Hi all. I've been looking at some of Andrew Warren's code at
http://reocities.com/SiliconValley/2499/code.html - In particular, the
BCD clock. I'd like to add a small stopwatch function to allow timing
in a current project, and this seemed pretty easy. Just call the
routine at 1Hz and have numbers ready to be put out to display.

Unfortunately for me, I'm not as good at fancy code as Andrew and
Scott Dattalo, who both worked on this routine. So I'm a little
confused.

I think I get the basic gist of what's going on, but I don't
understand the use of constants in a couple of the commands,
specifically:

     MOVLW   0100H - 060H
and
     RETLW   0100H - 024H

I'm not really sure why constants in an equation are used here rather
than just the result of the equation.

Also, am I correct in assuming SKPNC is "skip if no carry" and SKPDC
is "skip if yes carry"? I've never really been able to find out
exactly where those special instuctions come from.

I think the lack of comments in that code is hampering me.

Thanks!

Josh
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