Editing Microcomputer (section)

=== TTL precursors ===
Although they did not contain any microprocessors, but were built around [[transistor-transistor logic]] (TTL), [[Hewlett-Packard]] calculators as far back as 1968 had various levels of programmability comparable to microcomputers. The HP 9100B (1968) had rudimentary conditional (if) statements, statement line numbers, jump statements ([[go to]]), registers that could be used as variables, and primitive subroutines. The programming language resembled [[assembly language]] in many ways. Later models incrementally added more features, including the [[BASIC]] programming language (HP 9830A in 1971). Some models had tape storage and small printers. However, displays were limited to one line at a time.<ref>{{cite web|url=http://www.hpmuseum.org|title=The Museum of HP Calculators}}</ref> The [[Hewlett Packard 9100A|HP 9100A]] was referred to as a [[personal computer]] in an advertisement in a 1968 [[Science (journal)|Science]] magazine,<ref>{{cite web|url=http://www.hp.com/hpinfo/abouthp/histnfacts/museum/personalsystems/0021/other/0021ad.pdf |archive-url=https://web.archive.org/web/20060312220318/http://www.hp.com/hpinfo/abouthp/histnfacts/museum/personalsystems/0021/other/0021ad.pdf |archive-date=2006-03-12 |url-status=live |title=Powerful Computing Genie|publisher = Hewlett Packard |access-date=2012-08-30}}</ref> but that advertisement was quickly dropped.<ref>{{cite web|url=http://www.sciencemag.org/cgi/issue_pdf/frontmatter_pdf/162/3852.pdf |archive-url=https://web.archive.org/web/20070621133200/http://www.sciencemag.org/cgi/issue_pdf/frontmatter_pdf/162/3852.pdf |archive-date=2007-06-21 |url-status=live |title=Restoring the Balance Between Analysis and Computation |access-date=2012-08-30}}</ref>  HP was reluctant to sell them as "computers" because the perception at that time was that a computer had to be big in size to be powerful, and thus decided to market them as calculators.  Additionally, at that time, people were more likely to buy calculators than computers, and, purchasing agents also preferred the term "calculator" because purchasing a "computer" required additional layers of purchasing authority approvals.<ref>{{cite web|url=http://www.hp.com/hpinfo/abouthp/histnfacts/museum/personalsystems/0021/0021history.html|title=History of the 9100A desktop calculator, 1968|website=HP virtual museum|access-date=2019-07-19}}</ref>

The [[Datapoint 2200]], made by [[Datapoint|CTC]] in 1970, was also comparable to microcomputers.  While it contains no microprocessor, the [[instruction set]] of its custom TTL processor was the basis of the instruction set for the [[Intel 8008]], and for practical purposes the system behaves approximately as if it contains an 8008.  This is because Intel was the contractor in charge of developing the Datapoint's CPU, but ultimately CTC rejected the 8008 design because it needed 20 support chips.<ref>{{cite web |url=http://www.computermuseum.li/Testpage/MicroprocessorHistory.htm |title=MicroprocessorHistory |publisher=Computermuseum.li |date=1971-11-15 |access-date=2012-08-30 |url-status=dead |archive-url=https://web.archive.org/web/20150923205820/http://www.computermuseum.li/Testpage/MicroprocessorHistory.htm |archive-date=2015-09-23 }}</ref>

Another early system, the [[Kenbak-1]], was released in 1971. Like the Datapoint 2200, it used [[Integrated circuit#SSI|small-scale integrated]] [[transistor–transistor logic]] instead of a microprocessor. It was marketed as an educational and hobbyist tool, but it was not a commercial success; production ceased shortly after introduction.<ref>{{cite web|url=http://www.vintage-computer.com/kenbak-1.shtml|title=Kenbak-1|website=The Vintage Computer|access-date=2006-08-14|archive-date=2011-01-22|archive-url=https://web.archive.org/web/20110122235215/http://www.vintage-computer.com/kenbak-1.shtml|url-status=dead}}</ref>