[Coco] FDD 26pin to 34pin

Robert Emery theother_bob at yahoo.com
Tue Aug 8 10:18:56 EDT 2006

If the 26 pin drive is going to be D0 or D1, you don't have to worry about connecting DS2 to it. I'll try to remember to open up my CC3P and get the exact pinout I used, maybe a picture or two. If you *must* have it as D2, you *could* jumper the drive as D1 and connect the DS2 line where DS1 would normally go (on that drives connector only.)
One thing I would recommend for the 3.5" drive (works for DS 5.25s also) is a manual side select switch. Cut the line before it goes into the drive, feed it to an inverter. Use an SPDT switch with the Non-Inverted signal on one throw, the Inverted signal on the other, and the common pole going out to the drive.
I also used a DPDT switch to allow me to swap DS0 and DS1 so I can use either drive with software that is hard-coded to only run from drive 0, which is a large portion of CoCo software (especially OS9 stuff).
Good luck,

----- Original Message ----
From: Chester A Patterson <vchester at setec-cr.com>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Sent: Tuesday, August 8, 2006 8:51:57 AM
Subject: RE: [Coco] FDD 26pin to 34pin

OK. I figured as much. Most signals are no problem, DS0, DS1 and DS3
(HS) have where to go... (please be patient, I'm learning and
remembering, fast) I see now why we can only have up to 4 SS FDDs or 3
DS FDDs. However, where to send the Coco DS2 signal on the 26pin FDD?
And I guess the READY signal remains N/C?

>>>>> <<<<<
The floppy drives use a bus topology. All signals go to all drives.


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