RE: A82: Greyscale Mentioned?

To: <assembly-82@lists.ticalc.org>
Subject: RE: A82: Greyscale Mentioned?
From: "CrASH_Man" <crashman@crashware.lfx.org>
Date: Tue, 27 Jul 1999 23:08:56 -0700
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Speaking of greyscale, I thought of a strange way to make a greyscale
picture...  Use the top half of the LCD for the light grays and the bottom
half for the dark grays, and then use an ISR to switch the hardware scroll
offset to halfway (though you get only half of a grayscale pic)  If anyone
would be willing to try it, it might look way cool :)

I heard of a new greyscale engine that works quite well for the 82, though i
don't know where to get it
I'll find it and check it out.

Ah, and about emulation on VTI...  It seems that the interrupts do not go
off at the same rate on the computer as the calculator.  Also, on the
calculator, the interrupt speed seems to be 100Hz, instead of 200Hz which
the TI-85 is believed to be.  I made a program the other day to time how
fast the interrupts are going off, and the results are as follows (probably
to the nearest 20 Hz):

out ($04), $16 (normal interrupt speed)  100Hz
out ($04), $14 (faster speed)          140Hz
out ($04), $12 (even faster speed)      220Hz
out ($04), $10 (fastest speed)         480Hz

Maybe someone else can come up with more accurate measurements :P

-crashman

> Ive read that ADAMMAN is using Greyscale for Defiance, and Jeremy
> is using it
> for AgentX... Would y'all mind posting any source code you have
> on that?  I
> would assume the greyscale interrupt technique is very similar to
> what the 83
> can do, and I have been experimenting alot with greyscale for the
> past week,
> and a month ago before this, yet I cant get it to be of any good
> quality... I
> got perfect greyscale on VTI, but that means nothing since it
> doesnt Emulate
> the hardware in any similar way... Please inform me about any new
> techniques
> there are... :)
>
> Jason_K

References:

A82: Greyscale Mentioned?

From: Jkhum98@aol.com