UPDATED · 3 OCTOBER 2026

Retro · Nostalgia

TI-99/4A — the 16-bit pioneer that was ahead of its time

Published 3 June 2026Updated 3 October 2026Author KAGAMI Ltd.⏱ ~10 min read

In June 1979 Texas Instruments showed the TI-99/4 in Chicago, and it reached the shops in October. It was a computer with a 16-bit processor at a time when almost all its rivals were 8-bit. The improved TI-99/4A came out in 1981 and was sold at a loss, and at the end of 1983 the company gave up on home computers; about 2.8 million machines had been shipped by the time production stopped. Here is what we know for certain — and what in the old version of this article was not true.

Retro 1979–1984 For everyone

UPDATED · 3 OCTOBER 2026 · WHAT WAS UPDATED

Price of the 4A: ~~“$525 after the price war”~~ → $525 is the starting price at launch in 1981, under half the price of the TI-99/4; in 1983 the price fell to about $99. [3][7]
Release of the 99/4: ~~“in June 1979 it launches the TI-99/4”~~ → shown at CES in June 1979, on sale from October 1979, $1,150 together with a 13-inch monitor. [3][4]
Graphics: ~~“256×192 for the TI-99/4”~~ → the 256×192 bitmap mode belongs to the 4A (TMS9918A chip); the original 99/4 has the earlier TMS9918 with character graphics only. [4][8]
Speed: ~~“in theory twice as fast as the 6502”~~ → removed; in one test TI BASIC is about twice as slow as Apple II BASIC. [7]
Speech synthesizer: ~~“1982”~~ → the date has not been checked and was removed; the chip is from the TMS52xx family (first the TMS5200), not simply the TMS5220. Removed: the invented game lines and “Star Trek”. [5][7][9]
Games: ~~Munch Man “a Pac-Man clone”~~ → inspired by Pac-Man, but the player fills in the maze. ~~Hunt the Wumpus “1980 · Texas Instruments”~~ → a game from 1973 by Gregory Yob; the date and publisher of the TI version have not been checked. [10]
TI-99/8: ~~“an unreleased prototype · a true 16-bit machine”~~ → about 150 prototypes, officially cancelled in October 1983; the clock speed is 10 or 10.7 MHz depending on the source. [6][7]
Sales: ~~“~2.8 million by 1984”~~ → 2.8 million units were shipped by the end of production in March 1984. [7]
Removed: “the children were enchanted”, “Parsec becomes a hit” and other unsourced judgements. Added: a “Sources” section, a timeline with checked dates and a code example that works.

01 · IN BRIEFWhat the TI-99/4A is

Texas Instruments was the largest semiconductor maker in the world in the late 1970s, and its home computer is built around its own TMS9900 processor [7][11]. The TI-99/4 is widely described as the first home computer with a 16-bit processor [7]; this claim rests on a secondary source, which is why we write “widely described”. The competitors in this class — Apple II, TRS-80, Atari and Commodore — were 8-bit.

Specification	TI-99/4A	Source
Introduction / sale	99/4: June 1979 (CES, Chicago) / October 1979 · 99/4A: 1981 (May–June, sources differ)	[2][3][7]
Processor	TMS9900, 16-bit, 3 MHz	[7][11]
Memory	256 bytes of “scratchpad” RAM and 8 KB of system ROM on the 16-bit bus; 16 KB of video RAM behind the video chip; official expansion with 32 KB	[1][7]
Graphics	TMS9918A: 256×192 bitmap, 15 colours plus transparent, 32 sprites (at most 4 on one line)	[7][8]
Sound	up to 3 tones and 1 noise at the same time	[1]
Launch price	99/4: $1,150 with monitor · 99/4A: $525	[3][7]
Sales	2.8 million shipped by the end of production (March 1984)	[7]

ℹ

Why a monitor in the box

The American FCC rejected TI’s RF modulator because the company submitted it without the computer itself. So the 99/4 was sold with a 13-inch colour monitor — a rebadged Zenith television without a tuner — and that raised the price to $1,150 [3][4].

02 · THE PROCESSOR16 bits through an 8-bit bus

The TMS9900 is a single-chip version of the TI-990 minicomputer [7]. The processor is 16-bit, but TI did not redesign the 8-bit chips around it. Only 256 bytes of RAM and 8 KB of system ROM sit on the 16-bit bus; the main memory and almost all the support chips are on the 8-bit side, and that RAM is managed by the video chip and handed over only when the video chip is not using it [7]. Programs and data are read in two steps, which according to a former TI microprocessor manager takes away the advantage of the 16-bit processor [7].

The registers are in memory. The TMS9900 keeps its register sets in RAM and switches context with just one pointer — an inheritance from minicomputers. That is why the fast 256 bytes are valuable: programmers put their working registers there [7].
The GPL language. The software on the cartridges is written in “Graphic Programming Language” — a compact intermediate language that the processor interprets [7]. This saves memory but loses speed.
The lock-out. Consoles marked “V2.2” (made from August 1983) do not accept cartridges from third-party manufacturers without a TI licence, for example from Atarisoft [7].

03 · VIDEO AND SOUNDThe chip that lives on in MSX

The graphics are the work of the TMS9918A — a TI video chip that the company also sold to other manufacturers [7][8]. It uses its own 16 KB of memory and talks to the processor over an 8-bit bus [8]. The fixed palette has 15 colours plus transparent; the chip supports 32 single-colour sprites, but at most 4 on one line [7][8].

The family of this chip is also used in the ColecoVision, the SG-1000 and the MSX standard [7][8] — which is why retro computers of that time often look familiar. The 256×192 bitmap mode is only on the 4A; the original 99/4 with the TMS9918 chip has no bitmap graphics, and that is why some later games, such as Parsec and Alpiner, do not run properly on it [4][7].

“A maximum of three tones and one noise can be activated simultaneously.”
TI-99/4A User's Reference Guide, 1981 [1]

That is the whole sound palette: the TMS9919 chip is an equivalent of the SN76489, which was also used in other systems [7].

04 · BASICTI BASIC and Extended BASIC

The console has TI BASIC built in — an interpreter modelled on Dartmouth BASIC; for the 99/4 it was written by Microsoft under contract [3][7]. It is itself written in GPL and is therefore slow: in one test it runs at about half the speed of Apple II BASIC [7]. Sprites require Extended BASIC, which is sold as a module [7]. The example below is for Extended BASIC.

TI Extended BASIC · character, sprite and sound

10 CALL CLEAR
20 CALL SCREEN(2)
30 CALL CHAR(65,"3C4299A1A199423C")
40 CALL SPRITE(#1,65,16,100,100)
50 CALL MOTION(#1,10,5)
60 CALL SOUND(500,440,0,554,2,659,4)
70 GOTO 70

✎

What the code does

Line 30 defines a character from a hexadecimal pattern, line 40 shows it as a sprite, line 50 moves it, line 60 plays a three-tone chord (frequencies 440, 554 and 659 Hz). Line 70 keeps the program running; you stop it with FCTN + 4. The sound command follows the TI manual [1].

05 · SPEECHThe computer that talked

TI was one of the pioneers of speech synthesis with LPC chips, with which it made the Speak & Spell toy [9]. For the TI-99/4 and 4A a peripheral was sold — a synthesizer that plugs into the side of the console [5][7]. Its chip is from the TMS52xx family: first the TMS5200 with an 8-bit input, later replaced by the TMS5220 [9]. The vocabulary is small and built in [5][7].

The peripheral does not speak by itself. A module with the matching software is also needed — Speech Editor, Terminal Emulator II or another module with speech [1].
The initial idea was small cartridges to extend the vocabulary, but the success of Terminal Emulator II, with its software text-to-speech conversion, cancelled it [5][7].
Towards the end of the machine’s life the synthesizer was given away free with the purchase of several cartridges [5][7].
The command CALL SAY says a word from the vocabulary; words outside the vocabulary are spelled out letter by letter [5].

06 · THE GAMESAbout a hundred titles, most of them from TI

About 100 games came out for the TI-99/4A, most of them from Texas Instruments itself [7]. Critics considered them mediocre — TI did not license popular arcade games such as Zaxxon and Frogger and refused outside developers [7].

Game	Date · publisher	What has been checked	Source
Parsec	1982 · TI	A horizontally scrolling shooter; authors Jim Dramis and Paul Urbanus; uses the speech synthesizer	[10][7]
TI Invaders	1981 · TI	A Space Invaders clone; part of the TI Arcade Game series	[10]
Alpiner	1982 · TI	Climbing six mountains, from Mount Hood to Everest; speaks in a male and a female voice; price $39.95	[10][7]
Munch Man	1982 · TI	Inspired by Pac-Man, but the hero leaves a trail and the goal is to fill in the maze	[10]
Tunnels of Doom	31 Dec 1982 · TI	An underground maze inspired by Dungeons & Dragons; 1–4 heroes; author Kevin Kenney	[10]
Hunt the Wumpus	1973 · Gregory Yob	A text game with caves, ported to many systems, including the TI-99/4A; the date and publisher of the TI version have not been checked	[10]

07 · THE MODELSFrom the TI-99/4 to the never-produced TI-99/8

Model	Year	Processor	Feature	Source
TI-99/4	1979	TMS9900, 3 MHz	Calculator-style keyboard, $1,150 with monitor; TMS9918 video chip without a bitmap mode; fewer than 20,000 sold by the summer of 1981	[4][7]
TI-99/4A	1981	TMS9900, 3 MHz	Typewriter-style keyboard, TMS9918A, $525	[7]
TI-99/4A “V2.2” / “QI”	1983	TMS9900, 3 MHz	Fewer chips (the “QI” board), a beige plastic case, a lock-out against third-party cartridges	[7]
TI-99/8	1983	TMS9995, 10–10.7 MHz	64 KB RAM, built-in speech synthesizer; about 150 prototypes; cancelled in October 1983	[6][7]

08 · TIMELINERise and fall

When	What happens	Source
June 1979	TI introduces the TI-99/4 at CES in Chicago	[3][4]
October 1979	Deliveries begin; $1,150 with a 13-inch monitor	[3][4]
1981	The TI-99/4A is released for $525, with a full-travel keyboard; sales of the 99/4 stay under 20,000	[2][7]
1981–1982	The price falls through $449.95 and $399.95 to about $200 after a $100 rebate for the buyer; a price war with the Commodore VIC-20 begins	[7]
January 1983	Weekly sales reach 30,000, but Commodore cuts prices; TI responds with $150, and in April with $100	[7]
June 1983	In some shops the 99/4A costs $99; TI announces a loss of $100 million for the second quarter	[7]
October 1983	After a loss of $111 million after tax for the third quarter, TI announces it is halting the 99/4A; the remaining stock is sold off down to $49	[7]
March 1984	Production stops; 2.8 million computers have been shipped	[7]

⚠

Why they lose money with so many sales

The computer is much more expensive to produce than the VIC-20, and TI counted on earning from software and peripherals — but it kept them to itself and refused outside developers [7]. A company that sells its main device at a loss, and whose add-ons fail to deliver, loses on both.

09 · THE LEGACYWhat remains

The TI-99/4A became one of the first home computers abandoned by its manufacturer — together with the Coleco Adam, the Mattel Aquarius, the Timex Sinclair 1000 and the IBM PCjr [7]. But it did not disappear: to this day the annual TI Faire is held in Chicago, and the community goes on making new software and hardware [7]. TI’s ideas, such as the video chip with hardware sprites, survive in other machines [7][8].

Galin’s personal opinions and memories are at galin.kagami.bg.

10 · SOURCESSources

Texas Instruments, TI-99/4A User's Reference Guide, 1981 (primary source) — archive.org
Computer History Museum, catalogue record 102647185, “TI 99/4A computer”, 1981 — computerhistory.org
ti994.com, “TI-99/4 Home Computer Timeline” (community archive, secondary) — ti994.com/timeline
ti994.com, “TI-99/4 Home Computer Overview” (secondary) — ti994.com/overview
Ninerpedia, “Speech” (community wiki, secondary) — ninerpedia.org/wiki/Speech
Ninerpedia, “TI-99/8” (secondary) — ninerpedia.org/wiki/TI-99/8
Wikipedia, “TI-99/4A” (secondary) — en.wikipedia.org/wiki/TI-99/4A
Wikipedia, “TMS9918” (secondary) — en.wikipedia.org/wiki/TMS9918
Wikipedia, “Texas Instruments LPC Speech Chips” (secondary) — en.wikipedia.org/wiki/Texas_Instruments_LPC_Speech_Chips
Wikipedia, articles on the games Parsec, TI Invaders, Munch Man, Alpiner, Tunnels of Doom and Hunt the Wumpus (secondary) — en.wikipedia.org/wiki/Parsec_(video_game)
Wikipedia, “TMS9900” (secondary) — en.wikipedia.org/wiki/TMS9900

Checked on 3 October 2026. The primary source [1] was reviewed for sound, memory and speech; most dates, prices and sales figures rest on secondary sources, which is why the page carries an “updated” label and not “verified”.

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