SQUELCH!

by Robin Holman



[The BASIC listing for this was chopped off in the magazine from the middle]

[of line 70. Making some deductions from comments in the description below ]

[I restored what seem to be likely versions of the missing lines to give a ]

[working demo program.                                                 JimG]



If you're one of those people who write a three line letter all the

way from Australia just to tell me that I made a spelling mistake on

page 92 of the August issue, then you'll probably complain that this

routine isn't technically a screen effect. Well it is, so shuddup.

This program squelches a screen, attributes and all, in such a way

that a cute cuddly miniature of it appears. Great eh? And it's easy to

use too!



Method

Use the Hex Loader to load the hex listing into 50000 and save it with

SAVE "squelch1" CODE 50000,218. Then type in the little Basic

controller and save it with SAVE "squelch2" LINE 90. Then RUN the

program.





SQUELCHING

Firstly the program'll ask you for Y co-ord (0-12) and then an X

co-ord (0-16), these are the co-ordinates where the compressed screen

will appear. Then you'll have to load in a screen, so have a tape on

hand; and after you've loaded in a screen - squelch! The compressed

version then appears on screen. This can be repeated again and again

simply by pressing L until the screen is full of squelched screens.

Once you've a competent number of compressed graphics bursting out all

over the TV you can save the whole lot by pressing E. Simple innit?



INDEPENDENT COMPRESSION

Should you wish to utilise the code outside normal working hours (and

Basic program) here are some details you should know.



* To compress the current screen use:

  POKE 50003, X co-ord (0-16)

  POKE 50001, y co-ord (0-12)

  RANDOMIZE USR 50000

* The compressed screens reside at 32768 to 39680

* The program uses addresses60000 to 60012 as temporary storage



A great screen clearing effect can be created if you repeatedly call

the squelch routine until the screen disappears.



SQUASH!

Well that just about wraps it up as they say. But Robin does say that

he doesn't mind people using the routine in their own programs

although he doesn't want it copied out to jam into a fanzine. Got that.