Tandy Color Computer 3

The Tandy Color Computer 3 introduced the GIME video and memory controller, 128KB RAM and an effective 1.79 MHz 6809E while preserving much earlier CoCo software. RGB monitor output and 80-column text made it suitable for more serious applications.

With OS-9 Level II and memory expansion to 512KB, the CoCo 3 was the most capable production member of Tandy’s 6809 family.

Notable Features

• Motorola 6809E at 1.79 MHz with 128KB standard; expandable to 512KB.
• The principal display was Television, composite or RGB monitor; 32, 40 or 80-column text.
• Storage support consisted of Cassette, cartridge and optional floppy or hard-disc storage.

Historical Significance

• With OS-9 Level II and memory expansion to 512KB, the CoCo 3 was the most capable production member of Tandy’s 6809 family.
• Radio Shack’s large retail network made demonstration, sales and support available well beyond specialist computer dealers.

Collector’s Notes

• Factory memory, drive configuration and regional badge should be checked because many surviving systems were upgraded.
• Original monitors, manuals, software, storage hardware and Radio Shack peripherals add historical context.

Specifications

Technical Information
Name	Tandy Color Computer 3
Manufacturer	Tandy
Launched	Tuesday, July 1, 1986
Discontinued	1991
Launch Price	$219.95
Country	United States
CPU	Motorola 6809E at 1.79 MHz
Units Sold
CPU Speed	1.79 MHz with 0.895 MHz compatibility mode
RAM	128KB standard; expandable to 512KB
ROM	32KB Extended Color BASIC 2.0 ROM
Display	Television, composite or RGB monitor; 32, 40 or 80-column text
Graphics	GIME graphics up to 640 x 225 in four colours or 320 x 225 in sixteen colours
Sound	Six-bit DAC with software audio and cartridge sound options
Storage	Cassette, cartridge and optional floppy or hard-disc storage
Keyboard	Integrated full-travel keyboard
I/O	RGB, composite/RF, cassette, serial, joysticks and cartridge expansion
Operating System	Extended Color BASIC 2.0 and OS-9 Level II