PROGRAM PITSTOP
Your Sinclair, January 1991

Christmas, eh? What a pile of smelly jobs. Nothing but lots of
washing up and grandparents who keep on telling you how you
need a haircut. It's enough to make you see what JONATHAN DAVIES
has in store for this month's Program Pitstop, isn't it?



So it's nearly Christmas again. Who'd have thought it, eh? And, as
usual, I'll be blowed if I can find any presents to buy for anyone.
Last time round the best I could come up with was a selection of the
usual handkerchiefs, chocolates and National Trust calendars, which
was received with courteous disdain (just like the year before). So
this time I'd like to do a bit better. I've set aside a sizeable
dollop of my newly-acquired Student Loan and I'd like your ideas on
how to spend it. Yes, 'reader feedback' is what I'm after here, so jot
down those gift ideas on a coupon of your making and send them to me.
Oh, and scribble down the gift of your choice while you're at it. The
sender of the best set of suggestions will receive a present, you see,
and I'd like to know what sort of things to buy. It'd better be cheap
though. (A game would be ideal.)

While you're thinking about that here are two programs to try out.
There's Life, which wins JW Joyce a rather fabulous 50 and let's you
experiment with, erm, 'life'. But before that there's a speedy
circle-drawing routine by Darrell Smith to replace your Speccy's
creeky built-in one.

What fun. (You might well ask. Ed)


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CIRCLES
by Darrell Smith

If you added up all the time you've spent waiting for your Spectrum to
draw circles you'd probably have enough for a long weekend in Margate
(although watching the circles would be eminently more satisfying).
Darrell Smith has set out to address this problem with his alternative
circle-drawing routine which does the job a whole lot faster. Circles
now just sort of 'appear', which means you can use them for purposes
you'd never previously have bothered with. (Actually I think a similar
program appeared in Pitstop ages ago, but I couldn't find it and
neither, presumably, will you.)

To get it going, type in the Basic (which is mostly a demo and could
therefore be discarded) and save it by doing SAVE "Circles" LINE 1035.
Then, using the Hex Loader, type in the Hex and save it as "CIRCLE
M/C". Reload the whole thing run it and watch the demo.

To draw you own circles...
POKE 56001, x co-ordinate
POKE 56008, y co-ordinate
POKE 56015, radius
and then RANDOMIZE USR 56000.


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LIFE
by J.W. Joyce

In case you were wondering, this program doesn't actually bring your
Spectrum to life as such. What it does do, though, is a very passable
impression of the ancient game of Life which has been around on
computers more or less since they were first invented. In fact, if you
bought an original rubber- keyed Spectrum you may well have got a
version of this thrown in. But JW's version is miles better than
anything you'll have seen before.

So just what is the meaning of Life? Well, apart from an excuse for
lots of crap 'life' gags, it's a sort of game thing that was invented
in 1970 by John Conway of Cambridge University (it says here). The
screen is divided up into lots of cells which you have to pretend are
alive. Although their initial layout is decided by you, the computer
then takes over and makes them grow or die out according to the
following rules - every live cell that has either two or three
neighbours will survive 'til the next generation, all other cells will
die, and a new cell will be born in any space which has precisely
three live neighbours. As time passes your 'colony' will develop into
lots of spooky patterns, eventually either dying out or becoming stable.

Right, time to type it in. The first thing to do is to type in the Hex
using the Hex Loader and save it to tape. You'll notice a couple of
Basic programs as well, but these are non- essential and can be
ignored for now.

This version of the game is different from others because it treats
every pixel on the screen as a cell, rather than having huge chunky
cells. This means you're able to create much more complicated patterns
than usual, and it also opens up a wide range of possibilities
regarding the initial layout of the cells. The only thing is, there
isn't actually a 'screen designer' routine as such, like you usually
get with Life games. But you don't actually need one. Because the
program uses the hi-res screen to generate its patterns; all you've
got to do is draw some things on the screen (using the PLOT, DRAW and
CIRCLE commands, for example) and run the program on them. You could
even bring a screen full of text to life, like a program listing. And
that's where the two Basic programs come in. They simply draw patterns
on the screen and then animate them using the Life routine.

To get it going then load in the Hex that you saved previously with
LOAD "" CODE, draw some things on the screen and then repeatedly
RANDOMIZE USR 42249 to update it. The Basic demos should clarify
things if you're not too sure.

