Texas Instruments TI-99/4A
Also known as TI-99/4A
The TI-99/4 and TI-99/4A are home computers released by Texas Instruments (TI) in 1979 and 1981, respectively. Based on TI's own TMS9900 microprocessor originally used in minicomputers, the TI-99/4 was the first 16-bit home computer. The associated TMS9918 video display controller provides color graphics and sprite support which were only comparable with those of the Atari 400 and 800 released a month later. The TI-99 series also initially competed with the Apple II and TRS-80.
Key facts
- Information appliance.name
- TI-99/4A
- Information appliance.logo
- File:TI-994A logo.svg
- Information appliance.image
- Texas Instruments TI-99-4A (white bg).jpg
- Information appliance.developer
- Texas Instruments
- Information appliance.manufacturer
- Texas Instruments
- Information appliance.type
- Home computer
- Information appliance.discontinued
- March 1984
- Information appliance.cpu
- TMS9900 @ 3 MHz
- Information appliance.graphics
- TMS9918A
- Information appliance.successor
- TI-99/4A
- Information appliance.units_shipped
- 2.8 million
- Information appliance.os
Article
25 sectionsContents
- Features
- Video Display Processor
- Expansion
- Peripheral Expansion Box
- Speech synthesizer
- History
- 99/4
- 99/4A
- Lack of third-party development
- Discontinuation
- Architecture
- Technical specifications
- CPU
- Memory
- Video
- Sound
- Games
- Unreleased hardware
- Hex-Bus
- TI-99/4A successors
- Legacy
- Post-TI development
- See also
- References
- External links
The TI-99/4 and TI-99/4A are home computers released by Texas Instruments (TI) in 1979 and 1981, respectively. Based on TI's own TMS9900 microprocessor originally used in minicomputers, the TI-99/4 was the first 16-bit home computer. The associated TMS9918 video display controller provides color graphics and sprite support which were only comparable with those of the Atari 400 and 800 released a month later. The TI-99 series also initially competed with the Apple II and TRS-80.
The calculator-style keyboard of the TI-99/4 and the high price were cited as weak points. TI's reliance on ROM cartridges and their practice of limiting developer information to select third parties resulted in a lack of software for the system. The TI-99/4A was released in June 1981 with a simplified internal design, full-travel keyboard, improved graphics, and a unique expansion system. At half the price of the original model, sales picked up significantly and TI supported the 4A with peripherals, including a speech synthesizer and a "Peripheral Expansion System" box to contain hardware add-ons. TI released developer information and tools, but the insistence on remaining sole publisher continued to starve the platform of software. Architectural quirks of both models reduced the performance benefits of the 16-bit CPU.