CHAPTER 1
INTRODUCTION

The PCCOM 4 port RS422 adapter provides four asynchronous serial communication ports, which link the computer and serial peripheral devices such as terminals, modems, serial printers, plotters, ... etc. A programmable baud rate generator allows operation from 50 baud to 56K baud and up to 3000 ft transmission distance.

The PCCOM 4 port RS422 adapter is particularly suited to facilitate the connection of terminals (VDUs) in multi-user operating systems. The PCCOM board may be installed in any IBM PC/AT, PC/386, PC/486, Pentium or hardware compatible systems. To accommodate a variety of operating systems, three jumper blocks and one switch permit maximum flexibility of configuration. You may select which interrupt (IRQ2 - IRQ7), I/O address, and interrupt vector you desire.

The PCCOM 4 port RS422 adapter can be configured to either compatible mode or enhanced mode. When configured to compatible mode, it takes the place of the standard serial ports (COM1:,COM2:). When configured to enhanced mode, the four ports coexist with standard serial ports.

The PCCOM 4 port board can be used to plug in 8250, 16450, 16550, or 16650 chips, and the PCCOM98 device driver can detect it automatically. There are two kinds of board can be choose, one is normal speed card that its baud rate up to 460K.