Re: A86: Problem reading ports
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Re: A86: Problem reading ports
In a message dated 1/19/00 6:52:50 PM Mountain Standard Time,
neophile_17@hotmail.com writes:
> This is a read key loop except the loop is broken as if exit was pressed
> when it wasn't. I think this is because the mask is %10111111
and
> bit six is already missing but I don't know how to fix it if it is.
>
> ld a,$BF
> out (1),a
> bit 5,a
> jr z,Second
> bit 6,a
> jp z,Exit ;heres where it breaks
>
> Any help would be appreciated. Thanx.
> ~neophile_17
Someone probably answered this (too many of those off-topic posts...), but
you need to do a < in a,(1)> to get what keys are currently down for the
particular key group you want. Also, might wanna put a few < nop>s between
the 'out' and the 'in', as that's what the TI-OS does:
ld a,$BF
out (1),a
nop
nop
nop
nop
in a,(1)
bit 5,a
jr z,Second
bit 6,a
jp z,Exit
JayEll