Editing TRS-80 Color Computer (section)

==History==
[[Image:TRS-80 Videotex terminal retouched.jpg|thumb|250px|TRS-80 [[Videotex|VideoTex]] Terminal, c. 1980]]

[[Tandy Corporation]] announced the TRS-80 Color Computer in July 1980 as a low-cost home computer.<ref name="white198708">{{Cite journal |last=White |first=Ron |date=August 1987 |editor-last=Maloney |editor-first=Eric |title=The Tandy Story |url=https://archive.org/details/80-microcomputing-magazine-1987-08/page/n61/mode/2up |journal=[[80 Micro]] |location=Peterborough, NH |publisher=CW Communications |pages=50–64 |issn=0744-7868 |access-date=April 4, 2023 |quote="[...] the Color Computer was Tandy's answer to the popularity of the Commodore Vic-20 as an inexpensive computer for home use." |via=[[Internet Archive]]}}</ref> 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".<ref name="byte198103">{{cite magazine | url=https://archive.org/stream/byte-magazine-1981-03/1981_03_BYTE_06-03_Programming_Methods#page/n91/mode/2up | title=What's Inside Radio Shack's Color Computer? | magazine=[[Byte (magazine)|BYTE]] | date=March 1981 | access-date=14 June 2014 |last1=Ahrens |first1=Tim |last2=Browne |first2=Jack |last3=Scales |first3=Hunter | pages=90–130 | volume=6 |issue=3 }}</ref>

The TRS-80 Color Computer derives from an "experimental videotext project by the Kentucky [[Cooperative State Research, Education, and Extension Service|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.<ref>{{Cite book|url=https://files.eric.ed.gov/fulltext/ED239585.pdf|title=Information Technology for Agricultural America|publisher=U.S. [[Government Printing Office]]|year=1983|location=Washington, D.C.|pages=327|access-date=2020-07-25|archive-date=2021-02-27|archive-url=https://web.archive.org/web/20210227152310/https://files.eric.ed.gov/fulltext/ED239585.pdf|url-status=live}}</ref> 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.<ref>{{Cite magazine|last=Libes|first=Sol|date=February 1980|title=Motorola, Tandy and Western Union Introduce "Green Thumb" Systems|url=https://archive.org/details/byte-magazine-1980-02/page/n71/mode/2up|magazine=[[Byte (magazine)|BYTE]]|volume=5 | issue=2|pages=70}}</ref><ref name="GreenThumb">{{Cite book|last1=G. Pitre|first1=Boisy|last2=Loguidice|first2=Bill|title=CoCo: The Colorful History of Tandy's Underdog Computer|date=2013|publisher=CR Press|location=Europe|page=19|isbn=9781466592483|url=https://books.google.com/books?id=k5bNBQAAQBAJ&q=tandy+coco+sales&pg=PA81|access-date=16 February 2018|archive-date=12 April 2024|archive-url=https://web.archive.org/web/20240412044620/https://books.google.com/books?id=k5bNBQAAQBAJ&q=tandy+coco+sales&pg=PA81#v=snippet&q=tandy%20coco%20sales&f=false|url-status=live}}</ref> 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 Controller|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.<ref name="ElencoAgVision">{{cite news | url=https://vintagecomputer.ca/agvision-videotex-terminal/ | title=AgVision Videotex terminal | work=Vintage Computer | date=2016-12-22 | access-date=16 April 2018 | archive-date=2018-04-17 | archive-url=https://web.archive.org/web/20180417105537/https://vintagecomputer.ca/agvision-videotex-terminal/ | url-status=live }}</ref>

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 communication|serial]] [[input/output|I/O]], and [[joysticks]] were provided. An expansion connector was added to the right side of the case for future enhancements and [[ROM cartridge]]s ("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.<ref name="freibergerfuture19810831">{{cite magazine | url=https://books.google.com/books?id=rD0EAAAAMBAJ&pg=PA49 | title=Radio Shack Prepares for the Future | magazine=[[InfoWorld]] | date=1981-08-31 | access-date=26 October 2016 | last=Freiberger | first=Paul | author-link=Paul Freiberger | pages=51, 53–54 | volume=3 | issue=17 | archive-date=2024-02-07 | archive-url=https://web.archive.org/web/20240207115519/https://books.google.com/books?id=rD0EAAAAMBAJ&pg=PA49#v=onepage&q&f=false | url-status=live }}</ref> The initial model (catalog number 26-3001) shipped with 4&nbsp;KB of [[dynamic random access memory]] (DRAM) and {{nowrap|8 KB [[Microsoft BASIC]]}} in [[Read-only memory|ROM]]. Its price was {{US$|399|1980|round=-1}}. Within a few months, Radio Shack stores across the US and Canada began selling the new computer.