[Coco] Re: Any documentation or info on Tandy's Coco hard disk controller?

[John E. Malmberg]

John Guin wrote:
>  Hello all,
> 
> I managed to snag one of these hard disk controllers at a garage sale, and
> it powers up to "Disk Extended Basic 1.1" on my Coco2.

I was under the impression that there were no ROMs in the unit from 
previous discussions on this forum.

> But that's all I can do with it - I have no documentation for it otherwise.
> Does anyone know anything about it or where to point me for docs?  I looked
> through Marty Goodman's hard disk article from the Rainbow (July 89?), but
> it did not mention the Tandy controller.

As I understand it, the controller was just a bus adapter that adapted 
the COCO bus to match the hard disk espansion interface on the TRS-80 
models III/IV.

The actual hard disk controller is an MFM controller in the hard drive 
0.  An MFM disk controller can typically controll up to four 150 Mb 
drives if you can find them that work. :-)

At the last time I priced used MFM drives from a dealer of that size, it 
was far cheaper to buy a Cloud Nine or Glenside IDE controller and a 
compact Flash unit.

-John
wb8tyw(at)qsl.net
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