Dwayne,

Thanks for the reply. No matter where I place the PAUSE command the problem occurs. It seems to be related to the fact the the PAUSE simply exists somewhere in the code. For example ...

loop:
high PortB.0
low PortB.0
goto loop

works fine. LED lights.

loop:
high PortB.0
low PortB.0
goto loop
PAUSE 500

or,

PAUSE 500
loop:
high PortB.0
low PortB.0
goto loop

does not work.

I have also experimented with the PAUSEUS command and varying the period on both PAUSE commands.

A frquency counter shows the crystal to working as expected at 4MHz and the LED pin at 105KHz. When I add a PAUSE to the code LED pin reads 0 KHz.

Hope this info helps ...

Howard