OK I've squashed the bug, it was stack corruption. Release attached to the post. To the best of my knowledge this version is working, but PLEASE do not use this driver to try to read irreplaceable disks without write-protecting them. If you do you are bad and should feel bad.
DEVICE=DOSFDRV.SYS /U:unit [/D:type] [/P
ort] [/SC]
Where "unit" is a physical unit number (0-3) and "type" is a DOS floppy type. If no type is specified, the profile defined at build time will be used. In this build, that is a standard 40 track DSDD 5.25" disk, but it is there to give me the ability to easily make custom builds for odd disks. Type 3 refers to a MSDOS formatted SSSD 8" disk. Type 4 is 8" DSDD but is disabled until I get blocking/deblocking implemented. With type 3/4, an optional "/SC" may be added to have the driver use the original SCP 86-DOS format. "/P
ort" is optional and specifies the hex address of the controller to be used.
The other valid types are:
0 360kB DSDD 5.25"
1 1.2MB DSHD 5.25"
2 720kB DSDD 3.5"
7 1.44MB DSHD 3.5"
9 2.88MB DSED 3.5" (untested, I don't have any drives or media)
If you make an error in the switches, the driver will not load and will pause the system, beep at you and remind you the correct syntax. If you specify a drive on a secondary FDC, the driver will reset said FDC and attempt to seek the unit specified to track 0 at initialization. If this fails, (due to incorrect unit number, drive not attached, etc.) the driver will not load and will pause the system with an error message. Formatting IS implemented, but may be buggy. Needless to say, IBM-compatible MSDOS FORMAT.COM is not going to write out boot sectors compatible with SCP S-100 machines. The disks will be accessible for R/W operations on original hardware, just not bootable.
One more thing - there is no support implemented in this release for using disks smaller than the profile associated with the device type. I.e 720kB disk in HD 3.5" drive, 360kb disk in 1.2MB HD drive, or 160kb/180kB/320kB disks in anything.