Re: A89: ROM 1.05 and grayscales
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Re: A89: ROM 1.05 and grayscales
> >Hi,
> >
> >You maybe know that the grayscales no longer work on the new 1.05 ROM
> >I think I've found out why : you know the greyscale handler relies on auto
> >interrupt one which runs at 300 Hz. This handler switches 2 virtual screens
> >in B&W, giving the impression of 4 gray levels, and then RUNS THE OLD AUTO
> >INT 1 HANDLER, ie the TIOS one in most cases.
> >
> >The problem is that it seems that the auto int 1 handler from the new 1.05
> >ROM is too slow to allow a sufficient refresh rate -> there is no
> >impression of 4 grayscales..
> >
> >So, what ? The solution'd be that the grayscale handler no longer calls the
> >old auto int 1 handler, but this will prevent the program to use functions
> >such as userlib::idle_loop, as well as the APD features when it is running
> >in grayscales.
> >
> >What should I do ?
> >Xavier VASSOR
> >E-mail:xvassor@mail.dotcom.fr
> >Homepage: http://start.at/doors
> >ICQ:10241721
>
> Well, as I read on the homepage to ACZ, auto int 3 isn't used by the TI-89.
> But is it unused, or is there just an 'rte' at the address which gets called
> with the vector to auto int 3? In this case just use auto int 3 for
> grayscales!
Auto-int 3 isn't called on a regular interval like 1 or 5.
> Anyway, in programs using grayscales, mainly games, the tios routines are
> too slow anyway!
Actually many of them are suprisingly good. It's just that they must be able to
handle all possible cases and can't be optimized for one single task.
/ Niklas Brunlid
Check out Prosit for the TI-89 / TI-92 Plus at http://c625.sparta.lu.se
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