[Coco] Issues with 26-3022 interface

[Bruce W. Calkins]

----- Original Message ----- 

From: "Daniel Campos"

> 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.

>
> 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



=================================



The 26-3022 disk controller is the first model disk controller and needs 12 
volts to operate properly.  The CoCo 2 and CoCo 3 did away with the 12 volt 
line supply, so this controller has problems with them.  To use double sided 
drives requires fully toothed cable connectors AND either a hardware kit to 
access the other side as a separate drive, or an adjustment in the 
ROM/ROM-in-RAM.



That SAVE and  LOAD is a good sign.



The mod for HD drives is involved and the parts have been off the market for 
decades.  I gave up on collecting the parts almost 15 years ago.  Not that 
it would have been fruitful, I never did put my hands on a 26-3022 
controller.



Bruce W.