Big wrote:
Cool thanks. I'm on the lookout for dead Mac SEs and the like... It appears you're right - the IWM chip in the IIc+ should be able to recognize the Apple 800 K drive. But will the 800 K drive recognize disks, read from and write to disks created on the original IIc+ UniDisk drive?
The built-in drive in the IIc+ isn't a UniDisk. UniDisks are external drives that have a 65C02 on the daisychain board. The reason given was because the 1mhz Apple IIs were considered too slow to handle the 3.5" drive. In theory the drive in the IIc+ should be faster than the 3.5" UniDisks because the UniDisks use a 4:1 interleave while the IIc+ can happily use a 2:1 interleave. One problem though, most 8 bit software formats 4:1. Some will recognize being run on a IIgs and format 2:1 but on an 8 bit Apple II format 4:1 no matter what interleave your floppy drive will handle. In any case all the Apple made 800k drives use the same mechanism. Wayne