Texas Instruments Home Computer: TI-99/4A

Last Updated on August 4, 2023 by Dave Farquhar

Texas Instruments was supposed to dominate the home computer market in the 1980s. And on paper they had a good product. But things didn’t work out the way they were supposed to for the Texas Instruments home computer, the TI-99/4A. And that’s why you probably don’t hear as much about it as you’d think you would.

TI entered the personal computer market in 1979 and had some success in the early 1980s. But Apple’s former management literally doesn’t remember competing with it. But for a couple million people in the late 70s and early 80s, the TI provided their first experience with a home computer, and any home computer, however flawed, was something special then. So it provided some fond memories for people of a certain age.

The Texas Instruments TI-99/4A

TI’s first model, the TI-99/4, had some serious shortcomings. It had a terrible membrane keyboard and no lowercase letters. It was also expensive. So the second Texas Instruments home computer, the TI-99/4A, remedied that, adding a full-travel keyboard and small capital letters for mixed case.

TI had the goods. TI dominated consumer electronics in the 1970s with its calculators. Since TI made its own chips, it had lower overhead than most of its competition. Observers fully expected TI to do the same thing to the computer industry that it had the calculator industry: Put out a compelling product, and use its vertical integration to undercut companies like Apple, Atari, and Radio Shack in price. TI was late to the game in 1979, but not too terribly late.

Initial promise

What they brought to the game was compelling. TI’s home computer had a 16-bit CPU in an era when everyone else was still using 8-bit CPUs. They had a video chip that could do bitmapped and sprite graphics in color, which made arcade-style video games much easier to write. They had a sound chip that could play three sounds at once, when most competing machines just had a simple beeper.

It could be a serious computer, since it had a keyboard and memory and you could connect storage devices and a printer to it. And it could play games. The only other company that had a computer that could compete with it head to head in 1979 was Atari. But Atari didn’t have TI’s vertical integration. If TI engaged Atari in a price war, Atari couldn’t win. And TI had successfully marketed electronic educational toys like the Speak and Spell. TI hired Bill Cosby as a celebrity pitchman and the future looked bright.

How an old rival sunk the Texas Instruments home computer

One of TI’s competitors in the home computer field was Commodore. TI and Commodore had been partners and competitors in the calculator market in the 1970s. Commodore bought chips from TI until TI decided to undercut Commodore in price. Commodore in turn bought a struggling chip manufacturer so it could try to duplicate TI’s vertical integration. Engineers at that chip maker convinced Commodore to let them design a personal computer.

So when word got out that TI wanted to enter the computer field, Commodore knew exactly what to expect. And Commodore hit back with the VIC-20, which was a color computer for less than $300. It wasn’t as capable as the TI-99/4A in some ways, but it undercut TI’s price by hundreds of dollars. Every time TI cut prices, Commodore matched it, eventually drawing TI into a situation where it was selling its machines at a loss.

TI didn’t cut the price of its peripherals, however, possibly hoping to make up the profit margins there. But Commodore’s peripherals were also cheaper than TI’s. And TI peripherals all plugged into the side of the machine, which got unwieldy after a couple of upgrades. Commodore’s design was more flexible.

Then in 1982, Commodore released the Commodore 64. It boasted 64K of memory at a price of $595, which was revolutionary in 1982. Its graphics and sound chips could match the TI-99/4A. The C-64 was more expensive, but it also had better profit margins. After about a year of fighting a two-front war against the VIC-20 and C-64, TI gave up.

TI and software developers

TI also had restrictions on software development. Its successful competitors had no such restrictions. When Atari released a handful of titles for other machines, including TI, Apple, and Commodore, TI changed its ROM to block the Atari titles. The other companies welcomed the Atari library. It meant Atari wasn’t the only computer you could play Pac Man on anymore.

It probably didn’t help that TI’s CPU was rather different from the competition, and was awkwardly implemented. To save costs, TI took some shortcuts with the system RAM, which hurt the machine’s performance. The MOS 6502 and Zilog Z-80 CPUs its competitors used weren’t perfect, but they were well understood. Making matters worse, TI supplied little system documentation and was late with delivering it. Developers who wanted to support the machine didn’t necessarily have what they needed in order to do it.

So it wasn’t long before the competition had a bigger software library than TI.

TI’s retreat

In 1983, TI announced it was going to discontinue the TI-99/4A. At $99, the machine sold well in spite of its soon-to-be orphan status. In the end, by March 1984 when TI exhausted its inventory, it had sold 2.8 million units. But profits matter at least as much as units shipped, and TI found profits elusive.

The TI-99/4A maintained a cult following for many years afterward, as hobbyists figured out how to program the machine. Independent development for it continued for a good number of years, including a device to add IBM compatibility to the TI-99/4A. Sort of. And it retains a cult following today, as retro computers surge in popularity.

What could have been

TI stopped selling home computers of its own, but the chips it used in the TI-99/4A soon found their way into other companies’ products. Coleco paired TI’s graphics and sound chips with the more conventional Z-80 CPU in its very successful Coleco Vision video game console and its Adam home computer. Variants of TI’s chips also found their way into the Sega Master System video game console. Microsoft used TI’s graphics chip in its MSX computer design that it licensed to various hardware manufacturers. And IBM used TI’s sound chip in the PCjr, which led to Tandy using the same chip in the extremely successful Tandy 1000, the machine that finally beat the Commodore 64.

If TI had been less restrictive about software development, and if they’d used something resembling a more conventional 8-bit CPU, it’s easy to imagine a Texas Instruments home computer doing well. TI even had a Z80-like CPU design, the TMC1795, from a failed 1971 project that they could have dusted off and revised if they didn’t want to buy someone else’s CPUs.

Other companies were successful with that formula, and the notable exception, the Coleco Adam, was unsuccessful due to reliability problems and being late to market, not anything wrong with TI’s chips. If TI had released something resembling the Adam in 1979 without the production issues, it would have been much harder to compete with.

Texas Instruments home computer value and scarcity

I used to find TI-99/4As at garage sales frequently, usually in their original box, even 25 years after their release. They were about as plentiful as the Commodore VIC-20. The peripherals other than TI’s speech synthesizer module are scarce, but the computer itself is not. The going rate for a Texas Instruments TI-99/4A on Ebay is around $50. Units in good working order can go for somewhat more.