On 4/23/22 07:16, Liam Proven wrote: > On Fri, 22 Apr 2022 at 23:41, Chuck Guzis <[email protected]> wrote: >> >> Take a look at the chip (DP8473) datasheet. It boasts direct (no >> buffer needed) support of up to 4 drives. The rest is software; the >> protocol is pretty much write some registers before/after >> writing/reading to the buffer memory. In other words, it's a low-level >> interface protocol; there's really no intelligence in the unit. > > TBH, I wouldn't know. I'm a software type at best. Interesting info, though!
An interesting aside is that on Adaptec and Future Domain SCSI ISA cards with the NS chip, it's quite possible to run an additional wire between the chip and the floppy header and get 3 floppies on a single cable. DTC and Ultrastor used the "twisty twisty" cable on their cards to do the same. There also was a DTC (ESDI or SCSI, I don't recall) ISA card that, with a jumper allowed one to run 4 floppies on single "flat" ribbon cable. Each drive had its own drive select (0,1,2,3) and all drive motors ran at the same time, but it worked. --Chuck
