The ZX Spectrum Ula: How to Design a Microcomputer

by Christopher David Smith

This book takes the reader through the design and implementation of the Sinclair ZX Spectrum's custom chip, revealing for the first time the decisions behind its design and its hidden secrets. By using it as case study, the techniques required to design an 8-bit microcomputer are explained, along with comprehensive details of the Ferranti ULA manufacturing process. If you have ever wanted to design your own computer or wondered what was behind the most successful microcomputer of the 1980s, then this is the book for you. For the first time, the inner working of the Sinclair ZX Spectrum's custom chip and heart of the computer, the Ferranti ULA, is exposed in minute detail. Packed with over 140 illustrations and circuit diagrams, this book takes the reader through the cutting edge technology that was the Ferranti ULA and the design of the ZX Spectrum home computer, illustrating the principles and techniques involved in creating a cost effective computer that required nothing more than a television set and a cassette recorder. The ZX Spectrum ULA is an essential read for the electronics hobbyist, student or electronic engineer wishing to design their own retro-style microcomputer or anyone with an interest in historical micro-electronic and digital design. All topics are explained in simple yet precise terms, building on their careful introduction towards the full functionality presented by the Sinclair computer. Some of the topics covered The architecture of the standard microcomputer, Ferranti and their ULA, manufacturing process and structure, The functional layout of the ZX Spectrum ULA, Video display generation, Memory contention and timing, ZX Spectrum design bugs such as "The Snow Effect", Hidden features, ULA version differences.

324 pages, Paperback

First published July 30, 2010

Reviews

[Serhiy Dzyubin · Rating 5 out of 5]

Awsom!!! A very deep look at the architecture of this legendary home cumputer ))

[Robert · Rating 5 out of 5]

Fascinating insight into the soul of the ZX Spectrum and the chip that made it so unique.

[Cesare Falco · Rating 5 out of 5]

If you ever wished to know the magic behind the Sinclair ZX Spectrum, you have the Holy Grail at hand. How the author has gathered so many information on a so (until now) obscure custom chip is simply amazing. The book covers possibly all issues of the Sinclair machine and describes in great details how its original design has undergone many revisions through the different issues of each model. And how crucial the ULA by Ferranti was in this neat design.

What surprises me most is how well written the book is. From such a techical text you would expect tons of boring explanations and schemes. The net effect is, you actually get tons of information, but they are not boring at all. They are presented in such a clever and well organized way that you don't need to be an engineer to understand them (and I know very little about electronics). In short: no matter you owned a Speccy back in your teens or not, if you are curious about how a microcomputer is designed, this is an absolute must.

[Carlos Duarte do Nascimento · Rating 5 out of 5]

Awesome book if you had typical contact with a ZX Spectrum (or, with one of its clones, like the Brazilian TK90x in my case) and want to know how it *really* worked inside. Some electronics knowledge helps, but you can learn as it goes or even skip sessions that are too detailed. I have learned a lot about ICs, television signals (in particular PAL, although NTSC is covered as well) and lots of random 8-bit brain candy.