Disabling SCSI parity checking to dump disk on ACB4000 MFM-SCSI adapter?

Yes, the ACB-4000 doesn?t play well with anything modern. The SPU (service processor) disk on my Convex C-1 uses a Fujitsu MFM disk with an ACB-4000. I absolutely had to save the contents of that disk, so here is my approach: I used an Ancot Ultra2080/Lite SCSI-bus Analyzer. This is a device that connects to a SCSI bus and has a serial port. Over the serial port, you can monitor the signals on the SCSI bus, and use it as a SCSI protocol analyzer. There?s also the possibility to construct and send a SCSI command. Rather than connect a serial terminal to the serial port, I connected a PC, then wrote a C program to control the Ancot. I had the Ancot send commands to the disk to read a sector at a time, and recorded the data sent in response to a file to create a disk image. Slow as hell (each byte on the disk requires sending two hex characters and a space over a slow serial line), but it works. I had to make several passes over the disk, because occasionally the data received from the disk turned out to be data from a different sector than the one I was trying to read. By reading the disk multiple times, I could get rid of these mis-read sectors. I put the image created this way on a new disk (well, an old DEC 1GB disk with a SCSI-1 mode jumper) and was able to boot the SPU from this disk (It could not boot off the original disk), and later replaced it with a SCSI2SD. If you?re interested, and have access to an Ancot, I can probably dig out the C code I wrote. Camiel