6502.org

Posted: **Sat Aug 22, 2009 2:24 am**

Quote:

To the "edge detection" poster. You can't do edge detection on the lines, so timing is all you have.

Never tell a hardware hacker something isn't possible.

You absolutely can do edge detection in software.

1$: LDA portA
    AND #bitmask
    BEQ 1$
    ; edge 1 happened here.
2$: LDA portA
    AND #bitmask
    BNE 2$
    ; edge 2 happened here.

I've used this style of synchronization numerous times and with good effect.

Commodore Disk Drive Acceleration Software