Hi folks,
        I am new to the list and also new to the Pic processors, however to get
up to speed with the processor I purchased the Pic demo-2 PCB and whilst running the demo software supplied for the keyboard - LCD routine found that keyboard interrupts were not working... now I thought that as I was new to the Pic processor, the Pic demo board, MP-Labc, and the ice, that the problem was mine. However after hours of checking software etc. I found that the two resistor packs installed on the Picdem-2 board installed between the keyboard input and port b ( resistor packs RN4 & RN5 (1k value)) were limiting the current to well, and acting as a voltage divider (with the internal pull-up resistors on port b), the end result is that the keyboard cannot take port b bits 4 to 7 down to ground, and therefore no interrupt was seen by the processor. I haven't tested this on silicon yet, maybe its the ice, or maybe Microchip have installed the incorrect value of resistance for this circuit.

Can anybody give me an idea as to the approximate value of resistance when enabling the internal pull up on the Pic devices, as this may prove useful knowledge for future development on my side.

I hope that this information may save other's testing development on the Picdem-2 time.

Arthur.