1-14 Technical Information
I/O addresses and interrupt levels for the two channels are given in Table 1-8. The interrupt
level is selectable via Setup to either IRQ3 or IRQ4. Software selectable base addresses are
3F8h, 2F8h, 3E8h, and 2E8h.
NOTE:
Any interrupts used for the built-in
serial ports are not available for ISA parallel
ports.
Table 1-8 Serial Port Addressing and Interrupts
Starting I/O Address
Interrupt Level
Port
3F8h
IRQ04
COM1*
2F8h
IRQ03
COM2
3E8h
IRQ04
COM3
2E8h
IRQ03
COM4
* Disabled if fax/modem installed
Serial interface specifications include:
Baud rate up to 19.2 KB per second
Word length - 5, 6, 7, or 8 bits
Stop bit - 1, 1.5, or 2 bits
Start bit - 1 bit
Parity bit - 1 bit (odd parity or even parity).
Serial interface signals are output through the system board’s 9-pin, D-subconnector. The
connectors are located at the rear of the system unit. Pin locations for the serial interface
connector are shown in Appendix A.
POWER SUPPLY
The power supply is mounted inside the system unit. It supplies power to the system board,
option boards, diskette drives, hard disks, keyboard, and mouse. A fan inside the power
supply provides system ventilation. The power supply supplies 145 watts of power.
Connector locations are in Appendix A.
