output doesn't stay high

[dfort]

I tried this test:

TRISIO = %000000
TimeDelay CON 500

BlinkLoop:
GPIO = %111111
Pause TimeDelay
GPIO= %000000
Pause TimeDelay
Goto BlinkLoop
End




Basically, I am only interested in GPIO.0, GPIO.1 & GPIO.2. On 12f629 & 12f675, sometimes the pins will fire up and start working. Sometimes, I have to flip the switch couple times for it to work. However, it works every time on the 12f683.

This is all on 2 different breadboards with multiple 12f629 and one 12f675 and one 12f683. I don't think all the chips can be defective.

Also, when the 629 & 675 chips are not working, if I touch the chip or one of the I/O pins, the output would start working (driving an LED). I am very puzzled since I have only used the 12f683, but decided to buy cheaper 12f629 models since I don't need all the extra feature.


any more hints? Thanks.