I spent my teenage years playing with electronics - taking things apart, building things and, later, designing things and having the designs published in the hobby electronics magazines that were popular at the time in the UK. I built several Sinclair ZX-80 and ZX-81 kits for friends, but could not afford a computer of my own. Eventually my family bought me a Sharp MZ80K and I was able to get into programming properly. Playing games was never really my interest - I found programming them much more interesting, particularly at the assembler level.
 
One thing I got into was computer chess. There was a book around at the time giving a complete source code listing of Sargon chess in Z80 assembler.

I typed the whole lot in, got it working, added graphics, and then spent many hours modifying and improving it.
 
Another project I worked on was the design for a Z80 computer. I thought I had come up with a new idea - stretching the Z80 clock to control it's access to video memory when the video system also needed to access it.
 
These two things came together nicely when I answered a job advert as a video game programmer for a small company called Intelligent Software. I was only 19, had just finished school and had a university place lined up, studying micro electronics and computer science. At the last minute I decided I didn't want to spend the next 3 years learning what I had already taught myself, so I went for the job interview.
 
I travelled to Store Street, London where IS had a small first-floor office above some shops.


 
I was interviewed by Robert Madge, IS's technical director. Their interview room was actually a corridor connecting the programmer's room to the coffee machine in the kitchen, so it was quite busy! The first person to come through was Mark Taylor, one of their chess wizards, so we had a long in-depth chat about chess programs. Another person to come through was a visitor called Nick Toop, so we had another long chat this time about Z80 clock stretching! (A special and unique feature of the Nick chip, for the non-technical)  How could I not get the job?!

Another programmer around at the time was Richard Lang. He too had started with Sargon Chess and heavily modified it (much more than I had done), resulting in Cyrus Chess, which was available on the Enterprise (and others!) Richard later went on to produce the first chess program ever to beat a chess grand master, Garry Kasparov. More information for anyone interested: http://chessprogramming.wikispaces.com/Richard+Lang

Both Mark Taylor and Richard Lang appeared in the YourComputer Jan 1984 photo: Mark is on the bottom row second from the left, and Richard is on the top row, right most.
 
Another interesting chess product IS worked on at the time was a chess computer that could move its own pieces. It used an XY plotter mechanism beneath the board and an electromagnet could "grab" and move the chess pieces which all had a magnet in the base.
 
EDIT: youtube video of it playing and development story!

But all this was an amusing aside for myself and Martin Lea.I already had the core BASIC working using a character I/O on another system, so while Martin worked on EROS (later to be renamed EXOS) I worked on the Enterprise-specific parts of IS-BASIC. Quite a few unplanned enhancements crept in at this stage, such as the multiple program/CHAIN ability and being able to LIST and RENUMBER by procedure name. The original idea was for EROS and BASIC to live in the internal ROM, but clearly this was not going to happen! That is why the Enterprise has its BASIC in a cartridge.

In my spare time - I'm not sure how I found any! - I wrote FORTH, just for my own interest. Once the managers heard about this it became an official product!

At the time I was just doing what I loved, what gave me a"kick" and what often made me go to the office in the morning without bothering with breakfast because I was so keen to start. Now, 30 years older and wiser, I can appreciate much more how lucky I was to have found Intelligent Software and the people who worked there, and how privileged I was to have been so deeply involved at that particular time in computer history: the peak of the home computer boom just before the standardised (IBM) desktop PC took over the world.
 
And I must say everyone at Enterprise Forever is really doing the Enterprise justice. Never in my wildest dreams did I think the Enterprise would still be living 30 years on!

Yes, probably the Enterprise and the TVC is the only home computers which is can run correctly this program:
10 FOR I=1 TO 10 STEP 0.1
20 PRINT I
30 IF I=1.3 THEN STOP
40 NEXT I

I think not a big problem if my computer can be used for calculating

Yes, good example, it's difficult to argue with that!

Thank you very much, I enjoyed reading your posts about memories

About when did you start at the IS?

 I think it was probably December 1982. So 6 months later I started working on the Enterprise, 9 months after that was the pre-launch event of the Your Computer photo.

This is good so far? Can you add some more pieces?

Yes a very good list - don't think I can add much. I can't remember what Nick Vincent did but his initials are on SET STATUS 42 so he must have contributed something in the ROM! He wasn't there from the start like Martin Lea and myself - he came along later in the development. The same goes for CGE who I have just remembered was a Canadian called Charles, but again I cannot put a middle or last name to the initial.

I remember David Legg in the photo working on rotatable 3d view of a chess board (a first in those days). But that was on a PC - I don't know if he had any  input into Cyrus chess on the Enterprise.

Martin Lea may have written some low level parts of the TVC - maybe adapted EXOS and the diskio parts of EXDOS but I can't actually remember - sorry!

I worked on the Enterprise-specific parts of IS-BASIC. Quite a few unplanned enhancements crept in at this stage, such as the multiple program/CHAIN ability

The multiple BASIC programs, with the EDIT n command, and the program list in the INFO: do they come from the FORTH?
(The new CHAIN instruction needed because the BASIC works differently than the FORTH.)

BASIC was mostly done but it soon became clear that it needed to be able to use all the memory, or there wouldn't be much point in buying a 128 instead of a 64.

It's ok. But I think these things (EDIT command, Editor displays number in the Status Line, INFO list program sizes and first line of each program) are ready in the FORTH before the multiple BASIC programs idea come. Because in the FORTH these are natural parts of the language.
When the multiple programs decided, then you started thinking how to do it?
It is very logical if you used "1 EDIT" in the FORTH then put "EDIT 1" to BASIC. And also the other things (status line number, INFO list).