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 The Cambridge Computer Z88 | |
| Type | Notebook |
|---|---|
| Release date | September 1987; 38 years ago (1987-09)[1] |
| Operating system | OZ |
| CPU | CMOS Z80A @ 3.2768 MHz |
| Memory | 32 kB RAM, 128 kB EPROM or ROM (internal memory) as standard |
| Removable storage | Proprietary RAM, EPROM or flash cards |
| Display | 640 x 64 integrated LCD |
TheCambridge Z88 is aZ80-basednotebook computer released in 1987[1] byCambridge Computer, the company formed for this purpose byClive Sinclair. It was approximatelyA4 paper sized and lightweight at 0.9 kg (2.0 lb), running on fourAA batteries for 20 hours of use.[2][3][4]
It was packaged with a built-in combinedword processing/spreadsheet/database application calledPipeDream (functionally equivalent to a 1987BBC Micro ROM calledAcornsoft View Professional),[5] along with several otherapplications and utilities, such as a Z80-version of theBBC BASICprogramming language.
The Z88 evolved from SirClive Sinclair'sPandora portable computer project which had been under development atSinclair Research during the mid-1980s. Following the sale of Sinclair Research toAmstrad, Sinclair released the Z88 through hisCambridge Computer mail-order company, as he was no longer permitted to use the Sinclair name after the sale. The machine was launched at theWhich Computer? Show on 17 February 1987.[6] Early models were contract-manufactured byThorn EMI but production later switched toSCI Systems in Irvine, Scotland.[7]
The Z88 is a notebook computer weighing 0.9 kg (2.0 lb), based on a low-powerCMOS version of the popularZilog Z80microprocessor. It comes with 32 kB of internal pseudo-staticRAM and 128 kB ofROM containing theoperating system (calledOZ). The memory can be expanded up to 3.5 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 amembrane keyboard, which is almost silent in use; an optional electronic "click" can be turned on to indicate keystrokes. The Z88 is powered by fourAA batteries, giving up to 20 hours of use. It has three memory card slots, which accommodate proprietary RAM,EPROM orflash cards, the third slot being equipped with a built-in EPROM programmer. Card capacities range from 32 kB to 1 MB.
The Z88 has a built-in eight-line, 64 × 640 pixelsuper-twisted nematic display which has greater contrast than conventionaltwisted nematic LCDs.
The 64 kB addressable by the Z80 processor are divided in four banks of 16 kB each. The maximum memory of 4 MiB for the system is also divided in 256 segments of 16 kB each. The hardware can map any of the 16 kB blocks to any of the four banks. The first 512 kB are reserved for ROM; the next 512 kB are reserved for internal RAM. The next 3 MB are assigned to each one of the three memory slots.
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Since 1998, a 1 MiBflash memory card has been available which provides convenientnon-volatile storage. Once written to the card, files are safe and not reliant on a power supply. Unlike traditional EPROM cards (erased with an externalultraviolet 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 V signal (Vpp) is available. The later generation is based onAMD chips and runs with 5 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 kB RAM chip with a bigger 128 or 512 kBstatic RAM chip. However, the latter requires some extra board modifications, and 512 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 kB flash chip can replace the original ROM, allowing an upgrade of the operating system.
Jerry Pournelle in February 1989 described the Z88 as "the most portable computer I've ever seen", much more so than hisZenith SupersPort 286. He said that the screen was small but readable, and thought that his $894 estimate for a minimum configuration was "not alot of money for good hardware". Pournelle said that Pipedream was "disappointingly hard to use", reported that all of his notes in the software fromCOMDEX 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.[8]
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| Amstrad | ||
| Licenced systems | ||
| Timex Corporation | ||
| Cambridge Computer | ||
Lists ofclones | ||
Compatible or related systems |
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| Sinclair Research peripherals | ||
| Timex peripherals |
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| Other peripherals | ||
| People | ||