Registers; Accessible Registers - HP Vectra Reference Manual

Registers
The card has 11 programmable registers that control the
operation of the serial portion of the card. The system
programmer may gain access or control any of the registers in the
serial adapter through the 80286. The registers must be
addressed before a read or write operation can take place. The
following table defines the registers and their addresses.
Table 11.2
Accessible Registers
Address*
Hex
XF8
XF8
XF8
XF9
XF9
XFA
XFB
XFC
XFD
XFE
XFF
Register
Transmit Buffer
Receive Buffer
Divisor Latch LSB
Divisor Latch MSB
Interrupt Enable Register
Interrupt Identification Register
Line Control Register
Modem Control Register
Line Status Register
Modem Status Register
Reserved
*The X is substituted with the port selection number, a 3 for port
1, a 2 for port 2.
124 Serial/Parallel Card