Programming 12F683 in QBASIC

[Heckler]

That GP3 has tripped me up more than a few times as I was just learning. That is true, it can only act as an input (or the MCLR, depending on your configuration fuses)

In fact on all the PIC's that I have worked with so far... What ever pin is the MCLR pin can ONLY act as Input or MCLR.
All the other 5 pins can act as either input or output depending on the TRISA register.

Be sure and get (download) the datasheet for any PIC that you choose to work with.
It is essential to refer to as you are setting up and defining the pin functions and other features (timers, A/D, PWM, etc).

The configuration (CONFIG) register is the one that defines the function of that GP3 pin, (and other things like WDT, Brown Out Reset, etc). This register can ONLY be defined at the time you burn the program into the PIC. It can NOT be changed on the fly by your program as it runs. So you must choose how you want the bits in the CONFIG register set and leave them that way unitl you re-program the PIC.

good luck