IBM PC 300GL - Manual (Page 19)

12 PC 300 GL and 300 PL
The following figure shows the serial port assignments in the configuration.
The default setting for the serial port is COM1.
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 the configuration.
The default setting for the parallel port is Parallel 1.
The system board has one connector for the parallel port. For information on the
connector pin assignments, see “Parallel port connector” on page 46.
Keyboard and mouse ports
A general purpose 8-bit microcontroller, 8042AH compatible, controls the mouse and
keyboard subsystem. 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, 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
48 and “Appendix C. IRQ and DMA channel assignments,” on page 53.
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 “Mouse and
keyboard port connectors” on page 45.
Table 4. Serial port assignments
Port assignment Address range (hex) IRQ level
Serial 1 03F8–03FF IRQ4
Serial 2 02F8–02FF IRQ3
Serial 3 03E8–03FF IRQ4
Serial 4 O2E8–027F IRQ13
Table 5. Parallel port assignments
Port assignment Address range (hex) IRQ level
Parallel 1 03BC–03BE IRQ7
Parallel 2 0378–037F IRQ5
Parallel 3 0278–03FF IRQ5