HP Compaq dc7100 DT Technical Reference Manual page 102

Input/Output Interfaces
Parallel Interface Control
The BIOS function INT 17 provides simplified control of the parallel interface. Basic functions
such as initialization, character printing, and printer status are provide by subfunctions of INT
17. The parallel interface is controllable by software through a set of I/O mapped registers. The
number and type of registers available depends on the mode used (SPP, EPP, or ECP). Table 5-14
lists the parallel registers and associated functions based on mode.
I/O
Address
Base
Base + 1h
Base + 2h
Base + 3h
Base + 4h
Base + 5h
Base + 6h
Base + 7h
Base + 400h
Base + 400h
Base + 400h
Base + 400h
Base + 401h
Base + 402h
Base Address:
LPT1 = 378h
LPT2 = 278h
LPT3 = 3BCh
5-16
Table 5-14.
Parallel Interface Control Registers
Register
Data
Printer Status
Control
Address
Data Port 0
Data Port 1
Data Port 2
Data Port 3
Parallel Data FIFO
ECP Data FIFO
Test FIFO
Configuration Register A
Configuration Register B
Extended Control Register
SPP EPP
Mode Mode
Ports Ports
LPT1,2,3 LPT1,2
LPT1,2,3 LPT1,2
LPT1,2,3 LPT1,2
-- LPT1,2
-- LPT1,2
-- LPT1,2
-- LPT1,2
-- LPT1,2
-- --
-- --
-- --
-- --
-- --
-- --
361834-002
ECP
Mode
Ports
LPT1,2,3
LPT1,2,3
LPT1,2,3
--
--
--
--
--
LPT1,2,3
LPT1,2,3
LPT1,2,3
LPT1,2,3
LPT1,2,3
LPT1,2,3
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