Hi Ken,

>I have a project that I am about to start that requires some accurate timing
>loops of odd lenghts. There is a basic program on the microchip BBS that will
>generate the code for any lenght loop you need, but I also need to check for
>some buttons being pressed while the loop is being exacuted. The program AW.BAS
>does not do anything in the main loop and I can't see how to modify it to
>include extra instruction.

You'll need to add instructions to the inner loop like this:
loop:
        decfsz   r1
        goto    loop

becomes (e.g. to test 1 bit with a button on)

loop:
        btfsc   ff, bb          ; Replace ff & bb with bits to test
        goto    buttonpress
        decfsz  r1
        goto    loop

and then redo the constants at the beginning of the program to reflect the
longer inner loop.  We've got a 5-cycle inner loop here, so the calculations
become:

        tloop = 5               : REM Pulled out to a variable to ease mods

        x = delay - (13 + tloop): REM Minimum time through delay routine

        d = int(x/(((tloop*256 + 2)*256 + 2)*256 + 2))
        x = x - d*(((tloop*256 + 2)*256 + 2)*256 + 2)
        c = int(x/((tloop*256 + 2)*256 + 2))
        x = x - c*((tloop*256 + 2)*256 + 2)
        b = int(x/(tloop*256 + 2))
        x = x - b*(tloop*256 + 2)
        a = int(x/tloop)

        x = tloop*a + (tloop*256+2)*b + ((tloop*256+2)*256+2)*c +
(((tloop*256+2)*256+2)*256+2)*d + 8

        a=a+1:b=b+1:c=c+1:d=d+1

The principle holds for longer inner loops (if, e.g. you wanted to test more
than one bit.)

Caveat emptor!  I've not tested this, but it's a start at least.

Dave