TI-990 console

Texas Instruments TI-990 Page

Welcome to Dave Pitts' TI-990 web page.

The above picture is my Texas Instruments TI-990/4 system. I have a TI-990/10 system with 256K of memory, DS10 disk and 911 VDT. A TI-990/12 system with 1MB of memory, SCSI disk and 9-track tape, and a CI403 serial multiplexor for terminals. I also have TI-990/5 and TI-990/10A CPU boards that I can swap between the systems.

I worked on the TI-990 from its inception, wire wrapped boards in a TI-960 chassis, until 1980. The first 990 was the 990/9 in 1973 and was built for a large Motel chain reservation system. I worked on the cross development environment for the Motel that ran on their PDP-10 and was written in ALGOL. The 990/9 was superceeded by the 990/10 and became commercialized with memory mapping and high speed disks on the TILINE (kind of like DEC's UNIBUS). The 990/4 came out with the advent of the TMS-9900 chip in 1975. The 990/4 was superceeded by the 990/5 (added the TILINE, more memory and three on board serial ports). The 990/12 was added to the product line, in 1979, and added hardware floating point, writeable control store and many other "goodies". I wrote and collaborated on parts of the Operating Systems (TX990 and DX10) and various utility programs, editors, compilers, assemblers and linkers.

Commercial and Military users: If you find this software useful (or necessary) please feel free to drop some coins my way to support the effort. Also, If you no longer have the in-house expertise for the support of these products please contact me for a quote.

Should you have any TI-990 software and documentation, please drop me a note as I would like to preserve it and make it available for others. I'm looking for DX10 RPG and a DX10 Fortran installation.

If you have ANY documentation for the 990/12 Writeable Control Store Assembler and Language or the EI990 Ethernet Programming Manual, I'd love to get a copy.

In seeing some of the retrocomputing effort on behalf of the TI-990 I've got some links that may be of interest:

You will want some software to run with the sim990 program:

If you need Documentation for the TI-990 here is a link:

I've also been working on a GCC port to the TI-990 and TMS-9900. There are also runtime libraries (libc.a, libm.a, etc.) that can be built with the compiler. The instructions to download and install it are here: TI-990 GCC installation.

This home page is maintained by David Pitts. Please email with comments and corrections.
Last modified 2017/02/08.