Type 16780 UARTS are used as the asynchronous communication elements. These include 64-byte transmit/receive FIFO buffers to protect against lost data in multitasking systems while maintaining 100% compatibility with the original IBM serial port (software compatible with Windows COM port drivers).
A crystal oscillator located on the board permits precise baud rate capability up to 115,200. Higher speeds, up to 921.6K, are achieved by installing a jumper on the board.
The addresses of the individual channels and IRQ are stored in non volatile memory on the board and loaded into programmed logic when the board is initially powered.