waht ist error : gal ?

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funkheld
Posts: 260
Joined: Mon Feb 26, 2024 11:11 am

Re: waht ist error : gal ?

Post by funkheld »

In text mode there are 128 tiles wide.
You can scroll 1024 x 1 bit with $f938/$f937.
If $f937 has the value 256 then $f938 (Hi-Byte) must be incremented by 1.
$f937 must then be set to 0 again.

thanks
greeting.
hstubbs3
Posts: 72
Joined: Thu Oct 26, 2023 12:14 pm

Re: waht ist error : gal ?

Post by hstubbs3 »

funkheld wrote: Wed Mar 27, 2024 5:41 pm In text mode there are 128 tiles wide.
You can scroll 1024 x 1 bit with $f938/$f937.
If $f937 has the value 256 then $f938 (Hi-Byte) must be incremented by 1.
$f937 must then be set to 0 again.

thanks
greeting.
Yes, this would work for 1024 pixel wide text mode.
$F938 should treat all values with same %4 the same - 0,1,2,3 ... then 0,1,2,3 ... because the documentation says the values wrap at 1024, only the bottom 2 bits of Hi-Byte are used .

In other words - scroll of 0,1024,2048, etc.. all equivalent.
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