This is a closer view of the I/O ports on the motherboard. The I/O panel features two PS/2 ports, three USB connectors, one parallel port, and two serial ports. On the graphic, click the hyperlinks for more information. PS/2 ports USB ports Serial ports Parallel ports

PS/2 Ports

The keyboard and mouse ports are not interchangeable except for troubleshooting purposes. After turning the computer off, you may swap the keyboard and mouse to test if the port or the device is defective, but return them to their correct ports after you have determined the issue. Connect the mouse to the top port and the keyboard to the bottom.

The +5-volt (V) lines incorporate a PolySwitch circuit, which acts like a self-healing fuse, re-establishing the connection after an over-current condition is removed. Care must be taken to turn off the computer's power before installing or removing the keyboard or mouse.

The keyboard controller contains the keyboard and mouse controller code, provides the keyboard and mouse control functions, and supports password protection for power on or reset. A power on or reset password may be specified in the BIOS Setup Utility.

The keyboard controller also supports the hot key sequence CTRL+ALT+DELETE for a software reset. This key combination resets the computer's software by jumping to the beginning of the BIOS code and running the Power-On Self Test (POST).

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USB Ports

One USB peripheral device may be connected to each of the three USB ports. For more than three USB devices, an external hub may be connected to any of the ports. Some USB devices may even have a throughput on the plug. Port 0 is on top. Port 1 in the middle, and port 2 is on the bottom. The motherboard fully supports the Open Host Controller Interface (OHCI) and uses OHCI-compatible software drivers. USB features include:

• Self-identifying, hot pluggable peripheral devices.
  • Drivers do not have to be loaded, and the computer does not have to be reconfigured or restarted.
  • After plugging the USB peripheral device into the USB port, the peripheral device automatically becomes fully functional.

• Automatic mapping of function to driver and configuration.
• Support of isochronous and asynchronous transfer types.
• Support for 127 physical devices, as long as the cumulative bandwidth demands do not exceed 12 megabytes per second (MBps).
  • This is roughly 100 times the limit of current serial busses and is wide enough to daisy chain a printer, scanner, still camera, and removable hard disk from one port.

• Guaranteed bandwidth and low latencies appropriate for telephony, audio, and other programs.
• Error handling and fault recovery mechanisms built into protocol.
• USB keyboards and mouse devices are supported as legacy devices during startup and under operating systems without USB support.

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Serial Ports

The 16450- and 16550A-compatible Universal Asynchronous Receiver/Transmitters (UARTs) support data transfers at speeds up to 115.2 kilobits per second (Kbps) in extended UART mode. This 9-pin serial port can be configured in several different combinations in the BIOS Setup Utility.

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Parallel Port

The 25-pin D-sub header is a multi-mode, bi-directional port. The parallel port operates in normal or standard mode, Enhanced Parallel Port (EPP), and a high-speed Extended Capabilities Port (ECP) mode. The parallel port can be configured in the BIOS Setup Utility. Using a device connected to the parallel port when configured as EPP normally requires a driver for the device be installed.

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