Re: Reading 5.25" Pascal 1.3 on a Mac

[phenix@interpath.com (John Moreno)]

Neil Parker <nparker@cie-2.uoregon.edu> wrote:

] In article <199701020738517426609@roxboro-174.interpath.net>
] phenix@interpath.com (John Moreno) writes:
] >Sheldon Simms <sheldon@atlcom.net> wrote:
] >] Well actually, Apple did make a PC-compatible 5.25 drive for the
] >] Mac specifically for the purpose of reading MS-DOS disks, but that
] >] wouldn't help your project since the PC-style 5.25 drive couldn't
] >] read an Apple Pascal disk.
] >
] >How sure are you of this?  That's what I thought at first about the
] >3.5 disk, until I tried - now it's working quite well. What's the
] >difference between a disk for the Apple II and a PC disk?  I've used
] >5.25 disk out of the same box on both.  I'm not SURE that it can be
] >done, and I would appreciate hearing from somebody that would be
] >willing to try.  All they would need to do is email me their address
] >and I would send them a diskette which they could try to read with a
] >disk editor - FEdit, Norton Util. or something similar.
] 
] Physically, there's no difference between Apple 5.25-inch disks and
] any other non-high-density 5.25-inch disk.  The problem is the disk
] controller hardware--disk controllers have to make certain assumptions
] about the way the bits are recorded as magnetic impulses.  The
] assumptions made by Apple and IBM are totally incompatible with each
] other.

So I've heard, it seems that when apple was making the 5.25 drive for
the mac they should have thought of that.

] Apple's SWIM disk-controller chip (used on the Superdrive controller
] card and in all recent Macs) recognizes both the Apple and PC
] bit-encoding schemes, but I have no idea whether or not it's possible
] to hook up a 5.25-inch drive to a SWIM chip.  If it is possible, it
] would certainly require special driver software to be written.

The only thought I've had is that it might be possible to build a single
board computer that does the work of the disk controller, with a serial
connection to EITHER a pc or mac.  After all, the only real problem with
using a  apple II is the size.

--
John Moreno