Microchip PIC 16F877-20/P microprocessor. This version
is a 40-pin DIP with a 20MHz maximum clock speed.
Comes pre-programmed with Rick Farmer's PICLoader
bootloader software so that you don't need any special hardware or
software in order to download code of your choice to this PIC - programming
can be done over a standard serial connection.
This is the same chip and bootloader used in the Mark III
kit.
If you don't want to use the bootloader, this flash programmable
PIC may be reprogrammed any way you like using a PIC programmer
(not included).