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OT: TI990/10A

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Apologies for being off topic, but this forum is where I know I can reach Fabrice.

 

For some time I have been trying to find out which chip powered the TI990/10A mini. It certainly is a chip from the TMS99XXX series, but whether it is the 99110 or a version that was only used in TI minis (and if so probably numbered TMS99000) remains a mystery to me.

 

Via a google image search I came across a forum thread from 5 years ago in which Fabrice participated:

http://forum.system-cfg.com/viewtopic.php?f=10&t=2385

It has an image of a 990/10A system board (http://img11.hostingpics.net/pics/890850tm990_10a.jpg), but the image of the CPU chip is blurred: perhaps the markings have faded, perhaps it is just glare in the photo.

 

Fabrice, are you familiar with the owner of that 990/10A system board and can he be reached to inspect the markings on the CPU chip?

 

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As far as I know, the TI990/10 used the 990/10 CPU board (a TTL implementation of the processor on a PCB). The 99000 was a later development that incorporated the whole PCB in a single chip. The TMS9900 is a simplified version without privileged mode and other features.

 

So you don't see the CPU because the whole board is the CPU.

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Yes, the 990/10 was a TTL implementation. I think it was spread over 3 boards. It dates from 1975.

 

The 990/10A was a cost reduced version dating from 1982. See here for details:

http://www.textfiles.com/bitsavers/pdf/ti/990/990-10/2302633_990-10A_GenDescr_Sep82.pdf

That manual actually has a picture of the board in it too (page 1-2), but again the chip markings are impossible to make out completely (but it seems to start with "99").

 

I think the 990/10 and the 9900 (used in the 990/4 and 990/5 minis) have a common ancestor in the prototype 990/9 dating back to 1973-74.

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Somewhere in my random collection of odd TI boards, I have a small circuit card with a TMS99000 chip on it. It was given to me by someone who knew I liked odd TI things, but he had no clue what the board did. I'll have to dig it out again and see if I can identify it now. . .but that may be a while.

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Thanks all!

 

In the 990/10A documentation I was not sure wether "TMS99000" should be taken literally, or as meaning TMS99xxx (as it does on for instance on the cover of the 105/110 data book). Now that Ksarul has confirmed that a chip marked "TMS99000" really does exist I think it should be read litterally. I still hope to find confirmation on an actual 990/10A board though.

 

Perhaps some day documentation for this chip will creep out of the woodwork.

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Oh man, I'm getting a real itch to continue working on the 990/10 skeleton in MESS ... it is already there, but needs a lot of work and update to the current state of the framework. I know it's somewhere down the todo pile on my desk.

 

But as you can see recently, I'm trying to get some things done by now... :)

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Thanks all!

 

In the 990/10A documentation I was not sure wether "TMS99000" should be taken literally, or as meaning TMS99xxx (as it does on for instance on the cover of the 105/110 data book). Now that Ksarul has confirmed that a chip marked "TMS99000" really does exist I think it should be read litterally. I still hope to find confirmation on an actual 990/10A board though.

 

Perhaps some day documentation for this chip will creep out of the woodwork.

 

 

Hi maybe this here is creeping out of the woods, don´t know :)

 

 

post-41141-0-92490900-1440544499_thumb.jpg

TMS99105A_and_TMS99110A_16-Bit_Microprocessors_Data_Manual_Nov82.pdf

 

 

 

or this (comes from my FTP as to big for AA)

 

 

post-41141-0-43567700-1440544625_thumb.jpg

ftp://u67140205-atariage:[email protected]/_DOCUMENTS.bak/TMS-DOCs/TMS99000er/TMS99105A-TMMS99110A-DataManual.pdf

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...if you need software or more stuff for the 99000er and/or TI-990, just let me know

I only have to sort this first, as this is "off-topic" for me and laying around :)

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I found this thread:

http://www.cpu-world.com/forum/viewtopic.php?p=150371

 

Apparently, a TMP99000 chip existed. Now take a good look at the last chip pictured in the above thread and then look again at that French TI990/10A cpu board:

http://img11.hostingpics.net/pics/890850tm990_10a.jpg

(the cpu is the ceramic chip on the left).

 

See how the markings are very similar, with the triangle and the little square next to pin 1? I think I can even make out the letters "TMP" in the top line of the marking. Until I find other material saying something different, I'll go with the belief that TMP99000B chips powered the TI990/10A mini's.

 

The question that remains is in which ways the TMP99000B was different from the TMS99105 and TMS99110.

 

Another intriguing thing is why TI stuck with the "TMP" coding (i.e. engineering sample). The date code on the chips pictured in the CPU-World thread are for late '83, whereas the TMS99105 and TMS99110 chips were released in late '82, as was the 990/10A mini. Karl Guttag once mentioned that the 99000 worked "on first silicon"; perhaps the reason was that it just worked and TI never saw a reason to change the coding.

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Maybe they were test samples to see what they needed to put into a 99120? It looks like these 99000 chips went through three different revisions (A, B, C). This is beginning to pique my curiosity enough that I think I may have to see if I still have the weird little board with the 99000 chip on it buried in one of my hardware boxes. . .

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Posted (edited)

Record late reply for this topic.

I now happen to have a TI990/10A cpu board and can confirm it has a TMP99000A cpu.

 

Jim

 

101462881_2021-04-1514_46_12.thumb.jpg.7e0900c9c124f897b9f842b0184d7e1d.jpg

 

 

 

481507355_2021-04-1514_46_21.thumb.jpg.9a5bc6ad87e545be8146cd52b5495ef0.jpg

Edited by Jimhearne
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The poor little processor is rather dwarfed by the other chips on the board.  ;-(

 

I happened to notice a TMP9900 processor in this little lot: [https://www.ebay.co.uk/itm/402789789320]. It doesn't really have the look of a Chinese remarked chip, but then a date code of 1987 doesn't make much sense either.

 

 

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yep, and TMP9900 also sounds strange for the TI-99, doesn´t it ?

 

grafik.thumb.png.236f132a230376a14f41db680fe4f292.png

 

 

TMP9900.thumb.jpg.816ca81807e731b5f9546cb932eb8730.jpg

 

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