TI(ny) Is A New Take On The TI-99/4A

Way back in the 1980s, in the heyday of the personal computer revolution, Texas Instruments were one of the major players. The TI-99/4A was one of their more popular machines, selling 2.8 million units after an epic price war with the Commodore VIC-20. However once it had been discontinued, fans were left wanting more from the platform. Years later, that led [Fabrice] to produce the TI(ny), his take on an upgraded, more integrated TI-99/4A (Google Translate link).

Having spent many years working on these machines, [Fabrice] was very familiar with the official TI schematics – regarding both their proper use and their errors, omissions and inaccuracies. With a strong underlying knowledge of what makes a TI-99/4A tick, he set out to pen his own take on an extended model. [Fabrice] rolls in such features as Atari-compatible joystick ports, slot connectors for PeBOX expansion cards, and an RGB video output. It’s then all wrapped up in a very tidy looking case of somewhat unclear construction; it appears to be modified from an existing small computer case, and then refinished to look almost stock.

The best detail, though? It’s all made with components available in 1983! We see a lot of retro builds that are the equivalent of throwing a modern fuel-injected V8 into a vintage muscle car, and they are fantastic – but this is a project that shows us what was possible way back when.

Overall it’s a tidy build that shows what the TI-99/4A could have been if it was given a special edition model at the end of its life. If you’re looking to relive the glory days of the machine yourself, what better way then firing up the best demo on the platform? As the saying goes – Don’t Mess With Texas.

[Thanks to g_alen_e for the tip!]

20 thoughts on “TI(ny) Is A New Take On The TI-99/4A

  1. I have quite an experience involving the TI-99/4A. I was in 2nd grade in 1985 in Palm Springs, California. Our school had a modular building set up with about 15 TI99/4A’s. About 5 of them had color TV’s for screens. The rest were black and white TV’s. We all had books with printed BASIC programs that we could choose programs to type in and hope they worked. I chose one that reversed anything you input (it was fun for finding out our names backwards) while others had, well… others. Eloquent, I know. One of the others happened to be a graphics program of some sort that also happened to be on one of the color sets. When the student ran it, it displayed a bunch of colors in quick succession. Suddenly our teacher was on the floor, convulsing!

    Of course many years later I find out that rapid flashing colors can make epileptics have seizures. I am fairly certain this phenomenon was unknown in 1985. At any rate, it was quite an experience, and I credit that very day at school for making it so that I just *HAD* to have a computer. Two years later I did, a Tandy TRS-80 CoCo3 complete with tape recorder storage, and 3 years later my Dad sold his soul to his employer so I could have a $3300 cutting edge 286/12! How times have changed, and yet in some ways they’re ever the same. Rapid color changes still give epileptics seizures, for example.

    1. That makes good sense. I was 8 back then so I was unaware of that at the time. And it was very late and I was very tired when I wrote the above, so I didn’t bother to research it. I knew you guys would correct me ;-)

    1. Additional comment: the “Teach Yourself Basic” book also introduced me to the “data” feature of Basic. I was thrilled when I realized I could program in the actual ASCII codes of the letter cubes from the game “Boggle” and display realistic Boggle boards up on the screen! ????

    1. TI saved a few cents* per console by using a single DE9 connector for the Wired Remote Controllers. All the lines to both sticks are in common, except the common line for each stick is separate. Inside the sticks there’s a diode on every line except the common line.

      *Or perhaps it was to force people to buy TI’s joysticks.

      When accessing the port, the computer polls the Up, Down, Left, Right lines and watches for connection to the two separate common lines.

      But they made one goof in their design. The joystick port is in there with the keyboard and having Caps Lock on interferes with the Up line. When Caps Lock is on it blocks the computer from sensing any Up input from either stick. The fix for that is wiring a diode to the bottom of the Caps Lock key.

      Diagrams for all this are freely available online.

      Way back when, I made my own dual Atari to TI stick adapter using DB25 and DE9 connectors and shells. I took the TI sticks apart and used an ohm meter’s continuity test to ring the connections. Then I bought 10 small diodes at the local Radio Shack and got to soldering. To adapt the DB25 to two DE9 plugs I cut and glued a small pine trapezoid into the middle of the connector. Instead of a multi wire cable between the connectors I just made the wires long and wrapped with a bunch of electrical tape.

      Why use a DB25 instead of separate DE9’s to plug the sticks in? Saved a couple of dollars. I was also able to crimp and solder the diodes directly to the insert pins.

      What prompted that project was TI’s sticks were simultaneously super stiff and mushy, and I was tired of getting my pinky finger tip pinched between the bottom of the handle and the top of the controller base. Tombstone City is nigh impossible with TI’s crappy sticks.

      I also built my own joystick using pieces salvaged from a plexiglass window from a horse trailer to make the case (hooray for superglue and Bondo!), four microswitches salvaged from a couple of old vacuum tube color televisions, various bits of scrap wood, a decorative cup washer, a fender washer and a spherical headed flat blade screw from a cabinet latch. Using that screw with its head sandwiched between the cup and fender washers made the switch action adjustable by turning the screw to adjust the handle height. I could tighten it down until the barest twitch would close a switch (essential for killing it in Tombstone City) or loosen it for games that required a bit less reaction speed. The only pieces I bought for the stick was a pair of momentary switches for a fire button on each front corner, wired in parallel. To keep the handle from rotating I drove a long screw into one side and held it between a pair of screws driven vertically into the plywood base. The case was painted a light blue metallic, the handle a dark blue metallic.

      I wish I hadn’t let that stick go when I traded all my TI stuff for four brand new 1 megabyte 30 pin SIMMs so many years ago, when that sort of RAM cost an arm and a leg. I’ve been thinking about re-creating it. I still have some of those cabinet latches that haven’t been used.

      I did have a couple of other Atari compatible sticks I’d picked up at thrift shops, but my homebrew one was much better, with the exception of not having a thumb button or trigger button on the handle.

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