This mini forum is intended to provide a simple means of discussion about the Texas Instruments  TI 99 / 4A computer. If you want to share your own experience or memories, or add relevant information about this system: post a message!

I had one of these as a kid. Sadly, I could never get it to work

In September, 1979, I went to work at Texas Instruments in Lubbock, Texas, where the TI-99/4 and 99/4A was mostly manufactured. I was an electronic technician and did soldering and wire-wrap on prototypes in development, mostly software cartridges and add-on devices, as well as worked in testing, repair, burn-in (each new system was left on for several days, I think it was, then re-tested). And I helped train people on the assembly line. I did the wire-wrap prototype version of the speech synthesizer module$ a female engineer designed it$her name escapes me at the moment. .That speech synthesizer was a big deal for its time. She and I were the only two women in that module (and most of the rest of TI) who weren''t assembly line workers

Even though I worked on those computers, I could not afford to buy one for myself! Lordy, they were about $1,700 with all the extras such as the cassette tape drive, if I remember correctly, a fortune back then. But I did have a system at work to use! Much different than programming in FORTRAN on a mainframe!

In those days, another "module" or modular building at TI actually repaired people''s broken calculators and mailed them back to the user. Imagine that.

TI had these automated mail robots that followed a special painted line on the floor, in and out of modules and up and down the big hallway. We used to put stuff in front of them to see what would stop them and what wouldn''t. For 1979, it all was very futuristic to me.

Later, I moved to the Front End module to make more money, where I ran a boron/phosphorus ion implant machine, one of the several hundred processes in creating semiconductor chips. The implant machines were these huge particle accelerators that were the crankiest machines I ever worked with. The chips have multiple layers, and these machines placed a positive or negative charge on the unmasked areas of a chip''s layer. We made the first 256k memory chips there! Then I went back to college after I made enough money, and left TI and Lubbock, which were both good to me.

Ahhh the old tank TI 99/4A. So well built and so underappreciated. It actually plays games well and many of its educational software like Plato and the GROM carts were quite good for their time. If it only weren''t for that infernal PEB. That monstrosity is just a lump on the desk. Shame Custodio Malilong doesn''t make the fabulous microPEB anymore. Such a great device and so small. But if anything, he deserves great recognition for his device and making the TI more useable.

The TI-99/4a was a follow up to the TI-99/4, which is missing from the museum. The machine was at its time the most powerful on the market, at 16-bits and screaming fast, but TI mandated that everything developed for it had to go through the GPL interpreter, which slowed program flow to start with. But the BASIC interpreter was written in GPL, so it was double interpreted, making it the slowest executing BASIC ever released. And TI sought to keep all software release in house, which proved to be a horrible business model, as has been seen more than once over the years.

The TI-99/4a was a follow up to the TI-99/4, which is missing from the museum. The machine was at its time the most powerful on the market, at 16-bits and screaming fast, but TI mandated that everything developed for it had to go through the GPL interpreter, which slowed program flow to start with. But the BASIC interpreter was written in GPL, so it was double interpreted, making it the slowest executing BASIC ever released. And TI sought to keep all software release in house, which proved to be a horrible business model, as has been seen more than once over the years.

There''''s an interesting site about TMS99xx stuff :

http://www.avjd51.dsl.pipex.com/

Has quite a lot of stuff on the TI TMS9900/TMS9995 hardware including a breadboard self-build computer based on the TMS9995

Well worth a look !

Like Jim O., I enjoyed countless hours programming (mainly for the speech synthesizer) and playing what few games my friends and I shared.

What hasn''t been mentioned here is that, due to the motherboard''s unusual design, you could not place these machines on a metallic surface during operation. This would cause components to misbehave and overheat due to induction currents in a few of the coils.

Still, despite its crippled design, it was a fun computer to use.

http://montreal.kijiji.ca/c-acheter-et-vendre-ordinateurs-Texas-Instruments-Computer-99-8-W0QQAdIdZ400504807

This was the first 16 bit home computer and had unparalleled speech capability for the time but TI crippled the rest of the machine rather than take advantage.
For instance could you imagine any computer company today selling a unit with zero main memory, the CPU running only off of the GPU''s vram? That''s pretty much how TI did this thing.

Nevertheless I got countless hours (days, weeks, months?) of enjoyment out of this machine, mostly from programming or program mods, hours of Parsec, and exploring the bounds of the Speech Synthesizer and Terminal Emulator cartridge.

I had one when I was a teen. We had both the 99 and the 994a. Also had the expansion box with 32k of ram. I wrote asteroids in assembler on it. Had to do my own movement processing of the sprites since I needed the ram space the sprite table used. Kind of liked the processor. You could designate any 32 bytes for a 16 register array. Most operations were direct memory to memory. Slow machine but that was due to the gimped architecture which there was no excuse for other than TI didn''t want people using the thing for general computing.

I still have a TI-99/4A in my closet, along with the Peripheral Expansion Box which contains a 32K card, an RS232 interface, a disk controller and floppy drive. I also have an external floppy, a Solid State Speech Synthesizer, and a TI-99/4 Impact Printer which is a modified Epson MX-80. The whole shebang has been sitting in that closet since ''96 when I got an AST PC. Maybe it works, maybe not, but I got endless hours of entertainment from the cartridge and disk software that I bought for it. Somewhere along the way, I remember buying a replacement keyboard from Radio Shack. The new keyboard was the off-white version.
Memories, memories...

This was the first computer my family used. We had a small attached sound verbalizer attachment that went to the side of it which could be purchased. It made a computer voice type sound and was used with educational software for me.

Similar story, got very involved in Ti-Basic, wrote lots of games and utilities. Even a simple word processor. It also changed my life. I am now an applications developer. Anybody in Florida want my old consoles?

Paul
php mysql
Oracle APEX

this is just the keyboard

i found one of these in my closet in perfect condition and i was wondering what it was worth if someone knows please email me at ponzio247@gmail.com

yesh, the ti-99 was the bees knees until the Commodore 64 and sinclair spectrum came out. After that, it went down the tube.

sito veramente bello ottimo :-)
by http://www.computerbit.net

Up until a few years ago I had a prototype for the TI99-4a computer.
I worked with someone in Maryland whose friend was on the R$D team. I wrote some programs and sold them on tape at Software City stores.
He gave the prototype.

I sold loads of these while working for Dixons. Technically superb and very reliable but doomed along all others by default.

Parsec was a great cartridge, though...

One item of note is that the bus architecture for the Peripheral Expansion box (PE) was the basis for the NuBus used in the later Macintosh computers.

I used my TI for years (from '83 until some time in the early 90's) even after getting Apple II's and PC Clones. I still run an emulator to show my kids some of the games and applications I wrote for my self.

I bought one of these 99 4A units from JC Penney's for $400 around Christmas 81 or so. Several months later, the Commodore 64 came out and, frankly, I was tired of poking in programs from the magazines - especially the machine language ones that you could not really troubleshoot. They either worked or they didn't. When the C64 came out, the price on the TI dropped way down, but I decided to try to send it back to Penney's. They took it back and crediitted my fully!!

Processor not connected to RAM !

I bought one of these in about 1983 after watching the price drop from about £700 (including an NTSC colour monitor as a PAL modulator wasn’t available at that time) to £60 (including an external modulator box). At that point more popular computers like the Commodore 64 were well over twice that, although Commodore had made their own mistakes such as the Plus 4 which was available for about the same price as the TI99/4A

The big problem with the stock TI99/4A was that the processor wasn’t connected to the RAM ! Instead all RAM access had to be done through the Video controller. This meant that while TIs own cartridge based games ran smoothly, any third party games, which had to be loaded from tape, ran incredibly slowly. I bought a TI99/4A version of the classic text based Star Trek game and the characters words appeared slower on the screen than they did on the teletypes at College.

An extra RAM board was available from TI but I seem to remember that it had to be fitted in some sort of expansion frame and together they would have cost many times what I had paid for the computer. After just six months I had had enough and sold the TI99/4A for£30 and bought a Toshiba HX10. Interestingly this used the same video chip, but with separate program memory and video memory was vastly superior.

I saw a couple of these displaying interactive science game programs at the museum of scinece and industry in Chicago. They were linked to a button press type interface, it's good to see these have some use after 20 odd years

The TI 99/4A was my first computer as well. I quickly acquired the p-code card, so that I could use Pascal at home too, not only at university.
My interest for this machine turned into the system itself. That resulted in building a real-time clock and an I/O-card, with both digital and analog I/O. I also made an analog joystick for the machine.
The disk controller got replaced with a CorComp, which had four 360 K drives connected to it. I made a secondary expansion box for the two extra drives.
I also made a 64 K memory expansion, installed inside the console. It could be paged in in 8 K pages, to give the machine 64 K contigous RAM, if desired. This memory is on a 16-bit bus, thus allowing a 110% performance increase for the computer, compared to all 8-bit RAM being used.
I modified the p-system to support true multi-tasking, as well as bitmapped graphics, thus making the turtle graphics possible for Pascal in the 99/4A.

Unfortunately, there weren't that many Pascal users at hand, since the cost for that system was pretty high.

About the comments for the 4-bit bus below: The machine was originally intended for a processor with an 8-bit data bus, TMS 9940. But that wasn't available in time, so they had to adapt the 16-bit wide TMS 9900 to an 8-bit data path. Hence this construct was a quick fix to get the computer out, not a design target.

In the 1980's I picked up a ti-99/4a from a manager at work. I grew fascinated by two things, the 16 bit processor in the TI-99 and also how slow it was! I started my own company, LGMA Products, and produced a FORTRAN compiler for the TI-99. My first computer show I was introduced to the MYARC Geneve, and grew fascinated with that device, so I ported the 99 FORTRAN compiler to that. It really had some performance. Later I grew interested in C, and Ron Lepine, who was the ti-99 sysop on BIX (Byte Information Excchange) passed along the source code for an assembler written by a professor in Arizona. Modified it heavily to produce compatible ti-99 loader formats, and then went on to port a 68000 assembler to the TI-99 (it was called "Big-C"). The Small C guy in Canada helped me a lot, and a person in Buffalo, NY called Elmer Clausen helped me so much with the trig functions in FORTRAN.

All in all sold about 1,000 of these FORTRAN compilers, and people would send me programs that were written with it. Asgard computing actually released a few games written in FORTRAN that were advertised as "assembly programs".

I attended various computer faires, it really was useful to my career as it forced me to learn all aspects of a business (which is really why I did it). It certainly was not a profitable venture, I estimate I worked for about 1 cent per hour on the whole project, but the final result was very rewarding and the project helped me manage large projects, and I became a better indvidual and employee of my company as a result. I also made friends world-wide with many individuals, some of whom I stay in contact with to this day.

It was a shame the TI-99 was shut down when it did, the 16 bit assembly code was really a joy to use. There was so much after-market interest in the product and a lot of good friends were made.

BTW.. for those who might be interested, LGMA Products was the name of my company. LGMA stood for "Little Green Men Associates", which was based on a science article by Isaac Asimov regarding pulsars, which were originally thought to be possibly generated by alien intelligence or "LGM" little green men.

My wife and children were very supportive when I did all this work. It was really something looking back thinking I did all that with two 96k floppy disk drives, the Editor/Assembler, a very slow dot matrix printer that I built myself from a HeathKit (remember them)? The manual was prepared with TI-Writer, printed on a slow daisy wheel printer, and I received many compliments on it.

Some subsequent projects for the Geneve included a windowing system based in part on Berry Miller's windows, and a mouse driver from Bruce Hellstrom.

My other passions were an Amiga (what a machine) and in 90's power book Apple. Now I am a lowely PC dell user, it was much more exciting in the old days!

First time I've been here, so here goes. I bought my TI-99/4A in 1980. I used it for a couple of years until I got shipped to Saudi Arabia. Put it in storage and there it has remained until 9/6/05 when I bought out the box with the computer in it and the PEB, all my games, etc. The feeling of ecstacy I had at seeing it again was incredible. All the memories of wriitng my first program in x-basic, the voice emulator. The PEB with a whopping 32K expansion module which brought me up to a grand total of 48K! Well kids, here it comes. I got everything out and set up and hooked up and when I turned on the power, the computer came up with the standard message on the screen of "Press any key to continue". In anticipation I pressed "any" key. Nothing happened. I pressed another key. Nothing happened. Now, the question poses itself to me. Since I am getting the standard message, why is nothing happening? Could it be that 25 years in storage could have caused the BIOS chip to lose its memory and therefore no longer know what to do when a key is pushed? Or, could it be that the keyboard is just no good? But how could that be? A keyboard is just a bunch of Hall Effect switches that have no moving parts. So now I am in a bit of a conundrum. Ask for help from one of you oldies like me.(aaarrrgh the pain of it) or just go look for another system for sale. If any of you have any ideas, please feel free to email me at lynnparks1949@yahoo.com It will be greatly appreciated.

My father wrote many a program for the TI-99/4A, so naturally I grew up using it. In fact, I think I'm still afraid of the wumpus. ^_^ We still have plenty of my father's games and utilities lying around (the ones that were actually copyrighted and marketed, anyway) and I'm dying for the day when I can find one with everything I need to play them again.

Win99/4A version 3.004 - For those of you that have packed their actual TI 99/4A & GENEVE 9640 away, Cory Burr recently wrote Win99/4A version 3.004, an EXCELLENT and superior simulator of the TI 99/4A with full speech capabilities, sound capabilities, and very good module compatibility. You can now get back to writing programs in TI Extended Basic, using the Super Cartridge, using the Mini Memory Cartridge, utilizing the 'Funnel Web' quasi operating system, and using the good educational modules again for your nieces, nephews, and other children; all of this now on the PC. Just go to on the http address below. It will take you directly to where the file is located and can be downloaded: http://www.99er.net/download/details.php?file=87 Over 200 Cartridges (Modules) in file format are available for download for Win994a. Just go to on the http address below. It will take you directly to where the files are located and can be downloaded:
http://www.99er.net/download/files.php?cat=15
Download and uncompress the cartridge(s) item. This may take a little while since the file is roughly 27meg. Uncompress the contents of this file into the "carts" directory under the "Win994a" folder of your hard disk. This will make all 200+ carts available to Win994a next time you start it up. Enjoy. Try it!
The site listed below has PC archives of “almost” every PC99 version [a commercial emulator] of all the good TI99/4A programs known to mankind!
Just download the archives and run them at your leisure. You can then convert the .DSK [the commercial format] to .V9 [the freeware standard format] files with the PC992V9 program available for download at:
ftp://ftp.whtech.com/v9t9/Convert%2...ks%20to%20V9T9/ then rename .V9 [the freeware standard format] files to .TIDisk [the Win994a file format suffix] files from the command prompt in DOS.
ftp://ftp.whtech.com/pc99/archives/

I got my 99/4A in 1981. It changed my life. Learning X-BASIC literally propelled me into the future. I bought every book I could find and used them till they were in shreds. I loved the speech synthesizer and got quite good at incorporating it into little music pieces. I got the assembly language module and things really started heating up. I still remember a quarter century later the first time I got a hex subroutine to work. I remember that little stainless box like it was my first teddy bear, I even remember how it smelled.

Man oh man, this was the first computer I learned how to program in BASIC. I really took it seriously. I must have made well over 20 games; most of them being my version of other game and a few my own creations. The fact that the computer was slow made one learn how to develop programming techniques that were fast and small. This later proved to be of value as I later progressed to other computer systems. I loved my TI. I still have the old cassette tapes with the programs on them ~ about over 10 of them; its hard to trash them even though I don't use the TI any more. Any TI game programmers out there? It hit me one day when on my PC; "Todays computers don't come with a programming language so you can create something quick to do what you need!?!" I miss those days.

16 bit processor with a 4 bit bus. Somebody at TI should have been shot!

I believe it was an 8 bit bus ...

Good to see this piece of home computing history hasn't been forgotten. I started BASIC programming on one of these when they first came out in the UK.

The one feature which I've never forgotten was that the joystick wouldn't register an "up" command when the caps lock was on. I sent back 4 of the buggers (or rather my increasingly red-faced and impatient father did on my behalf, as I was about 12 at the time) before we noticed the corelation. The support staff at TI and the dealers/retailers didn't have the first clue about this little quirk, however. They probably had thousands of perfectly good joysticks shipped back to them and replaced at great expense before they dropped the system like a stone. Pity.

I got this machine for Christmas in '81 when I was 11, and I used it incessantly. My uncle had written a few programs for it (saved to cassette), and I remember my parents swiping the machine periodically when they had friends over so they could play this horse-racing game he had programmed.

One odd thing I recall was, if you put a regular audio cassette into the cassette player hooked up to it, you could then play the cassette with the sound coming out of the tv speakers! Hey, for me this was high-quality sound reproduction :)

I did a lot of varied programming with it, but mostly creating my own text-adventure games with it. I knew I had to upgrade when, after sitting and typing for no more than an hour creating one of these games, I ran out of memory :(

Man did my sister and I play some games on that thing... we played and played... until the weeee hours of the morning. I beat hunt the wompus! Forget Atari, this thing rocked, and no one else on the block had one. I think my dad tried to teach us basic on it but we laughed at him... and asked him to pop in a game cartrige.

I new this computer in 1987. It was the computer used in my secondary school to teach basic. It may be because they were already a little old but I got a very bad impression from them, they had a lot of features but they were so complicated to use that it was as if they did not have them , the basic was incredible slow, and the harware was unstable (just an small unwanted kick on one of the computer´s table legs and the system hanged). I also remember the function+= problem, I reseted the computer many times when trying to type a "+". The requirement of cartridges was also not practical, one for the basic, one to operate the disc, one... I was really much more satisfied with the CBM 128 I had at home, eventhoug this was a "slower" 8bit computer.

I had a 99/4A as a kid and spent many hours fiddling with it. At the time, it seemed people either had an Apple or a TI as their home computer. I remember many "debates" about which was better - Apples or TIs. One particularly novel difference was that TIs actually had different graphical representations for capitol O's and zeroes while Apples used the same graphics for both.
We eventaully got the Disk Expansion Unit, a big box with a 5 1/4" floppy drive and several expansion slots. We also go a RAM expansion card - all expansion cards were fully encased in plastic and slid down into bus slots. It was all very well designed and looked like something out of 2001 Space Odyssey :)
The most impressive thing I remember, though, was the speech synthesizer used with the game Parsec. Whenver I saw a TI 99/4A demo, that's what they showed. And it was REALLY cool at the time.
We eventually sold it at a yard sale (a few years after we got our first IBM PC compatible).

My dad waited outside in the rain for two hours to get one of the last of these. It's where I learned BASIC. Almost 20 years later, I'm taking BASIC in Computer Science and acing it due to this computer which I used to program when I was 11...

I was a TI employee in Dallas, TX when the 99/4A was a hit. I spent huge dollars purchasing the console and all the expansion modules (remember the expansion box with the firehose connector?) by having Employee Sales deduct the payments from my paycheck. I remember paying something like $300 for a 32K metal-encased memory card for the thing. What killed this computer was that TI was selling the consoles at a loss, hoping to make it up in cartridge software sales. The Commodore 64 had an open architecture that let third-party vendors sell software for the thing- that killed the 99/4A in my opinion. I did like the Extended basic and Multiplan software, however...

The Texas Instruments User Group UK is STILL in exsistance after 20years.
Why not join us at http://tiug.mansfield-notts.co.uk
We have hardware and software for sale plus support and workshops. (ie 30 november 2003 NEC)

This was my first ever computer way back in 1982. I didn't have a tape recorder for a year, so spent days typing in small programs, playing them, then having to lose them all when I turned the PC off.

1 year later I got the speech synthesiser and Parsec and Alpine Climber (if that's what it was called) and Extended Basic.

I still have this computer, boxed, with all the software, manuals and stuff.

Without this little baby, I'd never have got into programming.

Jason M. Hirst
.Net Software Developer

This was my first computer back in 1985, it was a gift from my grandpa. I loved the noise when you turn it on. It was great..
It came with a big book and lots of proggraming examples, noises, weird things that you can do with this great computer. We had chess, and munchman.
I still have the main TI-99, but not sure if it works. I´ll try today to turn it on.

ti owner (IL): if you are wondering about making a video cable for the TI, have a look here: http://web.infoave.net/~compdr/videocable/video.htm. You can find DIN5 plugs (male) on older PC keyboards.

This fabulous computer was way ahead of its time, with a full-sized QUERTY keyboard, with proper keystroke "feel". I was a member of the TIUG of the UK,and I eventually became the custodian of the software library for the User's Group. If anyone wants to contact me, I shall be only too glad to reply. It was most disappointing when Texas withdrew its backing for the TI99/4A, in the early 80's.

This computer was one of my first experiences with computing. It was our first home computer when I was a child and from the age of seven, I have never forgotten this machine. My dad liked it so much at the time that over the course of a few years he had bought three or four of the machines. He sold at least two of them in garage sales but I know he still has at least one in storage that could very well be operational.

Everything about the thing, from the start-up screen, to the voice modulator, to the joy-sticks, to the games and educational software I grew up on, the little TI that could was and shall remain a supreme classic.

This was our very first computer. We had a voice synthesizer, extended basic and many other programs. My son was writing programs for this when he ws 8 or 9 years old. Both of my sons used this a great deal (Mom too) My elder son is now pursuing a career in computers (IT) and my younger son still has the TI-99. Not sure if it still works . We picked up another, plus some additional equipment at a yard sale some years ago, with all of it, I'm sure it could be made functional. Our next computer , some years later , was an Amiga 1000

Graphics wise, this machine was way ahead of it's time. The video processor chip supported up to 32 hardware controlled sprites. The programmer defined shape, direction, speed and layer. The processor handled the rest. This made game prgramming VERY easy on the Ti-994A.

It all started with a TI-99/4A demo unit at a JC Penney's in 1982. I was 2 years old and instantly became infatuated with this machine. My parents bought one for $229 that Christmas, as well as the speech synth unit (my mom thought it was "creepy") and a load of modules. The TI-99 taught me how to write BASIC programs around the same time it was teaching me basic grammar. It was one of the earliest catalysts of creativity in my life. It was the stepping stone to the world of computers, in which I now make my living at the age of 22. I lost my TI-99 in 1986 when my parents auctioned it off and bought an IBM XT, but I plan to acquire another one. Foolish sentimentalism I suppose. So be it! The TI-99 was a fantastic machine, to which I owe much of my success today.

16 bit processor with a 4 bit bus. Somebody at TI should have been shot!

I still have my TI-994A with expansion box, monitor, but no vocal synthesizer or acoustic coupler. It's been a long time since I fired it up to play a few text adventures.... Have the 32 kb expansion card and the 90 kb floppy drive. It was a great unit...

My first home computer was a TI99 4A. You had to hook it up to your TV to have a monitor. I learned to program in Basic using it. I think it was in the 80's, can't remember for sure. The first computer I worked on (programmed) at work was a Bendix G-15 which is in the Smithzonian Musem in D.C. Of course I am retired now (have been for 6 yrs.) from a Computer career (mostly mainframes). I have had several desktop computers since the TI99.

I can recall years of joy programming on this in elementary school and junior high. Perhaps the coolest thing about this machine was easy to program sound. We used to write all sorts of cool 'techno' music and add it to sprite based mini animations. nostalga time

A great little machine in it's idiosyncratic way. i had the extended basic cartridge, and it was one of the best basics on a micro - with fortran like subroutines. And the hardware sprites were great fun to play with. Also the ‘mini memory’ could store programs without the hassle of loading and saving to tape. Finally the 16 bit processor: 9900 machine language with its registers in memory and ‘branch and load workspace pointer’ was so much more sophisticated than the hodge podge of the z80 command set, so common in machines like the Spectrum. Such a shame Texas couldn’t market the thing...

Hi! It was my first computer too! in 1982 :) During all these years, I have never forgot it: it stays preciously near me in my desk. In 1999, I decided to make a homage to this computer and I created the web site: TI-99 Forever! where also can be found informations about the TI-99/4, TI-99/2, TI-99/8, Geneve9640 , CC-40 and others...
To make my site even more complete
, I search all things about the TI-99 family computers (disks, tapes, cartridges, manuals, books, magazines, expansion card, accessories,... ALL !) I have some items to exchange (about 80 cartridges and books)

My very first home computer. I recently rediscovered it through the MESS emulator and have got the retro computing bug! If anyone in the UK has any old TI related hardware, books, software, mags, etc.. please get in touch as I'm looking for stuff to collect.

The TI99/4A. My very first personal computer. I was five. I remember programming this computer and getting it to play music through basic. I will always remember Parsec, TI Invaders, Chisholm Trail, other games for this computer, and the slew of educational software, all of which and including the computer my grandfather got for me. Any more of this and I'll shed a tear.