Well, after copious amounts of searching, I came up with this site for a PICkit 2 adapter to program PIC18F's:
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When I plug it in and try to download my hex file, the software just says 'insert device'. Do I need to press the 'reset' button at some point in the process?
Before I go assuming I've blown my chip, can anyone see any obvious problems with the circuit as drawn?
I've checked my wiring 3 times, and doubtless I'll be checking it a few more. I'm specifically trying to get it to work with a PIC18F2455.
Any help/observations/advice is welcome.