![background image](http://html.mh-extra.com/html/nec/powermate-vp75/powermate-vp75_user-manual_248723030.webp)
Technical Information 1-15
Parallel Interface
The system has a 25-pin parallel port on the system board. Specifications for this port conform to
the IBM-PC standards.
The BIOS has automatic ISA printer port sensing. If the BIOS detects an ISA printer port
mapped to the same address, the built-in printer port is disabled. The BIOS also sets the first
parallel interface port it finds as LPT1 and the second port it finds as LPT2. The interrupt is se-
lected to either IRQ5 or IRQ7 via the Setup and jumper settings.
Interrupt levels for the parallel port are given in Table Section 1-6. Software selectable base
addresses are 3BCh, 378h, and 278h.
Parallel interface signals are output through the system board's 25-pin, D-subconnector. The con-
nector is located at the rear of the system unit. Pin locations for the parallel interface connector
are shown in Appendix A.
NOTE:
Any interrupts used for the built-in
parallel port are not available for ISA parallel ports.
Table Section 1-6 Parallel Port Addressing and Interrupts
Starting I/O Address
Interrupt Level
Port
378
IRQ05
LPT1
278
IRQ05
LPT1 or LPT2
3BC
IRQ05
LPT1 or LPT2
378*
IRQ07
LPT1
278
IRQ07
LPT1 or LPT2
3BC
IRQ07
LPT1 or LPT2
*Default for parallel port
Serial Interface
The system has two standard serial ports (COM1 and COM2). The serial ports support the
standard RS-232C interface (16550 compatible). I/O addresses and interrupt levels for the two
channels are given in Table Section 1-7. The interrupt is selectable via Setup to either IRQ3 or
IRQ4. Software selectable base addresses are 3F8h, 2F8h, 3E8h, and 2E8h. Serial interface sig-
nals 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.
Содержание PowerMate VP75
Страница 147: ...Desktop Repair 5 21 ...
Страница 173: ...Minitower Repair 6 25 ...