Texas Instruments TI-99/4A

Texas Instruments' TI-99/4A was a home computer built around a 16-bit TMS 9900 processor and shipped with 16K RAM and a full-size typewriter-style keyboard, offering colour graphics and a built-in version of TI BASIC.

The TI-99/4A featured the TMS 9900, a 16-bit microprocessor at a time when most home computers relied on 8-bit architectures¹⁵. Despite this technical advantage, reviewers noted that in practice, a user "would not be able to distinguish in operation between the Texas and any 'ordinary' 8-bit machine"¹⁰¹¹. The machine came standard with 16K of RAM¹⁰¹¹¹⁵ and included a full-size, standard typewriter keyboard. This design was unusual among contemporaries, which often used membrane or chiclet-style keys¹⁰¹¹¹⁵.

Graphics were described as "16 colour, high resolution"¹⁵, though surviving documentation does not specify exact pixel dimensions. TI BASIC was built into ROM and included enhanced commands for colour control, giving it an edge in accessibility for graphical programming¹⁰¹¹¹⁵. Additional languages such as Extended BASIC, UCSD-PASCAL, TI-LOGO, and Assembler were available, with development tools like the Editor Assembler and Pascal Development System offered by Texas Instruments¹⁵¹⁶.

Expansion was handled through a Peripheral Expansion System designed to hold up to seven peripherals without additional cabling¹⁵. This included support for disk drives, RS232 interfaces, and a speech synthesiser, marketed as giving the computer a voice¹⁵. Notably, the system did not include a tape recorder in the base price¹⁰¹¹, and a fully equipped setup could require no fewer than eight separate boxes, including the television¹⁰¹¹.

The software library reportedly included around 1,000 programs worldwide¹⁵, with titles such as Parsec, Donkey Kong, Burgertime, Alpiner, and Tunnels of Doom¹²⁴. Productivity software included Microsoft Multiplan, TI Writer, and Easy Calc, the latter becoming available in October and usable in the base configuration¹⁴¹⁶. Educational programs covered subjects from BASIC instruction to chemistry and physics¹⁴.

Hardware expansion saw conflicting claims: while Texas Instruments asserted that "there are no second-source Original Equipment Manufacturers of hardware for the TI 99/4A"¹⁶, other sources confirm third-party production by Percom Data (disk drives), A J International (RS232 interfaces), CompuTech Distributing (Winchester disk systems), and Foundation (128K RAM cards)⁵⁶. This suggests either a strategic misrepresentation or a lag in official recognition of the aftermarket.

Pricing varied across markets. In the UK, the system with 16K RAM was priced at around £300¹⁰¹¹, while another source cited a price of approximately £200¹⁵. Despite the discrepancy, reviewers acknowledged the value: "For its asking price, the TI 99/4A offers a great deal – a full-size keyboard, colour output, good BASIC, good expansion possibilities, etc, etc."¹⁰¹¹. Sales were reportedly increasing at the time of Texas Instruments' announcement to discontinue production¹², with expectations that third-party companies would fill any resulting gaps¹².

The machine attracted criticism for limited program availability compared to rivals, though what existed was considered high quality¹⁰¹¹. Enthusiasts dismissed it. "The whizz-kids will condemn it nonetheless!"¹⁰¹¹ Yet its combination of 16-bit processing, colour graphics, and expandability made it a curious outlier in the early 1980s home computer landscape. At least nine books were published to support users, including THINGS TO DO WITH YOUR TI-99/4A COMPUTER and SAMS TI-99/4A GRAPHICS AND SOUNDS³.

Specifications

References

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5. micro 66 nov 1983[ocr] (1983)
6. MICRO Vol66-11 83
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10. Personal Computing Today Aug 1982 (1982)
11. Personal Computing Today Aug 1982 (1982)
12. Carolina8312
13. ComputerPersoenlich 83 13
14. ComputerPersoenlich 83 19
15. ComputingToday198211 (1982)
16. MICRO Vol63-08 83