Re: A86: APD

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

Re: A86: APD

After it decrements the contents of hl (the subtimer), it increments hl (now points to timer) and decrements it's contents. It then sets the flags and turns the calc off with the regular call.  Which means that you were right and that the best way (the correct way) to shut off the calc with the APD is by doing:

        res 3,(iy+8)
        set 4,(iy+8)
        call $4101

I think this would be the right code for an interupt:

        push de
        push bc
        push hl
 
        in a,(3)
        bit 3,a
        jr nz,exit
        res 3,(iy+8)
        set 4,(iy+8)
        call $4101
exit:
        pop hl
        pop bc
        pop de
        ret

Kirk Meyer wrote:

 you're right = $0181 is it.  look at the bits there.     Kirk    _@ibm.net
Follow-Ups: References: