
+
+ LDR       r14, =USERDATA__MODE2FORM2
+
+ MOVEQ     r9, r14
+
+ CMP       r9, r14
+ MOVGE     r9, # 0
+ ADDGE     r4, r4, # 1
+ ADDLT     r9, r9, # 1
+ STR       r9, [ r13, # 4*4 ]
+ STR       r4, [ r13, # 4*1 ]
+
+
+ [ debug=ON
+ SWI XOS_NewLine
+ SWI XOS_NewLine
+ ]
+
+
+ GRAB      "r0-r11, r14"
+ BICS      pc, r14, #Overflow_Flag
+
+
+
+;-----------------------------------------------------------------------------------------------
+cd_seekuserdata ROUT
+;
+; The purpose of this call is to find where a particular byte of user data starts in a
+; consecutive number of mode 2 form 1 or 2 blocks.  The drive is not expected to seek or load
+; any information, just report at what block, and what offset the byte occurs.  This will try
+; to use a SCSI scatter list to improve performance.
+;
+; on entry:
+;          r0 =  addressing mode (0, 1 or 2)
+;          r1 =  start block (starting from byte 0 of this block)
+;          r2 =  byte offset to search for (first position is 0)
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;          r1 =  block found at (in addressing mode of r0 on entry)
+;          r2 =  byte offset in block
+; all other registers preserved
+;-----------------------------------------------------------------------------------------------
+
+;---------------------------------------------
+; Does this SCSI card support scatter lists ?
+;---------------------------------------------
+
+ B         cd_seekuserdata_plain
+
+;---------------------------------------------
+; Convert block to logical block address
+;---------------------------------------------
+
+; BL        ConvertToLBA
+; BVS       error_handler
+
+;-----------------------------------------------------------------------------------------------
+cd_seekuserdata_plain ROUT
+;
+; The purpose of this call is to find where a particular byte of user data starts in a
+; consecutive number of mode 2 form 1 or 2 blocks.  The drive is not expected to seek or load
+; any information, just report at what block, and what offset the byte occurs.  Being 'plain'
+; it has to make do with current CD_ SWIs so that SCSI and non-SCSI commands work.
+;
+; on entry:
+;          r0 =  addressing mode (0, 1 or 2)
+;          r1 =  start block (starting from byte 0 of this block)
+;          r2 =  byte offset to search for (first position is 0)
+;          r7 -> control block
+; on exit:
+;          usual error stuff
+;          r1 =  block found at (in addressing mode of r0 on entry)
+;          r2 =  byte offset in block
+; all other registers preserved
+;-----------------------------------------------------------------------------------------------
+
+;---------------------------------------------
+; Convert block to logical block address
+;---------------------------------------------
+
+ BL        ConvertToLBA
+ BVS       error_handler
+
+
+;-------------------------------------------------------------------
+; Byte offset of less than 2048 means it must be in the first block
+;-------------------------------------------------------------------
+ CMP       r2, # USERDATA__MODE2FORM1
+ GRAB      "r0-r11, r14", LT
+ BICLTS    pc, r14, #Overflow_Flag
+
+
+;---------------------------------------------
+; Assume mode 2 form 2 ?
+;---------------------------------------------
+
+ LDR       r3, =USERDATA__MODE2FORM2
+ DivRem    r4, r2, r3, r14
+
+ ADD       r1, r1, r4
+
+; r0 = addressing format
+; r1 = block
+; r2 = byte offset
+
+ TEQ       r0, # MSFFormat
+ MOVEQ     r0, # LBAFormat
+ BLEQ      ConvertToMSF
+
+ TEQ       r0, # PBFormat
+ ADDEQ     r1, r1, # 75*2
+
+ STR       r1, [ r13, # 4*1 ]
+ STR       r2, [ r13, # 4*2 ]
+
+ GRAB      "r0-r11, r14"
+ BICS      pc, r14, #Overflow_Flag
+
+
+
+;-----------------------------------------------------------------------------------------------
+; Routine to load default values and save space
+;-----------------------------------------------------------------------------------------------
+space_saver ROUT
+ LDMIA     r7, { r8, r9, r10 }
+
+ ORR       r0, r8, r9,  LSL #3                 ; card number
+ ORR       r0, r0, r10, LSL #5                 ; lun
+ ORR       r0, r0, #escapepolloff + nodata     ; prevent 'escape key'
+ MOV       r1, #6
+ ADR       r2, buffer
+ MOV       r3, #0
+ MOV       r5, #0
+ MOV       r8, #1
+
+ MOV       pc, r14
+
+
+
+
+
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+;-----------------------------------------------------------------------------------------------
+
+
+
+
+
+ END

s/ExtraBits

+; Copyright 1996 Acorn Computers Ltd
+;
+; Licensed under the Apache License, Version 2.0 (the "License");
+; you may not use this file except in compliance with the License.
+; You may obtain a copy of the License at
+;
+;     http://www.apache.org/licenses/LICENSE-2.0
+;
+; Unless required by applicable law or agreed to in writing, software
+; distributed under the License is distributed on an "AS IS" BASIS,
+; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+; See the License for the specific language governing permissions and
+; limitations under the License.
+;
+;----------------------------------------------------------------------------------------------
+;                Convert addressing modes
+;----------------------------------------------------------------------------------------------
+
+; IF addressmode = LBAFormat THEN EXIT ( already done )
+
+; IF addressmode = PBFormat THEN address = address - 2 seconds of data
+
+; IF addressmode = MSFFormat THEN change address to minute,second,frame
+
+;----------------------------------------------------------------------------------------------
+
+
+;----------------------------------------------------------------------------------------------
+ConvertToLBA ROUT
+; on entry:
+;          r0 = address mode
+;          r1 = address
+; on exit:
+;          if oVerflow set then r0 -> error block
+;          r1 = new address
+;
+; Errors can occur, eg/ invalid mode number
+; When this is called, 'address' should contain the address on the disc
+; in whatever format is being used.  'addressmode' should contain the number
+; of the type of addressing being used.  Eg LBAFormat, MSFFormat, PBFormat
+;
+;----------------------------------------------------------------------------------------------
+
+ BIC       r14, r14, #Overflow_Flag
+;--------------------------------------------------
+; If already in LBA format then exit straight away
+;--------------------------------------------------
+
+ TEQ       r0, #LBAFormat
+ MOVEQS    pc, r14
+
+ STASH     "r0, r2 - r5, r14"
+
+;--------------------------------------------------
+; Check for allowable addressing mode
+;--------------------------------------------------
+ CMP       r0, #3
+ GRAB      "r0, r2 - r5, r14", CS
+ addr      r0, InvalidFormat, CS
+ ORRCSS    pc, r14, #Overflow_Flag
+
+;--------------------------------------------------
+; Branch to routines to convert from each mode to LBA
+;--------------------------------------------------
+; R0 = address mode
+; R1 = address
+
+ TEQ       r0, #1
+ BEQ       ChangeFromMSFFormat
+
+;--------------------------------------------------
+;  Change from Physical Block TO Logical Block Address
+;  Subtract 2 seconds worth of blocks to give LBA
+;--------------------------------------------------
+
+ChangeFromPBFormat
+
+ SUBS      r1, r1, #( MaxNumberOfBlocks + 1 ) * 2
+
+ GRAB      "r0, r2 - r5, r14", LT
+ addr      r0, PhysicalBlockError, LT
+ ORRLTS    pc, r14, #Overflow_Flag
+
+
+ GRABS     "r0, r2 - r5, pc"
+
+
+;----------------------------------------------------------------------------------------------
+;    Change Minutes, Seconds, Frame TO LBA
+ChangeFromMSFFormat    ; R1 = address, RETURNS R1 = address
+;----------------------------------------------------------------------------------------------
+
+; R1 = address
+
+;-----------------------------------------
+; R3 = frames
+;-----------------------------------------
+ MOV       r14, #255
+ AND       r3, r1, r14
+
+;-----------------------------------------
+; R4 = seconds
+;-----------------------------------------
+ AND       r4, r14, r1, LSR #8
+
+;-----------------------------------------
+; R5 = minutes
+;-----------------------------------------
+
+ AND       r5, r14, r1, LSR #16
+
+;-----------------------------------------
+; Make sure that seconds are ( 0 - 59 )
+;-----------------------------------------
+
+ CMP       r4, #MaxNumberOfSeconds + 1
+ GRAB      "r0, r2 - r5, r14", CS
+ addr      r0, BadSeconds, CS
+ ORRCSS    pc, r14, #Overflow_Flag
+
+;-----------------------------------------
+; Make sure that frames are ( 0 - 74 )
+;-----------------------------------------
+
+ CMP       r3, #MaxNumberOfBlocks + 1
+ GRAB      "r0, r2 - r5, r14", CS
+ addr      r0, BadBlocks, CS
+ ORRCSS    pc, r14, #Overflow_Flag
+
+;-----------------------------------------
+; minutes = minutes * 60 + seconds
+;-----------------------------------------
+
+ MOV       r14, r5, LSL #6                     ; R14 = minutes * 64
+ SUB       r5, r14, r5, LSL #2                 ; R5 = R14 - ( minutes * 4 )
+ ADD       r5, r5, r4
+
+;-----------------------------------------
+; minutes = minutes * 75 + blocks
+;-----------------------------------------
+ MOV       r14, #MaxNumberOfBlocks + 1
+ MLA       r5, r14, r5, r3
+
+;-----------------------------------------
+; minutes = minutes - 2 seconds
+;-----------------------------------------
+ SUB       r1, r5, #( MaxNumberOfBlocks + 1 ) * 2
+
+;-----------------------------------------
+
+ GRABS      "r0, r2 - r5, pc"
+
+
+;----------------------------------------------------------------------------------------------
+ConvertToMSF ROUT
+;                             Convert from LBA or PB to MSF format
+; IF addressmode = MSFFormat THEN EXIT ( already done )
+;
+; IF addressmode = LBAFormat THEN ...
+;
+;
+; on entry:
+;          r0 = address mode
+;          r1 = address
+;
+; on exit:
+;          if oVerflow clear THEN r1 = new address ELSE r0->error block
+;
+; flags preserved
+;----------------------------------------------------------------------------------------------
+
+ BIC        r14, r14, #Overflow_Flag
+
+;-----------------------------------------
+; If already in MSF format then exit straight away
+;-----------------------------------------
+
+ TEQ        r0, #MSFFormat
+ MOVEQS     pc, r14
+
+ STASH      "r0, r2 - r5, r14"
+
+
+;-----------------------------------------
+; Check for allowable addressing mode
+;-----------------------------------------
+
+ CMP        r0, #3
+ GRAB       "r0, r2 - r5, r14", CS
+ addr       r0, InvalidFormat, CS
+ ORRCSS     pc, r14, #Overflow_Flag
+
+;-----------------------------------------
+; Branch to routines to convert from each mode to MSF
+;-----------------------------------------
+; r0 = address mode
+; r1 = address
+
+ TEQ        r0, #0
+ BEQ        ConvertLBAtoMSF
+
+;-----------------------------------------
+ConvertPBtoMSF
+; R1 = address
+;-----------------------------------------
+; address = address - 150 ( error if < 0 )
+
+ SUBS       r1, r1, #( MaxNumberOfBlocks + 1 ) * 2
+ GRAB       "r0, r2 - r5, r14", LT
+ addr       r0, BadSeconds, LT
+ ORRLTS     pc, r14, #Overflow_Flag
+
+;-----------------------------------------
+ConvertLBAtoMSF
+; R1 = address
+;-----------------------------------------
+; R3 = Frames
+; R4 = seconds
+; R5 = minutes
+
+
+;-----------------------------------------
+; Frame = address MOD ( MaxNumberOfBlocks + 1 )
+; R3 = R3 MOD ( MaxNumberOfBlocks + 1 )
+;-----------------------------------------
+
+
+;-----------------------------------------
+; Seconds = ( address DIV 75 ) MOD 60
+; R4
+;-----------------------------------------
+
+ MOV        r3, r1                                    ; r2 = address DIV 75
+                                                      ;
+ DivRem     r2, r3, #MaxNumberOfBlocks + 1, r14       ; r3 = address MOD 75
+
+ DivRem     r4, r2, #MaxNumberOfSeconds + 1, r14      ; r4 = r2 DIV 60
+                                                      ;
+                                                      ; r2 = r2 MOD 60
+
+; R4 = minutes
+; R3 = frames
+; R2 = seconds
+
+;-----------------------------------------
+; Push results together into one word
+; Minutes << 16 + Seconds << 8 + Frames
+;-----------------------------------------
+ ORR        r3, r3, r2, LSL #8
+ ORR        r1, r3, r4, LSL #16
+
+ GRABS      "r0, r2 - r5, pc"
+
+
+;----------------------------------------------------------------------------------------------
+;----------------------------------------------------------------------------------------------
+;----------------------------------------------------------------------------------------------
+;----------------------------------------------------------------------------------------------
+;----------------------------------------------------------------------------------------------
+
+ END