From: wdc50@cd.amdahl.com (Winthrop D Chan)
Newsgroups: comp.sys.ibm.pc.soundcard,alt.sb.programmer
Subject: Re: PC: Reading Amiga disks - HELP!
Date: 30 Sep 92 20:48:39 GMT
Distribution: comp
Organization: Amdahl Corporation, Sunnyvale CA

In article <1992Sep30.172827.7814@cybernet.cse.fau.edu>,
spc@pineal.sci.fau.edu (Sean 'Captain Napalm' Conner) writes:
>In article <1992Sep29.052642.13360@organpipe.uug.arizona.edu>
>hertlinw@helium.gas.uug.arizona.edu (William E Hertling ) writes:
>>In article <1992Sep28.211737.6176@cybernet.cse.fau.edu>
>wolfsond@cse.fau.edu (Daniel Wolfson) writes:
>>>
>>>No can do!  Stop your seaching, it is impossible to read an amiga
>formatted
>>>disk on a PC..  Of course an Amiga can read an msdos formatted disk
>(720k only)
>>>
>>>Sorry for the bad news...
>>>
>>>Dan
>>
>>Sorry Dan, but it IS possible to read Amiga format disks on the PC.
>Some
>>time ago someone wrote a shareware program to run Amiga text-only
>graphics
>>on the PC. It was able to read Amiga disks. I've never done it myself,
>but
>>on the other hand, I stuck DOS type disk drives in my Amiga, and they
>>worked fine, so the drives themselves are compatible (unlike MAC-PC, 
>>which requires additional hardware on the part of the PC).
>Unfortunatelyu
>>I no longer have this software, nor do I remember the name of it.
>>
>  Sorry Bill, but it is NOT possible to read Amiga format disks on the
>PC. 
>While it is possible to read MS-DOS disks on the Amiga, it is only
>because
>it is relativily easy to re-program the disk controller on the Amiga to
>do
>so.  It is not so on the PC, because the controlling hardware
>different.
>
>  On the Amiga, the hardware controller can read in an entire track in
>one
>revolution, so it can do away with most of the sync-ing and sector
>information that needs to exist on the disk for a PC diskdrive to work.
>Why
>do you think that the Amiga disks can hold 880K+ worth of data while a
>regular PC disk can only hold 720K? (for a total difference of 160K in
>favor
>of the Amiga).

I don't know all the exact specifics of how the Amiga handles it's drives, but
NOTHING is impossible. A few examples being MacInDOS which lets you read and
write MAC format diskettes which use Fixed linear velocity (the media below the
head moves at a the same velocity no matter where the head is, so the platter
adjusts it's speed depending on head position). PC's use Fixed Angular velocity
which means the angular velocity is the same thruout and thus the platter speed
is constant.

Another is several format programs such as VGACOPY which patches bios to
let you
format 3.5" disks upto 1720k!

When someone is determined, there's always a way to monkey a solution
out. Might
not be fast, but hey, it works. :-)

cheers
-- 
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  Winthrop Desmond Chan             | Email: wdc50@duts.ccc.amdahl.com
                                    |        xpax@leland.stanford.edu
  Software Engineer & Trouble maker | M*d:   Pax @ LambdaMOO / xpax @ TerpMUD
  Processor Validation Projects     | ** Tax-paying grunt by day...    **
  Amdahl Corporation, Sunnyvale, CA | ** Brainless student by night... **

  Disclaimer: All comments are my own and do not reflect that of Amdahl Corp.
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