RE: A83: an idea for greyscale


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RE: A83: an idea for greyscale




At 02:49 2001-02-09, you wrote:
>yea... but maybe we could change fastcopy so it only copies half the screen
>or something.  (As you can see, I'm very interested in greyscale on the
>83+)  That would probably be best for some simple greyscale game.  My
>original idea could be used in some sort of a picture viewer.  The idea is
>that it only displays the totally black and totally white bytes once, and
>displays the grey once twice to make them grey.  I dunno.  Just a couple of
>ideas from somebody that isn't good enough at asm (yet) to implement them
>;-)

There is no problem to write half the screen. There is commands for 
changeing what xpos and/or ypos to start to write on. The fastest 
screencopyroutines work with columns, since you then have to only write 12 
times to the port for changeing column, instead of 64 times to change row.
counter select command modifies this behavior.
Z adress set can be used for hardware scrolling. X and Y adress set is.. 
yes, well guess :)
test mode select has been discussed a lot in the "TI COLOR"-thread...
Please download t6a04.pdf from 
ftp://d188.ryd.student.liu.se/calculator/ti83/tech/ and check page 13. 
There you have all the commands that you can send to the lcd-driver. Thoose 
with D/I = 0 is the ones you write(read) to lcd command port, and thoose 
two at the bottom with D/I = 1 is the ones you write(read) to lcd data 
port. (what is it? 10 and 11? 10 and 9? don't remember, was more then 2 
years ago I had a ti83)

///Olle




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