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TRS-80 Color Computer
The TRS-80 Color Computer, later marketed as the Tandy Color Computer, is a series of home computers developed and sold by Tandy Corporation. Despite sharing a name with the earlier TRS-80, the Color Computer is a completely different system and a radical departure in design based on the Motorola 6809E processor rather than the Zilog Z80 of earlier models.
The Tandy Color Computer line, nicknamed CoCo, started in 1980 with what is now called the Color Computer 1. It was followed by the Color Computer 2 in 1983, then the Color Computer 3 in 1986. All three models maintain a high level of software and hardware compatibility, with few programs written for an older model being unable to run on the newer ones. The Color Computer 3 was discontinued in 1991.
All Color Computer models shipped with Color BASIC, an implementation of Microsoft BASIC, in ROM. Variants of the OS-9 multitasking operating system were available from third parties.
Tandy Corporation announced the TRS-80 Color Computer in July 1980 as a low-cost home computer. The Color Computer is a completely different design than the Zilog Z80-based TRS-80 models. BYTE wrote, "The only similarity between [the two computers] is the name".
The TRS-80 Color Computer derives from an "experimental videotext project by the Kentucky Cooperative Extension Service and the University of Kentucky College of Agriculture" in 1977. Motorola Semiconductor of Austin, Texas, won the contract for the user terminals and Tandy's Computer Division joined later to manufacture the terminals. The initial goal of this project, called "Green Thumb", was to create a low cost videotex terminal for farmers, ranchers, and others in the agricultural industry. This terminal would connect to a phone line and an ordinary color television and allow the user access to near-real-time information useful to their day-to-day operations on the farm.
Motorola's MC6847 Video Display Generator (VDG) chip was released about the time the joint venture started. The 1978 prototype "Green Thumb" terminal used the MC6847 and the Motorola 6809 microprocessor. However, the prototype contained too many chips to be commercially viable. Motorola responded by integrating the functions of many smaller chips into one chip: the MC6883 Synchronous Address Multiplexer (SAM). The SAM, VDG, and 6809 were used as the core of the AgVision terminal. It was also sold through Radio Shack stores as the VideoTex terminal around 1980.
The VideoTex terminal provided the foundation for a general-purpose home computer. The internal modem was removed, and I/O ports for cassette storage, serial I/O, and joysticks were provided. An expansion connector was added to the right side of the case for future enhancements and ROM cartridges ("Program Paks"). A sticker indicating the amount of installed memory in the machine covers the hole where the modem's LED "DATA" indicator had been. On July 31, 1980, Tandy announced the TRS-80 Color Computer, which shares the same case, keyboard, and layout as the AgVision/VideoTex terminals.
Tandy viewed businesses as its primary market for computers. Although the company's Ed Juge said in 1981 that the Color Computer was "our entry into the home-computer market", he described it as "for serious professionals", stating that a word processor and spreadsheet would soon be available. The initial model (catalog number 26-3001) shipped with 4 KB of dynamic random access memory (DRAM) and 8 KB Microsoft BASIC in ROM. Its price was US$399 (equivalent to $1,520 in 2024). Within a few months, Radio Shack stores across the US and Canada began selling the new computer.
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TRS-80 Color Computer AI simulator
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TRS-80 Color Computer
The TRS-80 Color Computer, later marketed as the Tandy Color Computer, is a series of home computers developed and sold by Tandy Corporation. Despite sharing a name with the earlier TRS-80, the Color Computer is a completely different system and a radical departure in design based on the Motorola 6809E processor rather than the Zilog Z80 of earlier models.
The Tandy Color Computer line, nicknamed CoCo, started in 1980 with what is now called the Color Computer 1. It was followed by the Color Computer 2 in 1983, then the Color Computer 3 in 1986. All three models maintain a high level of software and hardware compatibility, with few programs written for an older model being unable to run on the newer ones. The Color Computer 3 was discontinued in 1991.
All Color Computer models shipped with Color BASIC, an implementation of Microsoft BASIC, in ROM. Variants of the OS-9 multitasking operating system were available from third parties.
Tandy Corporation announced the TRS-80 Color Computer in July 1980 as a low-cost home computer. The Color Computer is a completely different design than the Zilog Z80-based TRS-80 models. BYTE wrote, "The only similarity between [the two computers] is the name".
The TRS-80 Color Computer derives from an "experimental videotext project by the Kentucky Cooperative Extension Service and the University of Kentucky College of Agriculture" in 1977. Motorola Semiconductor of Austin, Texas, won the contract for the user terminals and Tandy's Computer Division joined later to manufacture the terminals. The initial goal of this project, called "Green Thumb", was to create a low cost videotex terminal for farmers, ranchers, and others in the agricultural industry. This terminal would connect to a phone line and an ordinary color television and allow the user access to near-real-time information useful to their day-to-day operations on the farm.
Motorola's MC6847 Video Display Generator (VDG) chip was released about the time the joint venture started. The 1978 prototype "Green Thumb" terminal used the MC6847 and the Motorola 6809 microprocessor. However, the prototype contained too many chips to be commercially viable. Motorola responded by integrating the functions of many smaller chips into one chip: the MC6883 Synchronous Address Multiplexer (SAM). The SAM, VDG, and 6809 were used as the core of the AgVision terminal. It was also sold through Radio Shack stores as the VideoTex terminal around 1980.
The VideoTex terminal provided the foundation for a general-purpose home computer. The internal modem was removed, and I/O ports for cassette storage, serial I/O, and joysticks were provided. An expansion connector was added to the right side of the case for future enhancements and ROM cartridges ("Program Paks"). A sticker indicating the amount of installed memory in the machine covers the hole where the modem's LED "DATA" indicator had been. On July 31, 1980, Tandy announced the TRS-80 Color Computer, which shares the same case, keyboard, and layout as the AgVision/VideoTex terminals.
Tandy viewed businesses as its primary market for computers. Although the company's Ed Juge said in 1981 that the Color Computer was "our entry into the home-computer market", he described it as "for serious professionals", stating that a word processor and spreadsheet would soon be available. The initial model (catalog number 26-3001) shipped with 4 KB of dynamic random access memory (DRAM) and 8 KB Microsoft BASIC in ROM. Its price was US$399 (equivalent to $1,520 in 2024). Within a few months, Radio Shack stores across the US and Canada began selling the new computer.