Popular Computing Weekly (20K) Front cover game - and less than 400 bytes!


Nowadays, I'm lucky to have time to keep up with the trailing edge of technology but fifteen years ago I had a few things published and could write machine code routines in the time it now takes me to put together a web page. If the early eighties seemed like a golden era to you too then join me on a trip down memory lane.


Enter Clive Sinclair

Apart from writing a few lines of BASIC on one of the teletype "timeshare" terminals at school my first taste of computing was a ZX81. I'd been hooked on Space Invaders for some time and fancied writing some games, so sent off my 50 pounds for a kit when Sinclair launched his second "proper" computer. Of course, I had to wait about four months for it to arrive, and after about eight weeks a friend, Eamon, bought a ready-built one from W. H. Smiths, and then got bored enough with it to lend it to me for a few weeks. Eamon's mate, who'd been on a computer course said nothing useful could be done with a 1KB machine, but armed with the book "Mastering Machine Code on your ZX81" by Toni Baker.ZX81 I managed to write a version of Space Invaders that just about fitted into 1KB. Two tricks made this possible:-
  1. Use of self modifying code (where the routine changes itself during run-time!)
  2. Using alternative screen lines instead of a whole screen. (The video display RAM was part of your 1KB!)
Want to know more about the ZX81? Then try the ZX81 Home Page

Lucky Break No. 1

When my machine arrived I gave Eamon his back, along with a tape of the game. He worked for BT and was fitting a phone system for a new start-up computer magazine, and being a good mate, got them to look at my game. With so little available for the ZX81, they decided to publish it, which is how I got my first game on the cover of a magazine, and gave me some very good contacts. I began writing the odd article for Popular Computer Weekly. And then came:-

Lucky Break No. 2

Another friend, Chris, got hold of one of the first Sinclair Spectrums to come out, and then got sent away on a residential training course, so he lent it to me! I wrote a game, mainly in BASIC, but with a machine code routine at the core to speed it up and sent it off to the magazine for possible publication which lead to:-

Lucky Break No. 3

Duncan at PCW was looking for some software to publish on cassette - we polished up the game and I re-wrote all the BASIC in machine code to make it harder to copy, took it along to W. H. Smiths, and they placed an order for it! Cruising On Broadway (16K)There was hardly any Spectrum software around at the time, but I was flattered to read on the net recently that "Cruising on Broadway" just managed to scrape into Your Sinclair's all-time top 100 games at 96! If you fancy a game then you can download it in one of two forms - running on a Spectrum Emulator or as a DOS (only!) compiled C program. You will find them in my Download area. Want to know more about the Spectrum? Then here is a link to The World of Spectrum

Taking coals to Newcastle

Sunshine - the parent company of PCW - were making more money from books than software and had links with Timex, who had bought the rights to Sinclair technology in the US, so they asked me to write a book about the Timex Sinclair 2000 - the American Spectrum - called "Inside Your TS 2000" and convert Cruising on Broadway. The game was to be renamed Crossfire. The conversion would have been simple except:-
  1. They wanted the game on ROM cartridge
  2. The printer and sound ports were different
  3. They couldn't let me have a machine!
The game was published, the book was printed, and then Timex pulled out of the computer market.

Inside your Spectrum

Inside Your Spectrum (10K) Despite being surrounded by computers, Portuguese Book (9K) the Timex book was written on a typewriter with the help of my girlfriend Diane Rogers, so a lot of retyping was needed to produce the Spectrum version. My favourite book is the Portuguese translation.


Taxi! (16K)Before moving on to more complex machines, I had a go at a game that I had thought up while trying to drive to work one day. Originally called "DangerVans" after those red Post Office vans that still drive around like idiots, you were a taxi driver who had to work Hammersmith Broadway. Written for the Spectrum, and capable of running on a 16KB machine, I sent it to Digital Integration, who asked me to make it harder to play before publishing it. I think it sold about 20 copies - that's what the royalty statement said - so imagine my surprise to find it on the Internet! You can download an emulator version of it in my Download area - there is a bug if you forget to refuel which I don't remember in the version I tested and I now think its actually too hard to play - one day I might re-write it (for Windows 2002?) - less red vans, less fuel consumption and additional screens - any comments?

Dragon 32

Cruising I bought a Dragon 32 to use as a word processor, but ended up doing a conversion of Cruising for Sunshine. It sold just enough copies to pay for the computer, by which time I had a QL, so I sold the Dragon. Great machine code on the 6809 chip! There are a couple of good emulators for the Dragon (helped by the fact that it was very similar the Tandy Color Computer) and I have found an image of Cruising for the Dragon on the internet. If you want to find out more about the Dragon then here is a link. I've put the Cruising file in my Download area.
Sinclair QL (2K)

Clive's Nemesis - the QL.

I never really liked the QL. Sunshine gave me an early one and it didn't live up to expectations - the microdrives could be as slow as tape cassettes (or so it felt) and it was late, bugged and not as fast as they made out. I had a go at 68000 machine code, and even wrote an "Introduction to the Hardware" book, but it was never as good as I thought it would be. If you loved you QL then we will agree to differ - and here is a link!

Amstrad CPC 464

This was the first truly practical home computer that I owned - once I added a disc drive (199 pounds!). Diane used it for years as a word processor. I also liked writing machine code on it (the good old Z80 again) and wrote "Mastering Machine Code" which was mainly a collection of utility routines. It also had some of the best documentation available of any of the home computers. Is there a web site dedicated to it? Yes, here!

Bigger is better?

Today, writing software is a structured, clinical process; it should always have been, but the early computers were so simple that you could write stuff in raw code that even you didn't stand a chance of understanding the next day but it worked and was fast. Hardware improvements and vast amounts of RAM and hard disc space mean that there is no need for speedy or compact programs - "Just buy this compiled BASIC program, a new CPU and another 64MB of RAM Sir". Mind you, computers are a lot more useful today - just not as much fun!

My Download Area

PC Games you can Download from here
GameOriginal ComputerNeeds Emulator?SizeClick to DownloadNotes
Cruising on Broadway Spectrum No 12KB cruisepc.zip PC Turbo C Version
Cruising on Broadway Spectrum No 37KB cruisewa.zip Compiled Emulator
Cruising on Broadway Spectrum Yes 6KB cruisz80.zip .Z80 Snapshot
Cruising on Broadway Spectrum Yes 5KB cruistap.zip .TAP File
Cruising on Broadway Dragon Yes 7KB cruised.zip .CAS file
Taxi! SpectrumNo40KB taxi!wa.zip Compiled Emulator
Taxi! SpectrumYes9K taxi!z80.zip .Z80 Snapshot
Spectrum emulator links - Z80 V.3.05 (shareware) or Warajevo V.2.0
Dragon emulator link - T3