FULLSCREEN SCROLLER

This is an explanation of the routine DEMO520.S which is in the 
ASSEMBLER folder.You can use that source to produce a nice 
demoeffect (it is used in many demos).The effect is a large Atari 
sign scrolling upwards (or was it downwards...I don't remember!).
There is no music,only that Atari sign.The blocks of the sign is 
made in the program so there is nothing the source has to put 
into the file.
The documentation of the file is good,but sorry...it's in 
Swedish!So all of you who can't read Swedish,you will have to 
make it without th explanations.I'll try to tell you something 
about the routine.
First of all,go to the label copy_blk by using find in the menu.
When you are there,go to the line

          moveq     #11,d1

The number (#) 11 shows how many lines there are with blocks.
You can change it to,for example,5,to get only the half of the 
screen scrolling.But then you'll have to change a few more 
things.They will come down here...
Next step is...go to the label blk_loop.There you will find a 
line where it stands:

          moveq     #19,d0

That #19 shows how many blocks there are per line.Write #9 
instead of #19 and see what happens (I don't know...maybe it 
won't work!).
The next step is:go to the label blk_loop2.There is a line where 
it stands:

          moveq     #15,d2

That #15 means how many lines the block is.Try to change that too 
and see what happens.
Now,if you don't own a 520 ST,what do you do then??Well,go to the 
label called copy_screens.There is a line where it stands:

          lea  $30000,a1

Now change that $30000 (only if you got 1 MEG or more!) to 
$80000.The go to the label currpicadd & currpicadd2 and change 
the $30000's there to $80000 and woops,you've got a MEG version!
Then go to the label pal and the label block and change the 
colors to whatever you want.
Then the last things:go to the label atari and there you can 
change the atari sign to anything you want,maybe a TPS sign 
instead!At last go to the label text and write a line with some 
nice text.Now your'e finished!
 
Thanx to An Cool for writing the source...

Explanation of changing the source by Sorcerer of The Digital Dictators!