I've put up a schematic Inchworm; on my site of my take on the many fine designs of Microchip ICD2 emulators on the web. It's based mostly on the excellent version by Lothar Stolz.
I've used the MAX232 as a voltage tripler to get the ~12.5v needed for VPP and added handy busy & power LEDs.
You will need to program the bootloader "bl010101.hex" file located in the ICD2 directory onto a 16F876 (or 877) C:\\Program Files\\Microchip\\MPLAB IDE\\ICD2\\BL010101.HEX
A simple programmer like the one with PonyProg
enjoy