Re: A83: Weird LCD stuff

To: assembly-83@lists.ticalc.org
Subject: Re: A83: Weird LCD stuff
From: Olle Hedman <oh@hem.passagen.se>
Date: Sun, 16 Jun 1996 07:34:37 +0100
Delivered-To: assembly-83-outgoing@towerguard.unix.edu.sollentuna.se
In-Reply-To: <63320863.35860c00@aol.com>
Reply-To: assembly-83@lists.ticalc.org



the 1Fh trick is quite easily explained..

the command makes the LCD go into "test-mode" (what that is I don't know)
and it _should_ work with anything between 18h and 1Fh (according to the
LCD Driver data sheet)
The reason why it's not reset is probably just because you remove the
batteries for such a short while, that the memory is still considered safe
and not erased.
but the LCD pops out of "Test Mode" as soon as its power is shut.

the 5Fh is just simply to change the Z-adress to 31.. That is, to change
where in the display RAM the driver should start to read when it shall
output it to the LCD. This function is used in movax's hardware scroll "demo"

anyway.. quite fun to play with the hardware :) 

//Olle

References:

Re: A83: Weird LCD stuff

From: JUSTINJS@aol.com