Hi Gopher,

I noticed 9 holes on the front view. Alot of products in the alarm industry have either pads or holes for ICSP programming. It's possible that these holes might be for a tester or programmer. Try metering them to see if they connect to the ICSP pins on the PIC. Like you said, you've got alot of these boards. The RS232 chip could be for sending and receiving data and/or could be for a bootloader as was mentioned earlier.

HTH,

BobK