IBM 6589 - PC 365 - 32 MB RAM, Manual

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Chapter 2. System Board Features
Input/Output Controller
Control of the integrated input/output (I/O) ports and diskette drive is provided by a single chip, the
National Semiconductor PC87308. This chip, which is compatible with
Plug and Play ISA
Specification 1.0, is a controller for the following:
Ÿ
Diskette drive support
Ÿ
Serial port
Ÿ
Parallel port
Ÿ
Keyboard and mouse ports
Ÿ
Infrared port
Ÿ
General-purpose I/O ports
Ÿ
Real-time clock
Diskette Drive Support
The cable provided with your computer supports a maximum of two diskette drives and one tape backup
drive (see “Internal Drives” on page 19 for more information). The following is a list of devices that the
diskette drive subsystem will support:
Ÿ
1.44 MB, 3.5-inch diskette drive
Ÿ
1.2 MB, 5.25-inch diskette drive
Ÿ
1 Mbps, 500 Kbps, or 250 Kbps tape drive
Note: A 2.88 MB, 3.5-inch diskette drive is not supported.
One 34-pin, berg-strip connector is provided on the system board for the diskette drive. For information
on the connector pin assignments, see “Diskette Drive Connector” on page 34.
Serial Port
Two universal asynchronous receiver/transmitter (UART) serial ports are integrated into the system board.
Both ports include a 16-byte data first-in first-out (FIFO) buffer, are 16550A compatible, and have
programmable baud-rate generators.
One of the UART serial ports is used in the normal mode. The other serial port is configured as an
infrared port (see “Infrared Port” on page 10).
The following table shows the default port assignments for the serial port used in the configuration.
Note: When the computer is started, the resource assignments are subject to change during the
power-on self-test (POST).
On the system board, one 9-pin, male connector is provided for the serial port. For information on the
connector pin assignments, see “Serial Port Connector” on page 35.
Table 4. Serial Port Assignments
Port Assignment Address Range IRQ Level
Serial 1 03F8h–03FFh IRQ4
Serial 2 02F8h–02FFh IRQ3
Serial 3 03E8h–03FFh IRQ4
Serial 4 02E8h–02FFh IRQ3
Chapter 2. System Board Features
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