I finally got around to putting my 'new' PIC onto my new breadboard, the cool 16F690. It is very easy to rig up, only 3 external components for a minimal set-up. I wasn't sure if the Willem PCB3 programmer would work with it because the programmer is getting a bit long in the tooth, but by selecting a similar chip in the inventory it worked and I had a wonderful flashing LED. The program I wrote actually does an awful lot more than flash an LED, but that's always a good way to see something happening. Just as well because I then hooked up a 4x20 character HD44780 display and didn't quite get what I was expecting. The display is working correctly, but the code is sending some weird characters and I suspect a timing issue, so I'll look into that.
I'll sort an RS232 interface tomorrow and then we are well on the way to some tasty vehicle diagnostics.