Re: A89: Re: help?

To: <assembly-89@lists.ticalc.org>
Subject: Re: A89: Re: help?
From: "Niklas Brunlid" <e96nbr@efd.lth.se>
Date: Thu, 6 Jan 2000 01:32:19 +0100
References: <53.53f58f05.25a53812@aol.com>
Reply-To: assembly-89@lists.ticalc.org


> > Are you running this on a HW2 calc? If so, try replacing this line with:
> >   move.b (a1)+,(a0)
> >   move.b (a0),(a0)+
> Why is this necessary?

Because of the way the LCD hardware is wired on HW2. What you see on the screen
is actually not what's in the LCD memory, but in a buffer. Whenever you write to
the LCD memory whatever was there before gets bumped to the buffer, which the
LCD displays. It works like a double-buffer, actually. So to get the GFX
displayed directly when you don't constantly update the screen you have to
"write it twice", or copy it to itself.

 / Niklas Brunlid
Check out Prosit for the TI-89 / TI-92+ at http://prosit.ticalc.org
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References:

Re: A89: Re: help?

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