Texas Instruments TI-99/4

Texas Instruments released the TI-99/4 home computer with 16K RAM, 26K ROM, and a built-in TI-BASIC interpreter, positioning it as a high-end personal computer centered on Solid State Software command modules for instant program access.

The TI-99/4 arrived as a fully assembled home computer with 16K bytes of programmable memory and 26K of read-only memory, expandable to a total of 72K ². It featured a library of Solid State Software command modules (ROM cartridges that provided immediate access to applications without loading delays) ⁴. These modules ranged from educational titles like Early Learning Fun and Beginning Grammar to business tools such as Home Financial Decisions and Investment Analysis, each priced between $19.95 and $69.95 ⁴. The system included TI-BASIC, a 13-digit floating-point implementation described as a "powerful extended BASIC programming language" in early promotional materials ²⁴.

A 13-inch color video monitor was included with the system, supporting sixteen colors for graphic display, though exact resolution, text-mode capabilities, and graphics modes are absent from surviving documentation ²⁴. Audio output delivered a "wide range of sound effects," though no technical specifications for sound generation are recorded ⁴. Optional peripherals included a Solid State Speech Synthesizer, advertised with notable emphasis and sold separately ². Remote controls were available as accessories, each featuring a 360-degree rotary lever and side-mounted pushbutton, allowing two to be connected simultaneously ⁴.

Storage expansion relied on external devices: a Disk Memory Drive retailed for $499.95, while an RF modulator was priced at $49.95 ¹⁰. The system supported a printer, RS-232 interface, and telephone coupler (modem), the latter retailing at $224.95 ⁴¹⁰. A 32K Memory Module was offered as an add-on for $399.95 ¹⁰. Software on floppy disk included adventure titles like Adventureland, The Count, and Pyramid of Doom, all priced at $29.95, while Car Wars appeared as a command module at $39.95 ⁵¹⁵. The Pirate Adventure package shipped in dual formats, floppy disk and command module, at the same $29.95 price point ⁵.

Marketing materials from 1980 list the TI-99/4 system at $1150 ⁴, while other contemporary sources cite a $950.00 retail price ⁶¹⁰ or an "Our Price" of $999 ². A 1982 advertisement lists a "TI 99 4/A" with RF modulator at $199.95, but this refers to the later TI-99/4A model and not the original TI-99/4 ¹. The surviving documentation does not specify the CPU used in the TI-99/4, though later models like the TI-99/4A used the TMS 9900 16-bit processor, a detail not confirmed for this earlier variant ³. Similarly, no operating system is named in the available sources, nor are dimensions, weight, keyboard layout, or expansion bus architecture described.

The TI-99/4 served as the foundation for specialized software packages, including the Invoice Management system, which required the base computer, disk drive, RS-232 interface, an 80-column printer, and either the Personal Record Keeping or Statistics command module ¹². Despite its high initial cost and limited documented technical transparency, the machine emphasized plug-in usability over user-modifiable firmware or low-level access. Its design prioritized immediate functionality through proprietary cartridges, a strategy that constrained software flexibility but simplified operation for non-technical users. The absence of cassette interface details, combined with the premium pricing of peripherals, suggests a deliberate focus on disk-based and cartridge-driven workflows from launch.

References

1. 1982 12 BYTE 07-12 Game Plan 1982 (1982)
2. 1980 05 BYTE 05-05 Floppy Disks (1980)
3. ComputingToday198211 (1982)
4. 1980 01 BYTE 05-01 Domesticated Computers (1980)
5. Byte Magazine Atari Articles
6. 1981 07 BYTE 06-07 Energy Conservation (1981)
7. Interface Age-1981-06 (1981)
8. Invoice Management PHD5027 (1980) manual (1980)
9. BYTE Vol 07-05 1982-05 Japanese Computers (1982)