[A83] Re: Direct Input...


[Prev][Next][Index][Thread]

[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)?





Follow-Ups: