On Wed, Sep 23, 2020 at 11:51 AM Michael Engel via cctech <cct...@classiccmp.org> wrote: > > Hi, > > still working on backing up the Tektronix 440x disks. My current problem > is that the ACB4000 SCSI-to-MFM adapter doesn´t support SCSI parity. > > I finally managed to find a PCI SCSI controller (Adaptec 2940) and a > Pentium 4 PC with PCI slots and installed OpenBSD 6.7. I disabled parity > checking in the Adaptec BIOS config and it detects a disk at ID 0 with > no name. So far, so good. >
If the Adaptec 2940 BIOS seems to detect the disk I wonder what would happen if DOS was set up on the system and ASPI8DOS.SYS was loaded. Would the Adaptec 2940 and ASPI driver respect the BIOS parity setting and interact with the ACB4000 bridge well enough for a fairly simple DOS program to be able to use the ASPI interface to send READ CDBs to read the sectors from the device? If I had such a device myself to experiment with I'd probably give that a try to see if it works.