|Why is the onboard parallel (LPTx) port disabled in the bios Setup? |
If you disabled it because you couldn't get Windows to recognize something that was plugged into it.....
- all modern parallel port devices require that the mode of the onboard (built into the mboard) parallel port in the mboard's bios be set to EPP, ECP, or EPP/ ECP mode in the bios . Usually EPP mode works fine. ECP mode requires that a spare dma channel be available - sometimes it isn't.
That is often set to Standard or Bi-directional or similar in the mboard's bios by default - that will not work with modern devices.
That setting is near where you can enable / disable the parallel port, or near where you can change it's I/O address or IRQ or it's LPTx number.
(A PCI parallel port card is already set to use EPP, ECP, or EPP/ECP mode.)
- many, if not all, modern parallel port connected devices require that you use a parallel cable rated to conform to IEEE1284 specs. That IEEE1284 should be on the cable or on the end connectors, otherwise the cable may not work properly with the device. If the cable is not marked, an unmarked cable MAY work okay - the fatter the cable, the more likely it will work, because part of the IEEE1284 spec requires a greater minimum wire gauge of the individual wires (lower numbered gauge = thicker wire).
Windows numbers parallel ports - LPT ports - according to which I/O address and IRQ (Resources) it is using.
The legacy setting is LPT1 is always assigned to one that uses IRQ 7 and I/O address 0378.
In Windows 95 and up, you may not need IRQ 7, but the I/O address must be 0378 for LPT1.
If you need that IRQ 7, it must not be being used by any other PNP device (usually it isn't).
When you change the I/O address in Device Manager for the LPT port to 0378, save settings, Windows will rename the parallel port to LPT1 if it isn't already LPT1.
Go to Device Manager.
E.g. RIGHT click on My Computer - Properties - Hardware - Device Manager
Open up the Ports listing, double click on the LPTx listing, choose the Resources tab.
Click on the small box before
Use automatic settings
to remove the checkmark.
In the box beside
Settings based on
choose one of the configurations, other than Current Configuration, that has 0378 as an I/O address.
E.g., on my computer, Basic 0000 is 0378, another I/O address is for ECP mode, IRQ is ?
Many printers and many multifunction printer etc. devices don't require you set an IRQ, but some other devices do.
If your device requires IRQ 7, click on IRQ ? to highlight it, and choose IRQ 7, click on OK..