Good way to archive system disks

From: Fred Cisin <>
Date: Mon Dec 24 12:09:16 2001

On Mon, 24 Dec 2001, Dave Mabry wrote:
> I think I've still got a problem doing this, though. The 5 1/4 inch
> diskettes that I want to image are 96 tpi and standard PC diskette
> drives are 48 tpi. Although the 1.2M AT-style ones were 96 tpi. Not
> sure if I can make one of them work. That might be worth a try.

It is POSSIBLE to read 720K 5.25" using a 1.2M drive. But there can be
complications, particularly with overly "smart" inflexible Wintel style
But a 720K 5.25" drive will work nicely on most machines; the computer
will think that it is a 720K 3.5".

> Another obstacle is that 440BX chipsets only control one floppy drive.
> I don't have an older PC that can control two floppy drives. Am I
> missing something here?

You would be missing the joys of using a classic computer.
Get something a little older, such as a 5150 for the 720Ks, and life is so
much nicer.

> The 8 inch diskettes are Intel's somewhat unique M2FM, not the more
> standard MFM. So I doubt that there is any diskette controller for the
> PC that would read them.

But, ... in theory, ... perhaps, ...
The Catweasel is theoretically capable, but there isn't appropriate
software available. or
The Central Point Option Board was theoretically capable, but there isn't
appropriate software available, AND programming info is trade
secret, therefore reverse-engineered or stolen.

> What I was hoping for was a program that would run under CP/M on the
> target machine that would allow me to make an image file of a diskette
> on that machine. Then I could transfer that image file over to a PC and
> put it on a CD. Thinking about it, though, I might end up with a catch
> 22. In order to make a diskette from one of those images would require
> a running CP/M machine.

An image file would be easy to do, as a dump of the contents of all
sectors. But that might not include the system tracks, and the recreation
of PHYSICAL format would be a little tougher.

> Are you saying below that a 96 tpi 5 1/4 inch diskette drive can plug
> into a PC and be detected as a 720K 3.5 inch drive?

So long as it's clear that we are talking about a 5.25" 720K drive, such
as Tandon TM100-4, Teac 55F, Shugart/Matsushita 465, etc. Using a 1.2M is
still possible, but might have a few more complications.

Grumpy Ol' Fred
Received on Mon Dec 24 2001 - 12:09:16 GMT

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