I remember looking at 18F datasheets and felt like I was in a different world. Since the 876 was at hand that seemed the PIC to use for now. The I2C and SPI connections are set on the correct pins and ports, so I can move to those functions later. For now, I just needed to take baby steps in learning how to run the SPI and I2C without adding learning the hardware too. When I (if I) move to those hardware functions I should have a better idea of what they expect and how to use them.