On Monday, May 8, 2023 at 6:56:33 PM UTC-4 Mac Doktor wrote: I recall reading on multiple occasions that a SCSI driver was a non-trivial exercise. Sort-of like "if you don't appreciate how non-trivial it is don't even bother".
Yup. It was bad enough when there was an actual controller chip, but at least the chip handled some of the handshaking internally. Doing it with parallel ports alone was *quite* exciting. Fortunately the original design only needed* to support the Xebec S1410 SASI/ST-506 bridge. Even that was fraught with peril - the SyQuest SQ306 drive used a servo "wedge", so an incautious format operation would destroy** the cartridge servo information and render the cartridge unusable. To make matters worse, the field test drives had matching cartridges - interchange between drives didn't yet work. Ah, the bad old days... * Of course, right after release a customer showed up wanting to use a tape drive ** Xebec eventually released a new S1410 firmware EPROM that prevented this - if you happened to have a controller with that EPROM (it wasn't the default) My company had lots of experience with oddball storage - we had a Vertimag 5MB(ish) floppy disk prototype. And I was involved with the Evotek ET-5540 disk drive. That was "interesting", but that's a story for another time. We eventually went with CDC Wren drives. DEC (Evotek's other large OEM customer) had a bit more inertia and had to scramble for available drives - that's why the DEC RD52 might be a Quantum Q540 (more common) or an Atasi 3046 (rather rare). -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/6862d798-a2b9-486a-ba29-9d68fb21235dn%40googlegroups.com.
