Seeking... TI TMS9902 ICs

Randy Dawson rdawson16 at
Sat Jan 17 22:22:03 CST 2015

I loved the 9900! it was screaming fast compared to x86 in 1980 or so.

I bought one of their SBCs, the TI 990 'University Board', it came with a 200+ page course and tutorials on the processor.   Later found their video chip 9918 and adapter board from Eyring Research.

Other than the 99/4 these parts had little use.  TI did make another stab at video chip coprocessors that ended up in the Truevision (AT&T) AT-VISTA framegrabber boards.

Some trivia:  The TI processors had lots of use in TI's industrial PLCs, the PM520 and PM550.  I was in a design meeting with these guys, when management said 'What can we do with the PLC line to compete with Allen Bradley?'  One of the more vocal TI engineers stood up, and said, 'Don't force us to use TI processors.'  Their next gen PLC, the 560, was a standard bus, VME and 68000 based.

I think it still ships today under the Siemens brand, TI sold off the PLC group and got out of programmable logic controllers altogether.

> Date: Sat, 17 Jan 2015 22:53:00 -0500
> From: jbdigriz at
> To: cctalk at
> Subject: Re: Seeking... TI TMS9902 ICs
> On Sat, 03 Jan 2015 10:31:24 -0800
> Al  Kossow <aek at> wrote:
> > On 1/3/15 9:25 AM, Sean Caron wrote:
> > > I've never seen a TI
> > > 990 system in the wild, and only a few folks are displaying 990
> > > architecture SBCs or actual TI-990 systems so the obscurity factor
> > > is there a little bit.
> > 
> > I have at least 6 990s (/4 /10 /12) and several truckloads of
> > boards/documentation/software that no one here has expressed any
> > interest in after talking about them a couple of times over the
> > years. Dave Pitts has several and has written an emulator that runs
> > most of the OSes for them
> > 
> Too bad they are 3000 miles away from me; shipping would be a
> killer :^(. Can't count the times I had 990 stuff lined up to get, and,
> well, stuff happened. C'est la vie, etc. Still have my /10 and BS1500,
> though, incredibly, and most of my 4A and Geneve stuff, although not
> all in the best condition, now. Hanging on to it all through a lot of
> trials, trauma, and general BS turned me into a bit of an antisocial
> jerk for a while, but I'm still glad that I did. 
> For  Caron: I followed this thread with interest, because
> lately I've been considering some 9900/9995/99000-based projects,
> and/or add-on cards for 990's and even 4a's, or maybe a homebrew, so
> the chipsets on Ebay look promising. Look like some kind of 9900 and
> 9995-based MSX2+ SBC's, like a souped-up Tomy Tutor or something. Those
> Altera chips would be the key to system, but I don't see any mention of
> documentation, schematics, etc. Presumably these are hot hobbyist items
> in Japan or the MSX community, and are well-documented somewhere, but
> I'm not familiar with them. 
> The 9902 is not present in the 99/4A console. You need an RS/232
> peripheral or card for that. Readily available from any of sources,
> though, like Al says. 

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