[Coco] Issues with 26-3022 interface

[Mark Marlette]

Daniel,

This HD mod was created by Robert Brose of our computer club many years ago.

I have done this mod, it works. I also added a line from the controller to the drive to automatically switch the transfer rate clock based upon the sensors in the drive rather than just the descriptor.

With that said...this is NO easy mod. Almost easier making a new controller.

It requires a the MB8877A(??) memory loss ATM upgrade and then there was also a speed issue running at 1.78MHZ as well. A chip that needed replacing. Was pinged this past weekend on this at Cloud-9 and haven't had the chance to look up my work in my project documentation book. I have it.

The file was up on RTSI for a long time. ????

Regards,

Mark
http://www.cloud9tech.com




________________________________
 From: Daniel Campos <daniel.campus at gmail.com>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com> 
Sent: Monday, February 11, 2013 9:00 PM
Subject: [Coco] Issues with 26-3022 interface
 
Hello,

I just acquired from ebay a 26-3022Tandy interface, but I'm having a bad time to make it work with a DSDD drive that I just extracted from my CP500 (TRS-80 model III brazilian clone). For what I know, the drives from CP500 have the same configurations as a TRS-80 original drive. The drive work like a charm on the CP500.
I made a brief movie showing the error and the functioning of the drive (my apologies, but the movie is in portuguese).

http://www.youtube.com/watch?v=oeiCJYa3jic

Any hints on what I need to look at on a TRS-80 drive to work with the Coco ?

Just out of curiosity I tested a 5 1/4 HD (1.2M) Drive from an old PC and I could make a DSKINI (even with an IO ERROR at the end) and also a SAVE and a LOAD on a BASIC program, so it appears that the interface is working as it should.

I also take note on several sites that a mod for HD drives is around for this interface. Anyone knows where to find a documentation of this mod ?

Thanks!
Daniel

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