Editing Xerox Star (section)

==Hardware==
Initially, the Star software was to run on a new series of [[virtual memory|virtual-memory]] processors. The D* (pronounced D-Star) series of machines has names beginning with that letter. They are all [[microcode|microprogrammed]] processors; for the Star software, microcode is loaded to implement an instruction set designed for Mesa. It was possible to load microcode for the Interlisp or Smalltalk environments, but these three environments can not run at the same time.

The Dolphin (aka D0), built with [[transistor-transistor logic]] (TTL) technology, included [[74181|74S181]] ALUs. It was intended to be the Star workstation, but its cost was deemed too high for the project goals. The complexity of the software eventually overwhelmed its limited configuration. At one time in Star's development, it took more than half an hour to reboot the system.

The next generation of these machines, the Dorado (aka D1), used an [[emitter-coupled logic]] (ECL) processor. It was four times faster than Dandelion on standard benchmarks, and thus competitive with the fastest super minicomputers of the day. It was used for research but was a rack-mounted CPU that was never intended to be an office product.<ref name="dorado">{{Cite journal|author=Pier|first=Kenneth A.|year=1983|title=A retrospective on the Dorado, a high-performance personal computer|url=http://bitsavers.org/pdf/xerox/parc/techReports/ISL-83-1_A_Retrospective_on_the_Dorado_A_High-Performance_Personal_Computer.pdf|journal=ACM SIGARCH Computer Architecture News|volume=11|issue=3|pages=252–269|doi=10.1145/1067651.801663|access-date=January 26, 2019}}</ref> A [[Router (computing)|network router]] called Dicentra is based on this design.

The released Star workstation hardware is called Dandelion (often shortened to "Dlion"). It is based on a design from in a PARC technical report, ''Wildflower: An Architecture for a Personal Computer'', by [[Butler Lampson]].<ref>{{cite web |url=http://research.microsoft.com/Lampson/Systems.html|title=Systems|website=Butler Lampson's Microsoft Research site|archive-url=https://web.archive.org/web/20080511202455/http://research.microsoft.com/Lampson/Systems.html|archive-date=May 11, 2008|url-status=dead}}</ref> It is based on the [[AMD Am2900]] [[bitslice microprocessor technology]]. An enhanced version of the Dandelion, with more microcode space, was dubbed Dandetiger.

The base Dandelion system has 384&nbsp;[[Kilobyte|KB]] [[Computer storage|memory]] (expandable to 1.5&nbsp;MB), a 10&nbsp;MB, 29&nbsp;MB or 40&nbsp;MB 8" hard drive, an 8" [[floppy drive]], mouse, and [[Ethernet]]. The performance of this machine, which sold for {{US$|20,000|1981|round=-3}}, is about 850 in the [[Dhrystone]] benchmark — comparable to that of a [[VAX-11]]/750, which cost five times more. The {{cvt|17|in|cm}} [[cathode-ray tube]] (CRT) display (black and white, 1024×808 pixels with 38.7&nbsp;Hz refresh<ref>{{Citation |mode=cs1
 | date = 1985–1987
 | title = Xerox 8010/40 Document creation system brochure
 | location =Uxbridge, Middlesex
 | publisher = Rank Xerox
 }}</ref>) is large for the time. It can display two 8.5×11 in pages side by side in true size. The overscan area (borders) can be programmed with a 16×16 repeating pattern, to extend the root window pattern to all the edges of the monitor.

The D-Star machines were commercialized as:
* Dolphin: Xerox 1100 Scientific Information Processor [[Lisp machine]], (1979)
* Dorado: Xerox 1132 Lisp machine
* Dandelion: Star, Xerox 1108 Lisp machine (1981)
* Dandetiger: Xerox 1109 Lisp machine
* [[Xerox Daybreak|Daybreak]]: Xerox 6085 Star successor, Xerox 1186 Lisp machine (1985)