Texas Instruments TI-99/8

The TI-99/8 was an advanced successor to the 99/4A developed around the faster TMS9995 processor, expanded memory, improved BASIC and a redesigned console. It was engineered to remain broadly compatible with the TI home-computer ecosystem.

The system reached an advanced prototype and documentation stage but was cancelled when Texas Instruments left the home-computer market. It shows how far the company intended to develop its proprietary 99 architecture.

Notable Features

• Faster TMS9995 processor
• Substantially expanded memory and improved built-in BASIC
• Compatibility provisions for TI-99/4A cartridges and peripherals

Historical Significance

• The system reached an advanced prototype and documentation stage but was cancelled when Texas Instruments left the home-computer market. It shows how far the company intended to develop its proprietary 99 architecture.

Collector’s Notes

• Only a small number of prototypes survive; boards, firmware and case details vary between development units.
• Memory, storage, displays and expansion hardware should be documented because configurations often changed during a system’s working life.

Specifications

Technical Information
Name	Texas Instruments TI-99/8
Manufacturer	Texas Instruments
Launched	Saturday, January 1, 1983
Country	United States
CPU	Texas Instruments TMS9995
Units Sold
Form Factor	Keyboard console prototype
Power	External power supply
Networking	Planned through expansion
Operating System	Enhanced TI BASIC; planned p-System support
Expansion / I/O	Cartridge, joystick, cassette, Hex-Bus and expansion connections
Keyboard	Integrated full-travel keyboard
Storage	Cartridge and cassette; disk through expansion
Sound	TI SN76489-family three-voice sound plus noise
Colours	16
Graphics	TI TMS9918A video with sprites
Display	Television or composite monitor
ROM	Large ROM/GROM firmware set with enhanced BASIC
RAM	64 KB main RAM plus 16 KB video RAM and system workspace
CPU Speed	Approximately 10.7 MHz