Specifications

Hardware Configuration
2-13
Ribbon Connector 3M 3473-7010
Discrete Wire Connector Housing Molex 22-55-2101
Discrete Wire Connector Pins Molex 16-02-0103
Table 2-8. J4 Mating Connectors
DIN Pin Signal Name J4 Pin
1 Keyboard Clock 6
2 Keyboard Data 5
3 N/C -
4 Ground 7
5 Keyboard Power 8
Table 2-9. Keyboard DIN Connector Pinouts
2.7.2 Parallel Port (J3)
The parallel port can be used as a standard PC printer port, or it can be used for general purpose
programmable I/O. The data lines are truly bidirectional. The control lines are quasi-bidirectional.
This is discussed in Chapter 4. By using the port's input and output handshake signals, along with
its 8-bit bidirectional data lines, many types of interfaces for specialized devices can be created,
including writing data to LCD display panels, scanning keyboards, etc. Refer to Chapter 3 for
typical system software configuration information, and to Chapter 4 for hardware details regarding
nonstandard uses of this interface.
The parallel port is set to extended mode (bidirectional) at POST time. When configured in this
manner, it can be used to support a standard printer, but there is some danger of old or improperly
written software inadvertently changing the direction control bit in the parallel port control register.
If this could be a problem in your installation, use the port in its AT-mode setting. Refer to Section
4.4 for instructions on how to set the parallel port mode.
When enabled in SETUP, the parallel port is configured as the primary parallel port, at I/O address
378h-37Ah. There are no jumpers to set.
It is possible to configure a system with more than one parallel port. Using an Ampro
MiniModule/SSP (serial, serial, parallel) you can add two additional serial ports and an additional
parallel port to the CoreModule/PC. When more than one parallel port is present in a system, the
names LPT1, LPT2, etc. are assigned during system initialization. The ROM-BIOS scans for