Re: LZ:83 ASM


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Re: LZ:83 ASM



> > not to mention that teh ti-83 doesn't have memroy-mapped graphics 
> > liek the ti-85,a dn that TI havn't  got round to telling us how to 
> > access the screeen direcly...
> > 
> > (if i had a ti-83 i could probably figure it out, but.....)
>  
> I think they're docs say you can't access it directly, which
> probably means it's not memory mapped.  They probably have a
> chip that controls the screen and you put stuff on the screen
> by telling the chip how to do it.
>
> That's fairly common in Z80 systems of old.  Especially in CP/M
> where the screen was a terminal.  You controled the screen by
> sending escape codes to the terminal.  There was no memory map
> in CP/M in most cases.  The few that did have memory maps, like
> my Kaypro 10, had to pretend they didn't have them when they
> interfaced with CP/M.


KEs, that's what I was thinking (possibley two ports, one for byte 
offset, one for byte to change? , meybe a flags port with a bit to 
toggle??)
it'd be pretty easy to  figure from the _IPoint routine...
(p.s. you you fancy downloading that bit of the rom for me, so I can 
dissasemble it and see how its done?)


Rob Taylor MAIL - mailto:rtaylor@ticalc.org 
           WEB  - http://www.u-net.com/~rtaylor/    


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