Re: A82: Reset of keyboard
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Re: A82: Reset of keyboard
Of course I've tried without the $ff :-) ...and most of the time it works!! When
it doesn't work it seems to do a 'and' with the previous mask.
eg:
ld a,11111011b
out (1),a
in a,(1)
:
:
ld a,11011111b
out (1),a
in a,(1)
The last 'a' is SOMETIMES (I haven't investigate much) equivalent to:
ld a,11011011b
out (1),a
in a,(1)
Quiet weird...
I've found the $ff thecnic in chicken shoot of Harper Madox so I don't think
it's a dream even if the 82-ports.txt doesn't talk about that.
Eric
On Thu, 16 Mar 2000, Jeremy Wazny wrote:
>
> 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
> >
> >
>
>
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