Parallel Interface; Serial Interface - NEC VERSA 6220 Service Manual

PARALLEL INTERFACE

The system' s parallel interface integrates National Semiconductor's PC87338 chip with a
25-pin D-subconnector. The port is located on the system's rear panel.
The modes of operation available for a PC87338 chip are:
T
compatibility mode
T
nibble mode
T
byte mode
T
Extended Capabilities Port (ECP)
T
Enhanced Parallel Port (EPP).
The user selects between four parallel interface modes using Auto Setup. These include
unidirectional, bidirectional, extended or enhanced. Unidirectional mode sends data output
from the standard ISA port only. Bidirectional mode sends data using the standard ISA port
or PS/2 technology. Enhanced mode enables high speed data transmission to occur using
either the unidirectional or bidirectional modes.
The default parallel port address is 378h and the interrupt level is IRQ07. Pin locations for
the parallel interface are listed in Appendix A.

SERIAL INTERFACE

The RS-232C serial port is a 9-pin connector on the system's rear panel. The serial port
consists of a 16550A and 16450 compatible serial port controller with a programmable
baud rate up to 115,200 bps. The serial port connects an RS-232C device or an external
modem. The default serial port address is 3F8h and the interrupt level is IRQ04.
Technical Information 1-17