Editing Heathkit (section)

== Personal computers ==
[[File:Heathkit H-8 computer.jpg|thumb|First 8-bit Heathkit H8 computer (1978)]]
Before entering the burgeoning home computer market, Heathkit marketed and sold microprocessor-based systems aimed at learning about this technology. The ET-3400, for example, was released in 1976 and was based on the [[Motorola 6800]] microprocessor. This system included 256 bytes of RAM, a 1k monitor in ROM, and a keypad for easy entry and modification of programs.<ref>{{Cite web |title=Heathkit ET-3400 Trainer - Computer - Computing History |url=https://www.computinghistory.org.uk/det/44383/Heathkit-ET-3400-Trainer/ |access-date=2022-12-14 |website=www.computinghistory.org.uk}}</ref> Despite being a small trainer kit, it was powerful and flexible enough to be used in rudimentary control systems.<ref>{{Cite journal |last1=Milligan |first1=W. Lloyd |last2=Richardson |first2=Anthony |date=1979-03-01 |title=A microprocessor-(Heath ET-3400) based backup control system for laboratory experiments |journal=Behavior Research Methods & Instrumentation |language=en |volume=11 |issue=2 |pages=314–315 |doi=10.3758/BF03205668 |issn=1554-3528|doi-access=free }}</ref>

In 1977, Heathkit introduced the [[Heathkit H8]] home computer. The H8 was very successful, as were the [[Heathkit H19|H19]] and [[Heathkit H29|H29]] terminals, and the [[Heathkit H89|H89]] "All in One" computer. The H8 and H89 ran the Heathkit custom operating system [[HDOS]] as well as the popular [[CP/M]] operating system. The H89 contained two Zilog [[Z80]] 8-bit processors, one for the computer and one for the built-in H-19 terminal.<ref>{{cite news| first = Tom | last = Williams| title = Heathkit to Market Computer Products Through Distributors| journal = [[The Intelligent Machines Journal]]| issue = 9| publisher = Jim C. Warren, Jr.| location = Woodside, CA| quote = The new terminal, the H19, is also built around a Z80 microprocessor,...| date = 1979-06-11| page = 7| url = https://books.google.com/books?id=Gj4EAAAAMBAJ&q=Heath+H19+schematic&pg=PA7| access-date = 2010-02-19}}</ref> The [[Heathkit H11|H11]], a low-end [[Digital Equipment Corporation|DEC]] [[LSI-11]] 16-bit computer, was less successful, probably because it was substantially more expensive than the 8-bit computer line.

By fiscal year 1980 computers were 40% of Heathkit revenue.<ref name="mace19820412">{{Cite magazine |last=Mace |first=Scott |date=1982-04-12 |title=Zenith working on 16-bit micros |url=https://books.google.com/books?id=YjAEAAAAMBAJ&pg=PA3#v=onepage&q&f=true |access-date=2025-03-16 |magazine=InfoWorld |pages=1,4}}</ref> Seeing the potential in personal computers, [[Zenith Electronics Corporation|Zenith Radio Company]] bought Heath Company from Schlumberger in 1979 for $63 million,<ref>Sol Libes ''BYTE News...'' in ''BYTE'', {{ISSN|0360-5280}}, Volume 4 No. 11, November 1979 p. 81</ref>{{r|lawrence19920330}} renaming the computer division '''[[Zenith Data Systems]]''' (ZDS). Zenith purchased Heath for the flexible assembly line infrastructure at the nearby St. Joseph facility as well as the R&D assets.<ref name="BrueschkeMack"/>{{rp|151}}

Zenith opened additional Heath stores after the acquisition.{{r|mace19820412}} Heath/Zenith was in the vanguard of companies to start selling personal computers to small businesses. The WH-89 assembled version of the H-89 kit was re-branded as the [[Zenith Z-89]]/[[Zenith Z-90|Z-90]], an assembled all in one system with a monitor and a [[floppy disk drive]]. They had agreements with [[Peachtree Software]] to sell a customized "turn-key" version of their [[accounting]], CPA, and [[real estate management]] software. Shortly after the release of the Z-90, they released a 10MB [[hard disk]] unit and double-density external floppy disk drives.

While the H11 was popular with hard-core hobbyists, Heath engineers realized that DEC's low-end PDP-11 microprocessors would not be able to get Heath up the road to more powerful systems at an affordable price. Heath/Zenith then designed a dual Intel [[8085]]/[[8088]]-based system dubbed the [[Heathkit H100|H100]] (or [[Zenith Z-100|Z-100]], in assembled form, sold by ZDS). The machine featured advanced (for the day) bit mapped video that allowed up to 640 x 225 pixels of 8 color graphics. The H100 was interesting in that it could run either the [[CP/M]] operating system, or their OEM version of [[MS-DOS]] named [[Z-DOS]], which were the two leading business PC operating systems at the time. Although the machine had to be rebooted to change modes, the competing [[operating system]]s could read each other's disks.

After hinting at a robot at the 1982 [[West Coast Computer Faire]],{{r|mace19820412}} that year Heath introduced the [[HERO (robot)#HERO 1 (ET-18)|Hero-1]] [[robot]] kit to teach principles of industrial robotics.<ref>Steven Leininger ''Heath's HERO-1 Robot'', ''BYTE'', January 1983 pp. 86–96</ref> The robot included a [[Motorola 6800|Motorola 6808]] processor, ultrasonic sensor, and optionally a manipulator arm; the complete robot could be purchased assembled for $2495 or a basic kit without the arm purchased for $999.  This was the first in a popular series of Heathkit robot kits sold to educational and hobbyist users.