Editing Cambridge Z88

{{refimprove|date=October 2012}}
{{Use dmy dates|date=August 2015}}
{{infobox computer
| image = Cambridge-Z88.jpg
| caption = The Cambridge Computer Z88
| type = [[Notebook (laptop)|Notebook]]
| release date = {{Start date and age|1987|09}}<ref name=becket>{{cite journal | last=Becket | first=Michael | date=September 14, 1987 | url=https://www.newspapers.com/article/the-daily-telegraph-frill-a-minute-stuff/146695190/ | title=Frill-a-minute stuff from Sinclair | work=The Daily Telegraph | page=20 | via=Newspapers.com}}</ref>
| discontinued = 
| processor = CMOS Z80A @ 3.2768&nbsp;MHz
| memory = 32&nbsp;[[kilobyte|kB]] RAM, 128&nbsp;kB EPROM or ROM (internal memory) as standard
| OS = [[OZ (operating system)|OZ]]
| display = 640 x 64 integrated LCD display
| memory card = Proprietary RAM, EPROM or flash cards
}}

The '''Cambridge Z88''' is a [[Zilog Z80|Z80]]-based [[Notebook (laptop)|notebook computer]] released in 1987<ref name=becket /> by [[Cambridge Computer]], the company formed for this purpose by [[Clive Sinclair]]. It was approximately [[A4 paper size]]d and lightweight at {{convert|0.9|kg|abbr=on}}, running on four [[AA batteries]] for 20 hours of use.<ref>{{cite journal | last=Cummings | first=Stephen E. | date=January 23, 1989 | url=https://link.gale.com/apps/doc/A7273649/GPS?sid=wikipedia | title=Products: Cambridge Z88 | work=PC Week | publisher=Ziff-Davis | volume=6 | issue=3 | page=81 | via=Gale}}</ref><ref>{{cite journal | last=Mackintosh | first=Hamish | date=November 28, 2001 | url=https://www.theguardian.com/technology/2001/nov/29/onlinesupplement | title=Memory man | work=The Guardian | page=4 | archiveurl=https://web.archive.org/web/20140510094816/https://www.theguardian.com/technology/2001/nov/29/onlinesupplement | archivedate=May 10, 2014}}</ref><ref>{{cite journal | last=Miller | first=David B. | date=January 1991 | url=https://link.gale.com/apps/doc/A9391180/GPS?sid=wikipedia | title=The Z88: what good things come in | work=DEC Professional | publisher=1105 Media | volume=10 | issue=1 | page=80 ''et seq''. | via=Gale}}</ref>

It was packaged with a built-in combined [[word processing]]/[[spreadsheet]]/[[database]] application called ''PipeDream'' (functionally equivalent to a 1987 [[BBC Micro]] ROM called [[Acornsoft]] View Professional),<ref>{{Cite journal|title=Cambridge Z88 review: A Beeb By Any Other Name?|volume=6|issue=7|journal=Beebug|date=December 1987|page=8}}</ref> along with several other [[application software|applications]] and utilities, such as a Z80-version of the [[BBC BASIC]] [[programming language]].

== History ==

The Z88 evolved from Sir [[Clive Sinclair]]'s ''Pandora'' portable computer project which had been under development at [[Sinclair Research]] during the mid-1980s. Following the sale of Sinclair Research to [[Amstrad]], Sinclair released the Z88 through his [[Cambridge Computer]] mail-order company, as he was no longer permitted to use the Sinclair name after the sale. The machine was launched at the ''Which Computer?'' Show on 17 February 1987.<ref>{{Cite news |date=April 1987 |title=Clive's new Z88 |pages=87 |work=Sinclair User |issue=61 |url=https://archive.org/details/Sinclair_User_061/page/86/mode/2up}}</ref> Early models were contract-manufactured by [[Thorn EMI]] but production later switched to [[SCI Systems]] in Irvine, Scotland.<ref>{{Cite news |date=September 3, 1987 |title=SIR CLIVE SWITCHES Z88 TO SCI FROM THORN |work=Tech Monitor |url=https://techmonitor.ai/technology/sir_clive_switches_z88_to_sci_from_thorn}}</ref>

== Design ==
[[file:CambridgeZ88.jpg|thumb|The 8-line LCD display used by the Z88]]

The Z88 is a notebook computer weighing {{convert|0.9|kg|abbr=on}}, based on a low-power [[CMOS]] version of the popular [[Zilog Z80]] [[microprocessor]]. It comes with 32&nbsp;[[kilobyte|kB]] of internal pseudo-static [[random-access memory|RAM]] and 128&nbsp;kB of [[read-only memory|ROM]] containing the [[operating system]] (called ''OZ''). The memory can be expanded up to 3.5&nbsp;[[Megabyte|MB]] of RAM, the contents of which are preserved across sessions. An integrated capacitor prevents the Z88 from losing its data for the limited time it takes to change the batteries.

The machine uses a [[membrane keyboard]], which is almost silent in use; an optional electronic "click" can be turned on to indicate keystrokes. The Z88 is powered by four [[battery (electricity)#common battery sizes|AA batteries]], giving up to 20 hours of use. It has three memory card slots, which accommodate proprietary RAM, [[EPROM]] or [[flash memory|flash cards]], the third slot being equipped with a built-in EPROM programmer. Card capacities range from 32&nbsp;kB to 1&nbsp;[[megabyte|MB]].

The Z88 has a built-in eight-line, 64 × 640 pixel [[super-twisted nematic display]] which has greater contrast than conventional [[twisted nematic]] LCDs.

The 64&nbsp;kB addressable by the Z80 processor are divided in four banks of 16&nbsp;kB each. The maximum memory of 4&nbsp;MiB for the system is also divided in 256 segments of 16&nbsp;kB each. The hardware can map any of the 16&nbsp;kB blocks to any of the four banks. The first 512&nbsp;kB are reserved for ROM; the next 512&nbsp;kB are reserved for internal RAM. The next 3&nbsp;MB are assigned to each one of the three memory slots.

== Postmarket upgrades ==
{{original research section|date=August 2019}}
[[file:Cambridge Computers Z88 (44656898264).png|thumb|The stand and port of the Cambridge Z88]]

Since 1998, a 1&nbsp;[[Byte#Multiple-byte_units|MiB]] [[Flash memory]] card is available which provides convenient [[non-volatile memory|non-volatile]] storage. Once written to the card, files are safe and not reliant on a power supply. Unlike traditional EPROM cards (erased with an external [[ultraviolet]] light), this one can be electrically erased in the computer's slot. The first generation of card only worked in slot 3 where a 12&nbsp;[[volt|V]] signal (Vpp) is available. The later generation is based on [[Advanced Micro Devices|AMD]] chips and runs with 5&nbsp;V for erasure. It is possible to read, write and erase flash cards in the three slots and the internal one.

It is also possible for an experienced user to replace the built-in 32&nbsp;kB RAM chip with a bigger 128 or 512&nbsp;kB [[Static random-access memory|static RAM]] chip. However, the latter requires some extra board modifications, and 512&nbsp;kB is the biggest size that can be addressed by the Z88 for the internal RAM. A similar modification is possible for the internal ROM slot. A 512&nbsp;kB flash chip can replace the original ROM, allowing an upgrade of the operating system.

==Reception==
[[Jerry Pournelle]] in February 1989 described the Z88 as "the most portable computer I've ever seen", much more so that his [[Zenith SupersPort]] 286. He said that the screen was small but readable, and thought that his $894 estimate for a minimum configuration was "not a ''lot'' of money for good hardware". Pournelle said that Pipedream was "disappointingly hard to use", reported that all of his notes in the software from [[COMDEX]] had vanished because he did not explicitly save them to memory card, and suggested that the Z88 was best suited as a second computer for students and reporters.<ref name="pournelle198902">{{Cite magazine |last=Pournelle |first=Jerry |date=February 1989 |title=Ready Line Overload |url=https://archive.org/details/eu_BYTE-1989-02_OCR/page/n175/mode/2up?view=theater |access-date=2024-10-08 |magazine=BYTE |pages=121-137}}</ref>

== See also ==

* [[Dot space]]
* [[Exact space]]

== References ==

{{refs}}

== External links ==

* [https://www.flickr.com/photos/9574086@N02/sets/72157600856913881/ Rick Dickinson's "Pandora to Z88" gallery on Flickr]
* [http://www.worldofspectrum.org/z88forever/ Z88 Forever enthusiast site]
* [http://www.berget.st/z88 New home for the above algonet.se pages]
* [http://johnallen.com/z88/book.html PipeDream book]
* [http://st-news.com/issues/st-news-volume-4-issue-1/serious/cambridge-computer-z88/ Z88 review, 1989]

{{Sinclair computers and clones}}
[[Category:Computer-related introductions in 1987]]
[[Category:Early laptops]]
[[Category:Sinclair computers and derivatives|Z88]]
[[Category:Z80-based computers]]