1-16 Technical Information
SERIAL INTERFACE
The system has two standard serial ports (COM1 and COM2). The serial ports support the
standard RS-232C interface (16550 compatible). I/O addresses and interrupt levels for the
two channels are given in Table Section 1-15. The interrupt is selectable via Setup to either
IRQ3 or IRQ4. Software selectable base addresses are 3F8h, 2F8h, 3E8h, and 2E8h. Serial
interface signals are output through the system board's 9-pin, D-subconnector. The con-
nectors are located at the rear of the system unit. Pin locations for the serial interface con-
nector are shown in Appendix A.
NOTE:
Interrupts used for the built-in serial
ports are not available for ISA parallel ports.
Table Section 1-15 Serial Port Addressing and Interrupts
Starting I/O Address
Interrupt Level
Port
3F8*
IRQ04
COM1
2F8
IRQ03
COM2
3E8
IRQ04
COM3
2E8
IRQ03
COM4
*Default for serial port
Serial interface specifications include:
n
Baud rate up to 19.2 KB per second
n
Word length - 5, 6, 7, or 8 bits
n
Stop bit - 1, 1.5, or 2 bits
n
Start bit - 1 bit
n
Parity bit - 1 bit (odd parity or even parity).
INDICATOR PANEL
The indicator panel is attached to the front panel and contains the power button, suspend
button, and indicator lamps. The indicator panel attaches to the system board using con-
nector J15 (reset connector), JP15 (hard disk drive busy lamp connector), and J9 (power
lamp connector).
