My story ...

A look back at the time when the ZX80, ZX81 & SPECTRUM

In the beginning there was the ZX80 ...
I was working as a GP in Lincoln when I got my ZX80 and I still remember assembling the kit on a friend's sitting room floor. The computer fortunately worked immediately. But what to do with it was still uncertain. However, the ZX80 was really the first computer that allowed you to find out how it worked, and very quickly I started to understand what it could do, and just how it did it. A few weeks later, I saw an advert from Bob Maunder, a lecturer in Middlesborough, who wanted programs to use in his college. We spoke on the phone and it was apparent that I already knew a lot about how the ZX80 functioned, so Bob asked me to write a few pages of details for him to show to his students. Following on from this Bob suggested that together with a friend, Terry Trotter, we would produce a book about the ZX80. This became The ZX80 Companion. I also produced The ZX80 Monitor Listing, a partly annotated disassembly of the 4K ROM. Bob then suggested we write three more books. He would write about games programming, Terry Trotter would write about the electronics, and I would write about the operating system. At this time I had stopped being a fulltime GP and has started doing sessional work which allowed me time to prepare a manuscript, under the working title of Understanding Your ZX80 ROM. But as Bob and Terry did not write their books it was decided that I look for another publisher.
Just at the same time Sinclair Research brought out their ZX81; and I was fortunate to get one fairly early. I still remember I was mowing the grass at my local village hall when one of my girls told me there was a phone call from Melbourne, in Australia! The call was from Alfred Milgrom who ran Melbourne House; Alfred was impressed I had a manuscript ready for printing - but it was on the ZX80. So the mauscript was re-written for the ZX81 and the first version of Understanding your ZX81 ROM soon appeared. This was printed with a red cover and had a spiral binding; however there were many printer's errors. Later editions were printed in Australia & Hong Kong. I subsequently produced an annotated disassmbly of the first half of the 8K ROM published as The ZX81 Monitor listing Part A The ZX81 was a great success and computer fairs started to appear in all the big cities. At one fair, I believe at Earl's Court, I met Clive Sinclair, for the one and only time. At another fair I met Frank O'Hara, a statistician, who had worked out how the ZX81 handled its calculations. I still remember he had an exercise book in which he had made copious notes. Frank's explanation of the mathematics was a revelation to me; and soon we were jointly able to produce a disassembly of the second half of the 8K ROM, the Sinclair Z81 ROM Disassembly Part B. After the fairs held on 30 January 1982, there was a gathering organised at a local pub, and I was surprised to be awarded The first Annual Rosetta Stone Award by Mindware Co. of Wayland, MA, USA.

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It was shorlty after when I had my first contact whith Sinclair Research. They asked if I would look at a copy-cat ZX81 from China; this was the Lambda 8300.
I remember going to London and seeing a barrister. He asked me to write a report because Sinclair Reasearch were seeking an injunction in the Hong Kong courts to have the Lambda banned. In my report I pointed out that the ROM code was almost the same as that of the ZX81, and even included the mistakes found in the original. I never heard the outcome of the case, but the Lambda 8300 was sold all around the world under a number of different brand names. I do not think, however, that Clive Sinclair was particulary worried as he had other plans.


It is hard nowadays to understand the excitement that greeted the SPECTRUM. Here at last was a cheap home computer that produced a colour display and sound. Of course there were limitations, but at the price the SPECTRUM was in a class of its own. It was an immediate success. A new book was needed for the new computer, and after a few weeks study I wrote Understanding Your Spectrum. And some time later Frank O'Hara and myself were able to produce The Complete Spectrum Rom Disassembly. Many other books looking at various aspects of the Spectrum were produced by other authors; and it is believed that the growth of the British computer games industry is due in a large part to the facts that the Spectrum was so easy to program and the details of how it worked had been made widely available. The ZX81 had sold in small numbers in the USA, produced under a Timex brand name, but there was a lot of competition and it was not very successful. However, following the launch of the Spectrum, Timex wanted to make its own improved version. But they wanted too many changes, took too long and totally missed the market. I was invited to help with the programming and spent an enjoyable fortnight in Connecticut; but it was very sad to hear just a few weeks later that the project had been halted and the programmers had lost their jobs. Meanwhile, back in Cambridge, the development team at Sinclair Research was still at work. Martin Brennan was writing the program for the Interface-1 and Microdrive; and he asked me to help. Martin had not been on the original Spectrum team, so he was unsure how best to integrate the new code with the old. Over a couple of months, I spent a day each week at Cambridge, whilst working on the coding at home in between.   
Whilst waiting for the actual release of the Interface-1 and Microdrives I did write The Spectrum Microdrive Book. A couple of other small jobs followed. I was asked to write a program to be used to test new Spectrums coming off the production line. And, produce a similar program for the Interface-2 that was to be used by W H Smith shops. The Interface-2 was taken up by a few games companies, but generally the cost of production was considerably higher than the similar cassette tape versions and the Interface-2 did not sell well.

The QL

It was becoming difficult for Sinclair Research at this time. The home computer market was becoming saturated, sales of the SPECTRUM were going down, and Clive Sinclair had failed to get the BBC contract. A new machine was needed and whilst I was visiting Cambridge I met Tony Tebby when he was writing the operating system for a new machine. There was a degree of secrecy but it was clear it was to have a 68000 processor and have microdrives. In due course the QL was launched - but it was not a games machine and the sales were just not good enough.


I really only did one more bit of programming after, and that was a small job for the BBC. They wanted to transmit programs that people could download for themselves at home. The idea was that you got a copy of the appropriate BASICODE program for your computer and then waited for a new program to be transmitted. The whole system did work, but it was dropped after just a few months.


40 years on, it is perhaps easier to see what happened. Clive Sinclair reached the pinnacle of his success with the SPECTRUM. But he did not realise that he should have concentrated on making another games-playing machine, rather that attempt to enter the highly competitive office and business market. The QL was just not good enough. The crash came very suddenly. I was owed a last small expenses account, and Martin Brennan could not arrange payment, with everything being so difficult. In the end we settled with him sending me 2 Sinclair TV's. And that really was the finish. Clive Sinclair took Alan Sugar's cash payment for the company's warehouse stock and the rights to all the trademarks - and the doors at Sinclair Research's lovely Cambrige HQ were closed. And we all went our own ways ....


There are 3 interviews that I have given over the years: 1. 'Popular Computing Weekly' in September 1983 ... larger ...
2. 'Sinclair User' in November 1983.. view ..
3. And recently, '' .. view ..

Revised 3 September 2020