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TM990/101 M


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  TM990/101 M by Bill Degnan - 06/06/2006 22:06
I have a TI chassis I have been unable to locate documentation. Can anyone help shed some light on the following. .?

The card chassis:
Within a Steel 4-slot Texas Instruments card chassis the size of a shoe box are four Texas Instruments cards manufactured in the US. These cards resemble a regular s-100
card but the 100 contacts are off center, to the left when viewing the component side with the 100 pin side down. Printed on the chassis is Assy No. is 0994676-0001 and Diag
No. 0394677. I do not have a power supply, but I assume you'd attach to terminals on the back of the chassis somehow (?).

Inside are 4 cards.
Two cards are similar are RAM/EPROM cards with 32K in each (8 x 4 rows I assume = 32K?). The RAM is a mix of TMS 4045-30NL, TMS 4045-30, and TMS 4014NL. There are no Eproms
installed, but there are two rows of empty slots on the card. Each card has 8 dip switches.

The third card is labeled TM990/101 M. This appears to be a processor/modem/term card with a TMS 9900JL EP7840 ceramic/gold processor, and a TMS 9901NL chip, etc. The card
has two 25 pin female connectors apparently for serial i/o. An earlier model's users guide:

The fourth card is labeled "universal prototype board TM990/512". This card may be newer than the rest and has an Intel P8253 chip (date = '80). There is extensive wiring on the
back of the card, it could be for a disk drive, I don't know. The card has 2 40 pin flat connectors.

I am hoping someone can point me in the direction for a TM990/101 M Users Guide or documentation about the chassis and/or individual components. I can post pictures by

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  TM990/101 M by Ed Arnos - 08/28/2006 19:03
I worked with these cards during the 1980's. The 101 card needs a eprom chipset in order to run. I recommend trying to find a chipset that runs the Eyring Research PDOS operating system. To make the computer useful you would want a SCSI interface card and a SCSI disk connected to it. The PDOS operating system was distributed on 8" floppy disks. To run, you need +5 , +12, and -12 It expects to see a ASCII dumb terminal connected on Port A.

You have ram on the 101 card and on the ram/rom card sufficient to do something.

There is a subsequent TM990/102 card with 128K of dram that is more useful if you want to create a timesharing system.

The TM990 set included a magnetic bubble memory card which would be a collector's coup if you found one and made it work.

Let me know what you would like to do with this card and I will try to help. I manufactured a backplane and 202 modem for this card set. I also wrote a lot of code for it.

The 9900 has an interesting architecture with a CRU high speed serial communications port and uses memory for its registers so an interrupt context switch can occur in one instruction.

Ed Arnos

  TM990/101 M by Richard Lynch - 12/24/2007 00:14
I have a set of these TM990 cards, including several 101M, 102, 310, and one 203. I also have a TI 13-card backplane supplying the +5, +12 and -12V. I also have the User's Guide for the 101M. Last night I tried to boot each of the 101M and 102 cards, but only one of the 101Ms did anything meaningful. It displayed "ASDBUG June 1985" after resetting, but nothing more and it wouldn't respond to any keyboard commands. None of the other cards got even this far. The 102 cards don't have a reset switch like the 101M, so how do I reset them after power on? Ed, any help you can provide would be appreciated.

Richard Lynch

  TM990/101 M by Bill Degnan - 12/24/2007 00:23
Beats me!

  FAO Richard Lynch (was TM990/101 M) by Stuart Conner - 01/19/2008 17:16
Hi Richard,

Can you reply by private e-mail: ti99 **z** stuartconner(dot)me(dot)uk (replace the **z** with @)? I may be able to help with the TIBUG and LBLA software that will give you very basic functionality. Also be interested in discussing exactly which bits and what documentation you've got.

Best regards,




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