I was just looking at the DOVE MacSnap SCSI adapter board I have. From a design perspective it looks exactly like the John Bass schematics, though with a few more resisters and capacitors as well as terminators. Obviously the Bass design is for use with a single hard drive and no pass through or daisy chaining.
However, what interested me the most, is that the Dove board uses the same 5380 SCSI chip and two EP320PC-2 chips. The differences between the EP320PC2 and the 74LS10 escape me and the internet was not much help, but it strikes me as more than coincidence that the designs are otherwise so symmetrical.
The Dove requires 128K ROMs, which suggests that it relies on the SCSI software and drivers within the ROMs to access the drives on the bus. John Bass' design seems to add the proper software to the System file on the startup disk. Therefore, it seems as though the Dove board might work perfectly well with the 64K ROMs as long as the drivers and formatting software are present in the System file. The Dove boards turn up routinely on eBay and if this hack were so, it would eliminate the need to build these interfaces. However, the most difficult part is still going to be to adapt this driver at a minimum to a modern SCSI drive.
However, what interested me the most, is that the Dove board uses the same 5380 SCSI chip and two EP320PC-2 chips. The differences between the EP320PC2 and the 74LS10 escape me and the internet was not much help, but it strikes me as more than coincidence that the designs are otherwise so symmetrical.
The Dove requires 128K ROMs, which suggests that it relies on the SCSI software and drivers within the ROMs to access the drives on the bus. John Bass' design seems to add the proper software to the System file on the startup disk. Therefore, it seems as though the Dove board might work perfectly well with the 64K ROMs as long as the drivers and formatting software are present in the System file. The Dove boards turn up routinely on eBay and if this hack were so, it would eliminate the need to build these interfaces. However, the most difficult part is still going to be to adapt this driver at a minimum to a modern SCSI drive.