Bio-Chip was quite a challenge to program. It was, in all honesty, the most difficult program I have ever written. It took many hours to code and was, at times, a real pain in the butt.

Luckily I had some expert help from one of the best BBC games writers, Peter Scott. Although I have never spoken to Peter personally about writing my game, I have consulted with him often. How? By means of the excellent series of articles which he wrote on the subject of writing games. The articles appeared in the last few issues of Disk User magazine. Although Disk User finished before the series ended, the series will be continued in the brand new disk magazine Fast Access.

If you have always wanted to write a game but thought that it would be too hard then try getting hold of Peter's articles and his advice will make things much easier. I speak from personal experience.

Due to the fact that I have only written two games before, I wanted to do something simple and fun. My first effort was a pitiful BASIC version of Hangman which I still play when I need a good laugh. The more recent is a machine code shoot-'em-up with mono graphics and little else. This time I wanted to concentrate more on presentation, using colour and animation to make the game more interesting.

First of all I sketched ideas and sheets of paper later I decided enough was enough. I had the basic screen layout and some very rough ideas about the look of the game characters.

I used The Sprite System to design the sprites and maze elements. After a lot of editing and re-editing I finally stuck with the present designs. I later scrubbed some of the graphics to save memory. At this point I should mention that I finally ended up wasting huge amounts of memory because of ignoring good advice from Peter. That's life I suppose.

When I had the sprites defined, I simply wrote a BASIC program to design the screen layout. This turned out to be another case of being settled on a particular design but then, with an uncontrollable burst of creativity, re-editing the whole screen. This would be OK if the result was better than the start but often it was a complete mess!

I wish there was a programmer who I could just ask to design all the graphics and screen layout etc. I could then get on with coding the program. Sadly, being a one man team, that was out of the question. My brother, a keen programmer, offered to help me but he took one look at my machine code program and walked away laughing. I took it that I was beyond help.

To cut a very long story short, I finally ended up with a program which was very playable and looked good. The programming may not set any records but it works and has no bugs at all. Hours of play testing by some friends of mine has ensured that.

My final advice is that, if you want to write a good game, then read Peter Scott's articles and stick rigidly to your design specifications. Even if you feel that they are impossible to code, give them a try. You may well surprise yourself about what you are capable of. I know I did. If you have no interest in writing a game then be sensible, just go out and buy Bio-Chip!