PROGRAM PITSTOP
Your Sinclair, July 1989

Here's a possum who knows how to pose! Introducing new man Jonathan
Davies - your newly-installed Pitstop pop picker.

After McCandless's recent and unfortunate error in the spelling of my
name we probably won't be seeing much of him around here for a while.
And he hadn't even joined BUPA. Tragic. Anyway, it's just you and me
now. And that undoubtedly awful photo. Having strategically placed
your thumb over it, let's take a peek at what's available in this
month's Pitstop.

For starters, a couple of specialist programs, one for Multifacers and
one for 128Kers. Anthony Purvis's Super Text Search is distinctly
long, but well worth the effort, and Shimon Young does unnerving
things with your screen memory. These are closely followed by a
bizarre but eye-catching program from Dan Nielson.

Incidentally, has anyone out there done anything interesting with
fractals on the Speccy? You have? Send it in, and if I like it you
could become instantly famous. Oooh, what a feeling of power!

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SUPER TEXT SEARCH
by Anthony Purvis

[SEARCH is the original code, using IN,A(9F)/IN,A(1F) to page the    ]
[Multiface RAM in/out. The emulators I tried wouldn't work with this,]
[so SEARCH2 uses IN,A(BF)/IN,A(3F), which works.                 JimG]

If you're one of the privileged few with a Multiface, who's a bit
weary of backing up your software collection with it, this succulent
wodge of Hex from Anthony 'Purv' Purvis could be for you. Multiprints
are also suitable, but not Multiface 3s, so ner.

What we have here is a search-and-replace utility along the same sort
of lines as the ones found in any word processors worth their salt.
The difference is that this loads into your Multiface's on-board RAM
and sits there until you press your little red button, whereupon a
menu pops up allowing you to hunt through the game you're in the
middle of, letting you change all occurrences of the word 'aliens' to
'parsnips'. All in under a second. The potential is quite frightening.

Fiddly
It's a bit fiddly to get going, so concentrate. First of all, type in
the Basic Loader below and save it onto tape with SAVE "search" LINE
10. If you have a Multiface 128 which is set up for use with the
Disciple interface you should add line:
 35 POKE 40001,191: POKE 40051,63

Next, funtime. Using the Hex Loader, bash in the colossal hex listing
(without putting spaces between bytes - they're to make it easier to
read) and type "STOP" (Symbol Shift A) to save the code after the
Basic bit.

Finally, it's necessary to make a copy of the character set, as the
Multiface overlays this when it's activated. You can either use one
you prepared earlier, or type in the following program and save the
code it generates after the first two sections.

Doddle
From now on it's peasy. Rewind the tape, make sure the Multiface is
enabled, but not activated, and LOAD "" in the traditional manner. The
program will install itself and then disappear. Now choose a decent
game and load it up as normal.

Whenever you feel the urge, press the knob and prepare to be bowled
over. In place of the boring old Multiface menu will be a new one with
three options:

Strings is the one to use when you want to enter or replace a string.
This shouldn't be any longer than the original or it will be brutally
truncated.

Go, well, goes! Within the twitch of an earlobe the program will do
its stuff and report back with a self-explanatory message, leaving you
wibbling in its wake.

Ret returns to the game so you can see the results of your dastardly
handiwork. Sabotage Finally, in case you tire of mutilating other
people's codes (unlikely) or want to make a copy of the "revised"
program, hold down Break and hit the button. Normality will be
restored.

Coming soon, from the same author, Setsearch! You lucky people!

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WIPER
by Shimon Young

Nothing to do with windscreens or Andrex, Wiper by Shimon Young
(Shurely shome mishtake! Ed) reveals one of the 128K Speccy's
innermost secrets. The thing actually has two chunks of screen memory,
which can be swopped between at will. This means you can draw a
picture on one screen while innocently displaying the other and, when
it's finished, page in your masterpiece instantly - to the
bewilderment of onlookers. Wiper lets you do all this and (of course)
more ...

Pic 'n' Mix
Type in the short Basic loader which doubles as a demo of the
extraordinary power that is about to be unleashed. Save it onto tape
with SAVE "Wiper" LINE 1, and then hammer in the mercifully short hex
dump using the Hexloader (from Super Text Search). Save that after the
Basic part.

Now you'll need to find a couple of old saved screens from somewhere.
Having done so, reload the program which will then wait while you load
in the piccies. Finally, sit back and ogle as the two screens are
wiped between utterly smoothly and without any hint of colour clash.
Astounding. "Throw away your Quantel," as Shimes puts it.

Et Voila!
In order to make use of the routine in your own programs you'll need
the following info, all of which is alluded to in the demo.

To load a picture into the second screen area:
POKE 23388,23: LOAD "" CODE 49152.
You won't be able to see it, but it's there all right. Then to unveil
it, RANDOMIZE USR one of the following:
48946 - Wipe up
48966 - Wipe down
48983 - Boing!

You'll notice that while the second screen is paged in, all PRINTs,
PLOTs and the rest are still directed to the normal display, so you
can create your masterpiece in total secrecy and then wipe back to
reveal the results. Bear in mind, though, that every time you return
to the Basic editor the standard screen will reappear.

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TOP SCREEN EFFECT
by Dan B. Nielsen

While this snappily-titled program may appear on the surface to be
completely pointless, and probably underneath as well, I assure you
that you'll be messing about with it for hours. There's also the bonus
that it comes from Dan Nielsen who lives in Denmark, land of bacon,
Lego and a rather tasty blue cheese.

What does it do? It's hard to explain, really. A kind of scrolly
effect would be a good estimate, I think, but the easiest way to find
out is to type it in and see. There's a terribly impressive demo
program that should clarify everything.

Enjoy
Simplicity itself. Knock in the Basic demo program and save it with
SAVE "thingy" LINE 10. Then, with the aid of the Hex Loader (from
Super Text Search), enter the hex listing, typing "SCREEF.cd" as the
filename. Shouldn't take too long. Then save it after the demo by
pressing STOP.

All that remains to do is to reset, reload, relax and enjoy.

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Fin
By now you'll probably be wondering how you too can become part of the
phenomenon that is Program Pitstop. Easy as Pi. Just send a copy of
your latest creation, on tape, to me at the address below, and before
long you could be the proud possessor of a YS badge and a
much-inflated ego. Today Pitstop, tomorrow the world, and all the rest
of it. So send your programs to Jonathan Davies, Program Pitstop, Your
Sinclair, 14 Rathbone Place, London W1P 1DE. I'll be waiting for your
call.
