DISTORTED SCROLLER

by Rick O'Neill



Oh blimey, surely not another scroller? But wait! This one's a real

cracker. Not only does it scroll the message of your choice across the

middle of the screen, but it also wobbles it up and down and ripples

rainbow colours across it. All at the same time. (Now I can see you're

interested.) It's been written by none other than Rick "I've Got The

Scrolls Real Bad" O'Neill, the chap who wrote Swiss Scroll back in the

June issue. He's obviously into these things pretty heavily.



The Procedure

The program's an absolute doddle to get working. Just type in the

Basic listing (using stars or something instead of those funny

crossed-out 0s in lines 120 and 130 - they're just my printer being

crap) and SAVE "SCROLLER" LINE 10. Now load up the Hex Loader and use

it to type in the hex listing, specifying 64512 as the start address

and SCROLLER as the filename. Save the resulting code after the Basic,

reload it and watch the amazing demo. Not bad at all, eh?



To use the scroller in your own programs, all you have to do is put

the string you want to scroll into L$ and RANDOMIZE USR 64512 to "hit

it". As well as the usual letters and numbers there are three special

characters you can use ...



CHR$ 124 - This pauses the scroller for half a wave, leaving the message

bouncing up and down. Multiple use will allow you to stop it for as long

as you like.

CHR$ 255 - Repeat from the beginning.

CHR$ 0 - Stop. The scroller can also be halted by pressing Space, except

when it has been paused with CHR$ 124.



Line 105 in the Basic program contains the variable BOLD. Setting this

to 0 turns bold off, and setting it to 1 turns it on. And if you don't

like what happens to the colour, POKE 64680,201, and with 33 to turn

it back on. Address 64686 holds the speed of the colour cycling, which

is initially set to 5.