GitLab

Reorder the open pipe special fields to match those in the USB driver to side step the DeviceFS parsing problem prior to DeviceFS-0_69
Make the upcall handler robust to device streams being shut, see
  http://www.riscosopen.org/forum/forums/3/topics/1970
for the gritty details.

Version 0.18. Tagged as 'SCSISoftUSB-0_18'