IBM PC 300GL Type 6272, Техническое руководство

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Chapter 2. System Board Features
Input/Output Controller
Control of the integrated input/output (I/O) ports and diskette drive controller is provided by a single chip,
the National Semiconductor PC87307. This chip, which supports Plug and Play, controls the following
features:
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
Ÿ
Advanced Power Management support
The chip requires an external 24 MHz frequency.
Diskette Drive Support
A maximum of two diskette drives and one tape backup drive is supported on the system board. The
actual number of diskette drives that can be installed is dependent upon the system unit size (the
PC 300GL 6272 has three drive bays for installing devices and the PC 300GL 6282 has four drive bays
for installing internal devices). The following is a list of devices that the diskette drive subsystem supports:
Ÿ
1.44 MB, 3.5" diskette drive
Ÿ
2.88 MB, 3.5" diskette drive
Ÿ
1.2 MB, 5.25" diskette drive
One connector is provided on the system board for diskette drive support. For information on the
connector pin assignments, see “Diskette Drive Connector” on page 35.
Serial Port
Integrated into the system board are two universal asynchronous receiver/transmitter (UART) serial ports.
The serial ports include a 16-byte data, first-in first-out (FIFO) buffer, and have programmable baud rate
generators. The serial ports are NS16450 and PC16550A compatible.
For information on the connector pin assignments, see “Serial Port Connectors” on page 37.
Note: Current loop interface is not supported.
The following figure shows the serial port assignments used in configuration.
Figure 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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