HI All,

I am so glad I didn't show any of you my ISR code...it is embarrassing compared to what Darrel has just shared!

I also need to display results as they occur on a 4x20 LCD. There are two different display screens, one that gives a visual representation if a fault has occurred on any particular data line and another that displays actual fault counts for all nine lines. I don't know the timing requirements for LCDOUT statements but I am sure they will add considerably to the 9uS resolution with WORD variables. I could control the LCDOUT routine such that it only updates the LCD screen if a new fault has occurred. Is it possible to do a comparison using this pseudo-code:

Results VAR WORD[9]
OldResults VAR WORD[9]

IF Results <> OldResults THEN
Goto Display Routine ' break to the routine that updates the LCD screen
OldResults = Results ' Reset OldResults
ENDIF

Cheers
Barry
VK2XBP