HP Vectra User Manual

Registers
The card has three programmable registers that control the
operation of the parallel portion of the card. The system
programmer may gain
access or control any of the registers in the
parallel adapter through the 80286. The registers must be
addnessed before a read
or write operation can take place. The
following table defines the registers and their addresses.
Table 11.7
Accessible Registers
Address*
Hex Register
X78 or X7C Data Buffer Register
X7A
or X7E Printer Control Register
X79
or X7D Printer Status Register
Data Buffer Register (X78H or X7CH)
This register contains the data character. Reading from this
address
causes the character to be read by the card. Writing to
this address causes the character to be transmitted via the parallel
connector.
*The
X is substituted with the appropriate port selection number,
a 3 for port 1, a 2 for port 2.
Serial/Parallel Card 137

HP Vectra Specifications

General

Processor	Intel Pentium
RAM	Up to 128 MB
Storage	HDD (capacity varies by model)
Operating System	Windows 95
Graphics	Integrated
Ports	Serial, Parallel
Expansion Slots	ISA, PCI