The PCCOM PCI bus 4 port hybrid adapter is an 32 bits PCI bus board with Plug and Play (PnP) features, it provides four asynchronous serial communication ports (RS232, RS422 or RS485), which link the computer and serial peripheral devices such as terminals, modems, serial printers, plotters, ... etc. The PCCOM PCI bus 4 port hybrid adapter can be used to set different communication mode (RS232, RS422 or RS485) for each port as user requires. User may also plug in ST16C554 or XR16C854 chip on the board as required.

The PCCOM PCI bus 4 port hybrid adapter is particularly suited to facilitate the connection of terminals (VDUs) in multi-user operating systems. The PCCOM board may be installed in any Pentium or hardware compatible systems. The PnP features let hardware configuration for IRQ and I/O address is detected by BIOS automatically, you don’t need set switch and jumper.
 
Since most of the computer has its own COM1 and COM2, the PCCOM PCI bus 4 port hybrid adapter can be configured   from COM3 and COM4.
 
On board ST16C554 chip provides four 16550 functions which contains 16 bytes FIFO buffer for each 16550 ports. There are two kinds of mode can be choose, one is normal speed mode that its baud rate up to 115200, another is quadruple speed mode that its baud rate up to 460K.

On board XR16C854 chip provides four 16850 functions which contains 128 bytes FIFO buffer for each 16850 ports. There are two kinds of mode can be choose, one is dual speed mode that its baud rate up to 230K, another is octal speed mode that its baud rate up to 1M.