HP Compaq dc7100 DT Technical Reference Manual page 99

The serial interface configuration registers are listed in the following table:
Index Address
30h
60h
61h
70h
F0h
Serial Interface Control
The BIOS function INT 14 provides basic control of the serial interface. The serial interface can
be directly controlled by software through the I/O-mapped registers listed in Table 5-12.
COM1 COM2
Addr. Addr.
3F8h 2F8h
3F9h 2F9h
3FAh 2FAh
3FBh 2FBh
3FCh 2FCh
3FDh 2FDh
3FEh 2FEh
Technical Reference Guide
Table 5-11.
Serial Interface Configuration Registers
Function
Activate
Base Address MSB
Base Address LSB
Interrupt Select
Mode Register
Serial Interface Control Registers
Register
Receive Data Buffer
Transmit Data Buffer
Baud Rate Divisor Register 0 (when bit 7 of Line Control Reg. Is set)
Baud Rate Divisor Register 1 (when bit 7 of Line Control Reg. Is set)
Interrupt Enable Register
Interrupt ID Register
FIFO Control Register
Line Control Register
Modem Control Register
Line Status Register
Modem Status
Table 5-12.
361834-002
Input/Output Interfaces
R/W
R/W
R/W
R/W
R/W
R/W
R/W
W
W
W
R/W
W
R/W
R/W
R
R
R
R
5-13