kpmancus@phoenix.Princeton.EDU (Keith P. Mancus) (05/16/88)
I am distressed to hear that the amiga drive can only read the out 32 tracks of a Mac disk. Can anyone confirm this or suggest a fix? It sure would be nice to be able to read in text and fonts by directly inserting a Mac disk w/out messing with the serial port, independently of whether the Sac ever works. -KPM <kpmancus@phoenix.princeton.edu> Keith Mancus
doug-merritt@cup.portal.com (05/17/88)
Keith Mancus writes: > I am distressed to hear that the amiga drive can only read the >out 32 tracks of a Mac disk. Can anyone confirm this or suggest a fix? Sure, it's fairly common knowledge. The problem is that the Amiga disk spins at a fixed speed, whereas Apple has theirs vary depending on where it's reading/writing. That's why Mac drives make "musical" sounds. The fix is to buy a Mac diskette drive and start figuring out how to interface it to your Amiga. Have fun. Asking for confirmation on this bit of news strikes me as a bit strange, inasmuch as you are replying to a posting by the guy who did Magic Sac in the first place. One would think he'd be a fairly reliable source of information on such a thing, no? Doug Merritt
dsmall@well.UUCP (David Small) (05/18/88)
(The discussion was, can the Amy read Mac disks). The Mac disks are recorded at five different speed ranges, for tracks 00-0f,10-1f,20-2f,30-3f,40-4f. The innermost tracks' data rate is the 4 microseconds per bit you expect under GCR; hence, a byte comes off every 32 microsec (much like MFM, although of course that's covering up MFM encoding & GCR denibbleizing). The Amiga is looking for data at 4 usec/bit also. Towards the outer tracks (00), the data is at 3 microsec/bit. The Amiga doesn't like to seperate and clock this in; I can't say I blame it much. But anyway, my experience has been, the outer 32 tracks only can be read. -- Thanks, Dave