This document explains how to change your printer ports to accommodate different printers. It also explains how to view and change COM ports and definitions for related terms found in the Setup program.
This document is not intended to be a troubleshooting document. It is an overview of the options provided for enabling or disabling devices and working with parallel and serial port options in the system setup menu.
Understanding printer ports or parallel ports
The place in the setup program that controls the printer or other parallel type devices is called the parallel port. There are multiple parallel ports. Each can be configured manually or by the automatic setup functions available within the setup (CMOS) program. If the parallel ports are enabled, a parallel device such as a printer will be found by your PC utilizing Plug and Play technology. If these ports are disabled, any added device must be configured manually and will not automatically be found by your computer. Parallel port addresses range between LPT1 (printer port # 1) through LPT3 and are designed to use specific IRQ settings. The Novice consumer should not change these settings or addresses. The automatic/enabled settings should remain consistent to insure future appropriate settings by the Plug and Play setup of your HP Pavilion PC. The following are the types of parallel ports:
- Output - 4 bit transfer rate - One-way communication only, such as from the PC to the printer with no return communication loop.
- Bidirectional - 8 bit transfer rate - This port was designed to operate as either a one-way (output only) or a two-way communication port. Some low-end printers require the bidirectional port option due to the need for slower printing speed settings.
- EPP - Enhanced Parallel Port - The EPP port is especially designed for parallel port peripherals such as LAN adapters, disk drives and tape back-up storage devices. Some printers are designed to utilize this port type for communication, but they are limited in number.
- ECP - Enhanced Capabilities Port - The ECP port was designed specifically to support an inexpensive attachment to a high performance printer. The ECP port allows the benefit of bidirectional communication and software driven printer programs.
Understanding COM ports or Serial ports
A COM port is not a physical component. A COM port is comprised of two values, called I/O address and the IRQ, which is assigned to a serial port.
COM ports or serial ports are used for hardware such as your modem, in some cases a high-end sound card, your mouse (not a PS/2 mouse), fax machines and other hardware devices that require a dedicated address and IRQ setting. These items are dedicated, because they are used by multiple software programs, the Internet, as well as being a stand-alone device. The COM port or serial port is not used for the connection of a printer or parallel device, with the exception of some very old DOS-type printing devices.
How to change ports, and enable or disable devices using the CMOS or Setup program
The software, for the device purchased or being added to your PC, should provide the instructions needed to understand which port type to connect and whether or not the items port should be enabled or disabled. Many peripheral items require different connections. The following is an overview of where and how to change the ports or enable/disable devices. Please utilize the manufacturer’s suggestions on what changes will be needed prior to changing ports or disabling devices.
Changing items in the setup menu can result in the loss of function of other devices due to conflicts or wrong changes. Please make a written note of the current settings prior to making any changes so the past or prior settings can be re-entered in the event there is a problem during the installation of your device.
How to make changes in the setup (CMOS) of your Compaq Presario PC
Changes can be made using the CMOS built into the computer.
- Shut down any running programs and choose Start , Shut Down , and Restart the Computer .
- When the red Compaq logo appears, press the F10 key on the keyboard to enter setup.
- Press the Right Arrow key to select Advanced . This brings up the configuration options.
- Press the Down Arrow key:
- To enable/disable or make changes to serial port information, stop in the applicable field and press the Enter key to view options.
- To enable/disable parallel/printer ports, stop in the Parallel port field and press the Enter key to view options.
- To change the parallel/printer port type, stop in the Peripheral Configuration option field and press the Enter key to view options.
- Use the Down Arrow key to choose the setting and press Enter to select the change.
- Press the F10 key to save the new setting and exit setup, then press the Enter key again to choose Yes for saving settings.
- The system will finish starting into Windows.
NOTE:In some cases it may be required to remove a port setting in Windows and change the setup (CMOS) settings for a device to recognize that a change has been made. This type of issue can arise if a printer has been added using the wrong port and then trying to change the port settings after the installation. It is advised, in this case, to remove the printer settings in Windows, change the setup (CMOS) settings, then reinstall the printer.
How to remove port settings in Windows
It should only be necessary to remove port settings in Windows, it should never be necessary to add or change port settings within Windows. The changes made to the setup program will be seen after a successful installation of a device.
- Right-click My Computer and select Properties .
- Choose the Device Manager tab.
- Choose the + sign next to the port(s) (COM and/or LPT).
- Highlight the port (for example LPT1) and choose the Remove button.
- Choose OK to confirm the removal.
- Close the System Properties window.
- Choose Start , then Shutdown and use the instructions listed in this document for making changes to the setup (CMOS) configuration prior to restarting the PC.