Re: A82: Reset of keyboard

To: assembly-82@lists.ticalc.org
Subject: Re: A82: Reset of keyboard
From: Jeremy Wazny <j.wazny@ugrad.unimelb.edu.au>
Date: Thu, 16 Mar 2000 22:53:43 +1100 (AEDT)
In-Reply-To: <Pine.OSF.4.02.10003161134240.31057-100000@vega.utc.fr>
Reply-To: assembly-82@lists.ticalc.org

Hello,

I don't remember ever having to do such a thing, even when writing a
number of masks in quick succession. Also, Dines' excellent "82-ports.txt"
makes no mention of resetting with $ff. Have you tried it without doing
this?

-Jeremy

On Thu, 16 Mar 2000, Eric Piel wrote:

> 
> Hi
> Writing additional code in the Key handler of BMMP I remind the fact that it is
> necesary to reset the keyboard port by sending ff before every scanning.
> for instance:
>         ld	a,0ffh				; reset keyport
>         out	(P_KEYBOARD),a			; necessary code?
> 	ld	a,%11101111
> 	out	(P_KEYBOARD),a			; Mask out 0/4
> 	in	a,(P_KEYBOARD)
> 
> I'd like to know if it has to be send every time or not and why.
> BTW has someone done more advance investigations about this subject?
> 
> Eric
> 
>

Follow-Ups:

Re: A82: Reset of keyboard

From: Eric Piel <pieleric@etu.utc.fr>

References:

A82: Reset of keyboard

From: Eric Piel <pieleric@etu.utc.fr>