Re: Reading apple disks on PC

[pausch@saaf.se (Paul Schlyter)]

In article <20030723040500.21622.00000401@mb-m07.aol.com>,
Michael J. Mahon <mjmahon@aol.com> wrote:
> Paul Schlyter wrote:
> 
>>In article <FTaRa.1576$KZ.854103@news1.news.adelphia.net>,
>>Steven N. Hirsch <shirsch@adelphia.net> wrote:
>> 
>>> sean wrote:
>>> 
>>>> Paul Schlyter wrote:
>>>> 
>>>>> PC floppy drives have
>>>>> never been able to read GCR disks and will never be.
>>>> 
>>>> 
>>>> Unless of course you are lucky enough to get your hands on an old 
>>>> Central Point Copy II option board.
>>> 
>>> Hmm.  I have one of these.  However, I'm not aware that the support 
>>> software lets you read files from, e.g. a IIgs 3.5" disk.  Wasn't it 
>>> just intended for full-disk copying?
>> 
>>I think he meant the capability of the hardware and not necessarily
>>the accompanying software.  You can always write your own software,
>>but it's much harder to build your own hardware.... :-)
> 
> Considering that it would be necessary to write RWTS
 
Only if the hardware is as stupid as the standard Apple II disk
"controller" (which was only a rudimentary disk controller really;
the Apple II RWTS was the actual "disk controller").  With any real
disk controller chip, you just set some parameters in the disk
controller, then give it a memory address and tell it to read one or
several consecutive sectors into a buffer starting at that address.
 
> and a pretty complete file system (or two) in x86 code,
 
Anyone wanting to attempt that are free to borrow as much C code
as they want from my FID.C (available at http://home.tiscali.se/pausch/apple2/)
to access an Apple DOS file system.
 
> I think this may be yet another case where the hardware is the
> easyware and the software is the hardware.  ;-)
 
Only if the software really would require a complex RWTS equivalent
and the hardware contained only standard components which you could
buy fairly easily.  But when I said "build your own hardware" I was
more thinking of constructing and mask programming your own LSI
chips....... it's not impossible, but it's definitely not for the
faint hearted to do such a thing.
 
But before speculating more, we need to know more about the hardware:
does it contain a real disk controller in hardware, which is at least
reasonably "intelligent"?  Or does it contain only a rudimentary disk
controller in hardware, like the Apple II did?
 
-- 
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