A85: Re: Re: Scrolling

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A85: Re: Re: Scrolling

 
-----Original Message-----
From: Dines Christy Justesen <c958362@student.dtu.dk>
To: assembly-85 <assembly-85@lists.ticalc.org>
Date: Friday, August 07, 1998 9:41 AM
Subject: A85: Re: Scrolling

>
>Wouldn't the following work:
>
>SLeft:
>  LD HL,$FC00+1 ; Scroll left
>  LD DE,$FC00
>  lD BC,1023
>  LDIR
>  RET
>
>SRight:
>  LD HL,$FC00+1022 ; Scroll right
>  LD DE,$FC00+1023
>  lD BC,1023
>  LDDR
>  RET
>
>SUp:
>  LD HL,$FC00+16
>  LD DE,$FC00
>  LD BC,1024-16
>  LDIR
>  RET
>
>SDown:
>  LD HL,$FC00+1023-16
>  LD DE,$FC00+1023
>  LD BC,1024-16
>  LDDR
>  RET
>
>Dines
>-----Original Message-----
 
No.  this would do a lot of wierd stuff.
first of all, it moves 8 pixels over left and right
  Next of all, it dsnt keep the screen intact
the image that is
 
if  the screen looks like this: (greatly simplified)
 
 
abcdefg
hijklmn
opqrstu
 
after your move right routine, it would look like this:
 
aabcdef
ghijklm
nopqrst
 
see what i mean?
 
it should be:
 
aabcdef
hhijklm
oopqrst
 
In theses examples i didnt protray the 8pixel movments instead of one.  i greatly simplified.
 
Jonathan Kaus