Re: About 400k Pascal Disk: help !

[mjmahon@aol.com (Michael J. Mahon)]

Jerome Vernet wrote:

>Le 4/04/03 23:26, dans qa6cnTeAeOQdZRCjXTWcpQ@comcast.com, ��Bill Garber��
><willy46pa@comcast.net> a judicieusement �crit�:
>> 
>> Michael J. Mahon <mjmahon@aol.com> wrote in message
>> 20030404154356.28474.00000532@mb-fv.aol.com">news:20030404154356.28474.00000532@mb-fv.aol.com...
>>> This is a single-sided 3.5" format.
>>> 
>>> The question is whether it is MFM or GCR, but the custom controller
>>> argues strongly for MFM.  So there is a very good chance that it can
>>> be read on a PC that can read DD 3.5" disks, by simply reading the
>>> blocks that are on only one side.
>>> 
>>> The Pascal file system is, of course, another issue, which others
>>> have solutions for.
>> 
>> If I recall, HP had it's own system of CP/M in the beginning, but
>> I can't be quoted having never used them. Shop folk were not
>> permitted to operate the inspection room computers, and there
>> were none elsewhere except the office, but I do recall seeing
>> those disks in the inspection room next to the machine's console.
>> As a matter of fact, that was the very machine they used.
>
>We think that the drive is exactly the same as these HP. It's in fact 3.5
>360 k single Sided MFM disc. What should be useful is a prog that can deal
>with Pascal SS disc on a PC, or may be ADFS with a Superdrive Mac. ;-)

Yes, Sony manufactured the first 3.5" drives, and they were single-sided.

The software approach you suggest is quire workable, given only
a mapping of the Pascal file structures on disk to the blocks on
one side.  (The fact that it is only formatted on one side will not
matter if only the formatted side is read.)

Good luck!
-michael

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