Dell Precision 410 User Manual

Also see for Vostro 410: Setup guide User guide Service manual Setup and quick reference guide Documentation update

Contents

Hardware Configuration Features B-76HULDODQG3DUDOOHO3RUWVThe two built-in serial ports use 9-pin D-subminiature connectors on the back panel.These ports support devices such as external modems, printers, plotters, and micethat require serial data transmission (the transmission of data one bit at a time overone line).Most software uses the term COM (for COMmunications) plus a number to designatea serial port (for example, COM1 or COM2). The default designations of your com-puter’s built-in serial ports are COM1 and COM2.The built-in parallel port uses a 25-pin D-subminiature connector on the computer’sback panel. This I/O port sends data in parallel format (where eight data bits, or onebyte, are sent simultaneously over eight separate lines in a single cable). The parallelport is used primarily for printers.Most software uses the term LPT (for Line PrinTer) plus a number to designate a par-allel port (for example, LPT1). The default designation of your computer’s built-inparallel port is LPT1.Port designations are used, for example, in software installation procedures thatinclude a step in which you identify the port to which your printer is attached, thus tell-ing your software where to send its output. (An incorrect designation prevents theprinter from printing or causes scrambled print.)$GGLQJ DQ ([SDQVLRQ &DUG &RQWDLQLQJ 6HULDO RU 3DUDOOHO 3RUWVYour computer system has an autoconfiguration capability for the serial ports. Thisfeature lets you add an expansion card containing a serial port that has the same des-ignation as one of the built-in ports without having to reconfigure the card. When thecomputer detects the duplicate serial port on the expansion card, itremaps (reassigns)the built-in port to the next available port designation.Both the new and the remapped COM ports share the same IRQ setting, as follows:COM1, COM3: IRQ4 (shared setting)COM2, COM4: IRQ3 (shared setting)These COM ports have the following I/O address settings:COM1: 3F8hCOM2: 2F8hCOM3: 3E8hCOM4: 2E8hFor example, if you add an internal modem card with a port configured as COM1, thecomputer then sees logical COM1 as the address on the modem card. It automati-cally remaps the built-in serial port that was designated as COM1 to COM3, whichshares the COM1 IRQ setting. (Note that when you have two COM ports sharing anIRQ setting, you can use either port as necessarybut you may not be able to use themboth at the same time.) If you install one or more expansion cards with serial ports des-ignated as COM1 and COM3, the corresponding built-in serial port is disabled, asdescribed in “Serial Port 1 and Serial Port 2” in Chapter 3.23205BK0.BK : 23205AB0.FM Page 7 Wednesday, March 18, 1998 1:51 PM