Cambridge Z88
From Wikipedia, the free encyclopedia
 |
|
| Cambridge Z88 | |
|---|---|
| Type | Portable computer |
| Released | 1988 |
| Discontinued | |
| Processor | CMOS Z80A @ 3.2768 MHz |
| Memory | 32 KiB, 128 KiB or 512 KiB depending on model |
| OS | OZ |
The Cambridge Z88 was an A4-size, lightweight, portable Z80-based computer with a built-in combined word processing/spreadsheet/database application called Pipedream, along with several other apps/utilities, such as a Z80-version of BBC BASIC.
The machine was designed by Sir Clive Sinclair and released by his company Cambridge Computers in 1987 (Sir Clive having been unable to market the computer as the Sinclair Z88 after selling Sinclair Research's computer business to Amstrad in 1986).
[edit] Technical description
The Z88 is a portable computer based on a low-power CMOS version of the popular Z80 microprocessor. It comes with 32 KiB of internal pseudo-static RAM and 128 KiB of ROM containing the Operating System (called OZ), but can be expanded up to 3.5 MiB of RAM, of which the contents are preserved thanks to the batteries. An integrated capacitor prevents the Z88 from losing its data for a limited amount of time while changing the batteries.
Despite the lightness of the Z88—it weighs 0.9 kg—its construction is surprisingly robust, including its membrane/chiclet keyboard which is both comfortable and almost inaudible (an optional electronic "click" can be turned on if it proves too quiet for the user's taste).
Powered by four AA batteries (giving up to 20 hours of use), the computer has three memory slots; each of which can be used for RAM expansion, removable mass storage, and proprietary program use. Since the slots use RAM, EPROM and ROM for their data transfer, the transfer speeds are usually very high. Although RAM cards of up to 1 MiB capacity were available, they were expensive. Most users used one or two 128 KiB cards.
Though the LCD display has only eight lines, it is clear and surprisingly effective. In Pipedream, a miniature view of a whole page appears to the right of the display, giving a good feel for the overall layout, and compensating for the inevitable "letterbox" effect.
[edit] Living on in the new millennium
The Z88 had something of a cult following, and is still used by a few enthusiasts. A variety of software is available including games and utilities. Also, there is a 1 MiB Flash EEPROM now available which provides convenient non-volatile storage. Once written to the card, files are safe and not reliant on a power supply. Unlike traditional EEPROM cards, this one can be erased and reformatted in the computer.
It is also possible for an experienced user to replace the built-in 32 KiB RAM chip with a bigger 128 or 512 KiB static RAM chip. However, the latter requires some extra board modifications, and 512 KiB is actually the biggest size that can be addressed by the Z88 for the internal RAM.
