12F683 internal pull up

[hvacrtech]

If you have internal pull-ups ON, and you're testing the input pin for logic 1, the only
way your LED shoud NOT blink would be when GPIO.5 is pulled to ground.

That way it been erratic behavior and You are right about that the led should not blink when GPIO.5 is opened. that way when I opened the path from ground, the led still blinks. After I added INTCON=0 to it, it behaves much better and dont blink when opened. When I closed the GPIO.5 to ground, the led did blink.

I dont know why but added INTCON=0, system stablizes. Like other PIC I know dont have issues with out this configuration. Maybe it a requirement?

[Bruce]

Clearing INTCON should not be necessary unless you had previously placed some value
in it you need to clear. At power on INTCON by default is already clear.

If it wasn't you could really have some odd behaviour with unexpected interrupts firing.