Z88, Z88 emulator, and portable computing in the 1980s

Been using this today:

https://cambridgez88.jira.com/wiki/spaces/OZVM/overview

The Z88 was the last computer released by Sinclair Research (using the name Cambridge Computer as Amstrad by then had bought the rights to the Sinclair name.) The Z88 was an A4-paper (that's “Like Letter-size but sane” to 'murricans) sized slab-style laptop computer. By slab-style I mean the screen and keyboard were built into a single rectangular slab, it didn't fold like a modern laptop. It was Z80 based, had solid state memory, and a 640x64 monochrome (supertwist LCD) display which looked gorgeous. There was 32k of battery backed RAM but my understanding is functionality was very limited unless you put in a RAM expansion – other than the Spectrum that was a Sinclair trademark. In classic Sinclair style it had a rubber “dead flesh” keyboard, though there was a justification given, that the keyboard was “quiet” and that was probably legitimately a selling point.

Sir Clive had a dream dating back to the early 1980s that everyone should have a portable computer that was their “main” computer. The idea took shape during the development of the ZX81, and was originally the intended use of the technologies that went into the QL. Some of the weirder specifications of the QL, such as its 512x256 screen being much wider than the viewable area of most TVs, came from Sinclair's original intention to use a custom CRT with a Fresnel lens set up as the main display for the machine. Early on it was found that the battery life of the portable computer designed around the ZX83 chips was measured in minutes, and the idea was discarded. (I believe, from Tebby's account, that the ZX83 chips remained unchanged because they started to have difficulty getting new ULA designs tested.)

So... after selling up to Amstrad, Sinclair tried one last time and made a Z80-based machine. He discarded both Microdrives (which weren't energy efficient, and I suspect belonged to Amstrad at this point) and his cherished flat screen CRT technologies (which were widely criticized) and finally adopted LCDs. And at that point it looks like everything came together. There were still issues – the machine needed energy efficient static RAM which did (and does) cost a small fortune, so the Z88 had limited storage in its base form. Flash was not a thing in 1988, EEPROMs were expensive and limited, but more conventional EPROMs (which used UV light to reset them) were affordable storage options.

So, with a combination wordprocessor/spreadsheet (Pipedream), BASIC, Calendar/clock, and file management tools, the computer was definitely finally useful.

I never got a Z88 as I was still a teenager at the time and the cost was still out of my league. When I got my QL it was 80GBP (on clearance at Dixons) which I just had enough savings for. Added a 25GBP monitor a few months later. But that gives you some idea of the budget I was on during the height of the original computer boom.

Anywho, IIRC the Z88 ended up being around 200GBP and the media was even more expensive, which would have been a hell of a gamble for me at the time given despite Sir Clive's intentions it was far from a desktop replacement. It had limited programmability – it came with BBC BASIC (not SuperBASIC, as Amstrad now had the rights to that) but otherwise development was expensive. And a 32K Z80 based computer in 1988 was fairly limited.

But I really would have gotten one had I had the money. I really loved the concept.

The emulator above comes as a Java package that requires an older version of Java to run. It wouldn't start under OpenJDK 17 (as comes with Debian 12), but I was able to download OpenJDK 6 from Oracle's site (https://www.oracle.com/java/technologies/javase-java-archive-javase6-downloads.html) which ran fine from the directory I installed it into without having to mess with environment variables.

Anyway, a little glimpse into what portable computing looked like in the 1980s, pre-smartphones and clamshell laptops.

See also:

There's also the ill-fated Commodore LCD, a 6502 KERNAL based system designed by Bill Herd. It wasn't a slab, having a fold out screen, but was similar in concept. It was killed by an idiotic Commodore Manager who asked Radio Shack if they should enter the market with a cheap laptop, and who believed the Radio Shack executive he spoke to when said exec told him there wasn't a market. Radio Shack was, of course, selling the TRS-80 Model 100 at the time, and making money hand over fist.

Final comment: these types of slab computer weren't the only “portable computers” in the 1980s. Excluding luggables (which weren't true portables in the sense they couldn't run without a mains power connection), and a few early attempts at clamshell laptops, there were also “pocket computers”. Made mostly by Casio and Sharp, these were miracles of miniaturization, usually with only a few kilobytes of memory at most and a one or two line alphanumeric LCD display. I had a Casio PB-80 which had about 500 bytes of usable memory. (IIRC they called bytes “steps”, reflecting the fact these things were designed by their manufacturer's programmable calculator divisions) They did have full versions of BASIC, and arguably their modern successors are graphing calculators. These devices were nice, but their lack of any communications system or any way to load/save to external media made them limited for anything beyond really simple games and stock calculator functions.