26-bit Shared C library (ROM or RAM): ARM 2 or later (26-bit) Will always be in 26-bit modes Client may be APCS-32 or APCS-R 26-bit ANSILib ARM 2 or later (26-bit) Will always be in 26-bit modes Client is APCS-R 32-bit Shared C library (ROM or RAM): ARM 6 or later (32-bit) May be in 26 or 32-bit modes 32-bit instructions always available Client is APCS-32 32-bit ANSILib ARM 6 or later May be in 26 or 32-bit modes 32-bit instructions always available Client is APCS-32 32-bit ANSILib will be RISC OS 3.5 or later other requirements for any CLib or ANSILib: RISC OS 3.1 FPEmulator 4.03 or later CallASWI (if RISC OS 3.6 or earlier)