[Coco] Tandy Hard Disk Controller

[Ward Griffiths]

On 03/03/2006 01:46 pm, Neil Morrison wrote:
> ----- Original Message -----
> From: "Gene Heskett" <gene.heskett at verizon.net>
>
> > Did they actually ever *sell* one?  I looked at the one the local shack
> > had, but at $129.95 I couldn't bring myself to write the check, NDI
> > what ever became of it.  AIUI at the time, it also required another
> > interface controller card between its cable and the drive proper &
> > nobody had a clue as to what it might be required to do, or if it was
> > even available.  It had a maximum of 3 16 pin dips in it that even if
> > gold plated, couldn't convince me it was worth the asking price.
>
> IIRC, you needed a R/S 'Primary Drive', which contained the HD controller.
> This was the standard R/S setup. The VERY expensive 'Tandy Hard Disk
> Controller' was just a very simple interface with a few chips.
>
> I'd like to get a schematic for it - never found one.

Might not be too hard to figure out.  The cartridge for the Coco was basically 
some firmware (I assume) and a conversion from the Coco expansion bus to the 
Mod 3/4 expansion bus, just as the boards that went into the Mod 2/12/16/6000 
were.  Yes, the primary drive box contained the actual controller.  The cable 
from a Mod 3/4 bus was straight-through.
-- 
Ward Griffiths    wdg3rd at comcast.net

I think boys might benefit from owning a Barbie doll; every young man
should understand what an expensive proposition it is to cohabitate with
a narcissistic woman built like a stripper.  --  Tony Woodlief