It's been a while so my memory may be fuzzy, but I got my first Mac at work in Nov '83, and bought my own Mac in May '84. A bit later Apple came out with the first 3.5" Apple][ drive which is 800K with a built-in 6502 of its own. Removing the Apple][ controller card left a drive which could be plugged into a Mac, and which the Mac (64K ROM) recognized as a double-sided disk and formatted MFS 800K. There really wasn't anything more to it than that.
Well I appreciate that, but your memory is extremely fuzzy. ;-) If you got a 128K Mac in Nov. '83, that was 3 months before anybody else in the world got one (unless you worked for the Apple Macintosh division). The first Mac commercial wasn't even run until Jan. 20, 1984. So you must mean Nov. 84 and then got your Mac in '85. The 800K Apple II drive was released in September '85 in the form of the UniDisk "smartdisk" drive. I have personally obtained one of these drives and attempted to use it with the Mac 128K (bypassing the drive's circuit board). The 128K will NOT format an 800K MFS disk, because the 64K ROM does not have the drivers for a double sided disk and has no idea how to format it. Once formatted, the 128K can read and write and even erase it again. But never originally format it. You must have obtained 800K MFS disks formatted on a 512K which could use the HD20 INIT that told the 64K ROM how to write such a disk. Otherwise, the reason I am asking is that I would love to know if there was a method to get the 128K to format 800K MFS disks on the little sucker, since lost to us (perhaps a third party disk formatting utility?).
Later 1.4 MB and possibly other model 800K drives needed the 128K Mac Plus ROMs to work properly.
Again, I have taken a later 1.44MB Superdrive and attached it to the stock 128K. It functions identically as the compatible 800K drives. Since there is nothing in the 128K ROM that was even aware of SuperDrive SWIM technology two years in the future, I would be surprised if there were any differences which would affect the way a 1.44MB drive works as compared to the 800K which otherwise works perfectly.
