Hi Gang, Long time no post.

I've got a 10F222 that's been programmed successfully (custom ZIF connection, verifies and reads back fine), with simple test code to blink an LED on GPIO.0 - but for the life of me I cannot get it to work, whether the LED is connected to the output as active-high or active-low.

Is there something I've overlooked here? Suggestions? I've been stymied before with something as simple as turning a comparator off, but this is such a simple microcontroller and has very little housekeeping.

Code:
'   set parameters
'
ADCON0=0 'all digital I/O
TRISIO=%0000 'all outputs (GPIO.3 is input only so it's ignored)
Define OSC 8
'*************************************
'     variables and constants
'
tempvar var byte
'***********************************
'	Other housekeeping
peekcode $1FF, tempvar 'OSCCAL calibration value
POKE $05, tempvar	  'OSCCAL register location
'**************************************************************
'     begin program

GPIO.0=0

loophere:
GPIO.0=1
pause 500
GPIO.0=0
pause 500

goto loophere

end