These darned old computers

From: Fred Cisin <>
Date: Mon Aug 26 13:52:00 2002

On Mon, 26 Aug 2002, Lawrence Walker wrote:
> In referring to the "360k" do you mean the model (RS 25-1060) that shipped
> IIRC for the 1000HX ( ?) ? I just checked my COCO M.502 drive and the edge
> connector is slightly different. It would be nice to have a useable 2nd drive
> for my CoCos.

I don't know what butchery they might have done to later models (probably
just putting the power through the ribbon cable).

On the original Coco, the drive was interchangeable with the drives for
the Model 1 (*), and consisted of a "standard" drive mechanism in a case
with power supply, and a card edge extender to bring the 34 pin card edge
of the drive to the outside for cable hookup.

Radio Shack did the drive select through missing pins in the cable. Each
drive had ALL of the drive selects turned on! If you use a more
"normal" cable, then open the case and deselect the drive selects that are
not wanted.

Hmmmm. seems that for drive select 3 (fourth drive), they used a pin that
was originally intended for something other than drive select. 34? (side)
6? 8?
THAT could complicate things slightly if you need 4 drives, or use the RS

(*) NOTE: one exception to the interchange of drives between Coco and
Model 1 was that the earliest drives for the model 1 were Shugart Sa400
drives that only went to 35 tracks, and thus would FAIL on the top 5 or so

Grumpy Ol' Fred
Received on Mon Aug 26 2002 - 13:52:00 BST

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