IBM PC 300GL Types 6275, Информационное руководство

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Headphone Connection for headphones or powered external speakers
joystick/MIDI Connection for a joystick or a MIDI device
Note: When either headphones or speakers are connected to the headphone jack, the
internal computer speaker is disabled.
There might also be an internal speaker and connections on the system board for attaching
it to the CD-ROM.
To take advantage of the audio feature, some computers come with ViaVoice. ViaVoice is
continuous speech dictation and desktop navigation software available on CD-ROM. For
more information, see the READ1ST.TXT file in the appropriate language folder on the
ViaVoice CD-ROM.
Serial Port
Your computer comes with a serial port. The serial port is used to communicate with
devices such as printers, plotters, and modems designed for the serial interface. Some
modems are installed inside the computer; others are attached externally using the
serial-port connector. For example, you can connect an external modem to a serial port in
order to communicate with other computers over telephone lines.
The serial port transfers data one bit at a time at speeds ranging from 300 to 115 000 bits per
second (bps). The serial ports are 16550-UART (universal asynchronous
receiver/transmitter) compatible so they can support high-speed modems.
You can increase the number of serial ports by installing a serial adapter in one of the
expansion slots.
Operating systems and application programs often designate serial ports with the name
COM (communication). Many programs use COM1, COM2, COM3, and COM4 in their setup
commands or menus to identify serial ports. When setting up your applications, you might
have to identify the COM port to which a particular device is connected. Also, if you are
adding a serial adapter or modem, you might have to configure the adapter or modem for a
specific COM port. This might involve setting switches on the adapter or modem as well as
changing settings in the Configuration/Setup Utility Program.
The serial connector in your computer can use any of four available port settings, provided
that a different setting is used for each. The settings include the port address (in
hexadecimal) and the IRQ (interrupt request line), which determines how the microprocessor
responds to an interrupt from the serial port.
The four available port addresses are (in hex):
3F8
2F8
3E8
18 I/O Features