spencer@eris.BERKELEY.EDU (Randy Spencer) (04/24/87)
I was talking to Randy Burns this morning, and he was telling me about a
product that someone on this net had mentioned that let one take files
from the Mac to the Amiga and back on disk. Now I thought this would be
impossible. The Amiga has a constant speed drive. There would be no way
to read a disk like that on a variable speed mac drive, so I spoke to one
of our Mac Programmers here (I don't usually speak about work on this net)
and he said that you can do anything you want (if you have the programming
know how. So I asked him if he thought it was possible to read disks back
and forth (kind of like dos2dos, or disk2disk) and he said that the Amiga
uses some funny way to get 880K (plus some) on to a floppy and that he didn't
think that that could be duplicated in software.
So the question still stands: Is there a program (for the Mac or the Amiga)
that lets me read and write disks back and forth so that I don't have to
have a modem to transfer files from one machine to the other?
Should I be posting this question to the comp.sys.mac board? And if I did
who would watch for replies for me?
Thanks again for your support!
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Randy Spencer P.O. Box 4542 Berkeley CA 94704 (415)284-4740
I N F I N I T Y BBS: (415)283-5469
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s o f t w a r e spencer@mica.berkeley.edu
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-daveh@cbmvax.cbm.UUCP (Dave Haynie) (04/27/87)
in article <3302@jade.BERKELEY.EDU>, spencer@eris.BERKELEY.EDU (Randy Spencer) says: > So the question still stands: Is there a program (for the Mac or the Amiga) > that lets me read and write disks back and forth so that I don't have to > have a modem to transfer files from one machine to the other? > Randy Spencer There was a thread (here, or was it elsewhere) awhile back on the Amiga reading of Mac disks. It looks like at least some portions of a Mac disk could be read, but perhaps not all of them. The reason that anything could be read from a Mac disk is due to the Amiga's decoding of the disk format under software control (this is usually done by the blitter, but in this case you might have to throw the CPU at it). The reason you might not be able to read, and probably can't write, Mac disks is of course the speed change that you mention (Mac's trick to fit 800K per DS disk). The Amiga's trick for 880K+ per disk is based in the fact that it must, by the nature of the floppy controller that's part of the Paula chip, write or read an entire track at a time. There are no individually accessed physical sectors on an Amiga floppy, although logically you get 512 byte blocks out of a track (11 per track per side on a standard Amiga floppy disk). Traditional disk controllers must write a sector at a time, and as a result of this they've got to leave a bit of room between sectors so that a little bit of imprecision on the part of the drive head won't clobber neighboring sectors. Any machine, like a Mac, IBM, or Atari ST that writes individual sectors would have trouble reading or writing an Amiga disk. Also, most of these machines have disk controllers that implement the disk format in hardware, so even if they could accurately read the Amiga floppys with their mechanicals, their silicon may not have a clue as to what to do with the format. Amiga's can read the standard 720K format used by IBMs and Ataris with no trouble -- currently there are programs that do this, there will probably be device drivers in the near future. -- Dave Haynie Commodore-Amiga Usenet: {ihnp4|caip|rutgers}!cbmvax!daveh "The A2000 Guy" BIX : hazy "These are the days of miracle and wonder" -P. Simon