Interesting Heathkit Expansion Board

From: Patrick Rigney <patrick_at_evocative.com>
Date: Fri Aug 22 12:36:00 2003

I just pulled a really interesting-looking expansion board from a dead
Heathkit H-89 I acquired a few months ago, and I was wondering if anyone
knew anything about it, and/or had documentation and software to support it.
And I know is what I can see; can't find anything on 'net.

It's an N.O.G.D.S. (New Orleans General Data Services) HA-89-3-B. This
thing is a whopper, the only thing it doesn't seem to have on it is another
CPU. It has:

* AY-3-8910 sound chip;
* SC-01-A voice processor chip;
* ADC0809 (there are four ports marked JOY1-4 on the board, so I'm assuming
joystick pots);
* 8253 Timer chip (some of its outputs extended to a 10-pin header);
* 8259 Programmable Interrupt Controller;
* TMS9918 video display processor and supporting RAM (there's cable running
off the board that terminates in a RCA jack), for a second video display
apparently;
* AM9511 math coprocessor;
* a couple of PALs and the usual array of buffers and decoders.

So for all things, this looks like it was meant to support some really
interesting applications on the H-89, maybe drawing/CAD, etc. (but the sound
and voice chips?). The machine it came in also had a battery-backed
real-time clock expansion board (with AA battery that leaked down onto the
flyback transformer, yuck), and a parallel port board.

I'd love to play with this thing, but I thought I'd ask before I spent
hours following traces...

--Patrick
Received on Fri Aug 22 2003 - 12:36:00 BST