This project tests the construction of a PIC µcontroller with an RS232 interface. The basic requirement is that a HyperTerminal session on a PC should be able to send data to and receive correspnding data from the PIC.
The intention is to use the USART interrupts to buffer the send and receive. There are 2 subroutines to access the simulated input and output LIFO buffers. Indirect addressing is used. The buffer sizes are 4 bytes each! The interrupt handler also accesses the buffers either reading or writing.