IBM PC 300GL Type 6272, Техническое руководство

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Chapter 2. System Board Features
Parallel Port
Integrated in the system board is support for extended capabilities port (ECP), enhanced parallel port
(EPP) and standard parallel port (SPP) modes. The modes of operation are selected through the
Configuration/Setup Utility program with the default mode set to SPP.
The following figure shows the parallel port assignments used in configuration.
The system board has one connector for the parallel port. For information on the connector pin
assignments, see “Parallel Port Connector” on page 37.
Keyboard and Mouse Ports
The keyboard and mouse subsystem is controlled by a general purpose 8-bit microcontroller; it is
compatible with 8042AH. The controller consists of 256 bytes of data memory and 2 KB of read only
memory (ROM).
The controller has two logical devices: one controls the keyboard and the other controls the mouse. The
keyboard has two fixed I/O addresses and a fixed IRQ line and can operate without the mouse. The
mouse cannot operate without the keyboard because, although it has a fixed IRQ line, the mouse relies on
the addresses of the keyboard for operation. For the keyboard and mouse interfaces, no resource
assignments are given in the system memory addresses or DMA channels. For information on the
resource assignments, see “Input/Output Address Map” on page 45 and Figure 52 on page 50 (for IRQ
assignments).
The system board has one connector for the keyboard port and one connector for the mouse port. For
information on the connector pin assignments, see “Keyboard and Mouse Port Connectors” on page 38.
Figure 5. Parallel Port Assignments
Port Assignment Address Range IRQ Level
Parallel 1 03BCh–03BEh IRQ7
Parallel 2 0378h–037Fh IRQ5
Parallel 3 0278h–027Fh IRQ5
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Technical Information Manual