A86: Re: Grayscale

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A86: Re: Grayscale


No. An ldir operation of that magnitutde executed every interrupt would hog
the space and make things run unallowably slow. Also, your idea of only
switching certain pixels is insane, because flicker occurs if you don't
change the screens fast enough.

I'm not quite sure what is wrong with the current method of using $FC00 as
primary and $F200 & $F600 as secondary and tertiary planes.

----- Original Message -----
From: Joe <joeknoll@myself.com>
To: <assembly-86@lists.ticalc.org>
Sent: Thursday, January 20, 2000 4:49 PM
Subject: A86: Grayscale


> I just had an idea about grayscaling.  So... most people don't use all
their
> storage memory... so you could have extra screens stored there (instead of
> putting them in the back-end of the dedicated ASM space... well, you could
> do both).  My guess is that (haven't read the code you guys have posted)
> that to switch to another screen you guys' basically switch the port
> location (does that automatically "re-write" the screen?).  So... with
fancy
> work you can use the places in RAM page zero to store more screens.  I
know
> the screen port can't be changed to a value that low; but you could copy
the
> stuff over to page 0.
> okay... overview:  swap out the RAM page with another empty or close to
one
> (someone with a full calc would get an "not enough memory error").  Then
the
> blocks of memory there could be either copied to page 0 and then the port
> could be swtiched.
> Of course I don't know if this has already been totally tried out by
> "everyone" and the z80 just isn't fast enough or the screen isn't or what
> not.  I appoligize in advance if this just sounds lame; but I haven't ever
> followed the grayscale threads and I've never used any in any ASM progs I
> write.
> Another idea:  you could write a side program for the computer that would
> determin exactly what pixels need to be over written and stuff to make the
> gray scale... that would most likely result in larger code... but possibly
> faster grayscale without swapping pages... who knows...
> --Joe
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