[A83] Re: Direct Input...


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[A83] Re: Direct Input...




I've never used any delays anywhere and it works for me.

Michael Vincent
Detached Solutions - www.detacheds.com
Radical Software - www.radicalsoft.org

----- Original Message -----
From: "Henk Poley" <HPoley@DDS.nl>
To: <assembly-83@lists.ticalc.org>
Sent: Saturday, August 25, 2001 8:09 AM
Subject: [A83] Re: Direct Input...


>
> > Van: Peter-Martijn Kuipers <hyper@hysoft-automation.com>
> >
> > I never used nop's between input and output, and it worked fine.
>
> I meant, should there be a 'delay' between "output and output" to the
> keyboard?
>
> ld a,$FF
> out (1),a
> ld a,group1 ; small "delay"
> out (1),a
> in a,(1)
> ;check keys
>
> or could I just do:
>
> ; H =$FF
> ; C = 1
> ld a,group1
> out (c),h
> out (1),a
> in a,(1)
> ;check keys
>
>
> > > I don't remember ever having to reset the port when reading keys (but
> maybe
> > > I never read more than the arrows using the ports).
>
> As far as I know the output of $FF resets the keyboard. So you can then
> output 'group1' and 'group4' (for example) and read the keys from group1
> and group4 (not that it would be usefull).
>
> So if you wouldn't have reset the keyboard, you could be reading data from
> groups that were enabled during a previous keyboard-read.
>
> Henk Poley <><
>
> > > > With 'Direct Input' you have to reset the keyboard (via outputting
> $FF
> > > > trough port 1), do you have to wait a little for the hardware to
> react? Or
> > > > can you just go on with the next output (to actually switch the the
> > > > groups)?
>
>
>
>





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