IBM drives in a Kaypro

From: Fred Cisin <>
Date: Wed Feb 12 19:28:01 2003

On Wed, 12 Feb 2003, Tony Duell wrote:
> According to the O&A TechRef, there are 2 distinct 40 cylinder drives :
> The 'Slimline' drive used in the PortablePC and PCjr. This des not have
> the asterisk

Originally a Qume "Qumetrak 142"?
They existed BEFORE the 1.2M was released, and therefore before the

Which brings up that when I listed the various parameters that might
matter, I failed to include step rate. The Qume drive was arguably the
first "half height" 5.25" drive, and it was SO slow that changes needed to
be made in the OS to keep from timing out waiting for it to seek.
Some say that it was the worst drive ever sold; I don't agree - I had some
BASF 2/3 height drives that were worse.

> The double density (360K) drive for the PC/AT. This does have the asterisk.
> They are difference electrically (made by difference companies?). I think
> the use of pin 34 on the connector differs too.

At about the time that the 1.2M was released, there was a change in the
use of pin 34. One use was "READY"? the other was "DISK CHANGED"?

> Officially you shouldn't interchange them.
But that never stops us.
Received on Wed Feb 12 2003 - 19:28:01 GMT

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