Options : 3BCh/IRQ7, 278h/IRQ5, 378h/IRQ7, Disabled

This function allows you to select the I/O address and IRQ for the onboard parallel port. The default I/O address of 378h and IRQ of 7 should work well in most cases so unless you have a problem, you should just leave it at the default settings. Only select an alternative I/O address or IRQ if you are facing configuration problems with the parallel port.

Options : ECP, EPP, ECP+EPP, Normal (SPP)

This feature is usually found under the Onboard Parallel Port option. It's linked to the parallel port so if you disable the parallel port, this feature will disappear from the screen or appear greyed out.

There are four options. The default value is Normal (SPP) which will work with all parallel port devices but is very slow. Two faster bidirectional modes are available, namely the ECP (Extended Capabilities Port) and EPP (Enhanced Parallel Port) modes. ECP uses the DMA protocol to achieve data transfer rates of up to 2.5Mbits/s and provides symmetric bidirectional communication. On the other hand, EPP uses existing parallel port signals to provide asymmetric bidirectional communication.

Generally, because of its FIFOs and the DMA channel it uses, ECP is good for large data transfers (useful for scanners and printers). On the other hand, EPP is better with links that switch directions frequently (like parallel port drives). This tip was obtained from Jan Axelson's Parallel Port FAQ so check it out if you require more information on parallel ports. However, the manufacturer of your parallel port peripheral may have designated a preferred parallel port mode. In that case, it's best to follow their recommendations.

For those who don't know what mode to select but at least know that their parallel port device supports bidirectional transfers, the BIOS offers the ECP+EPP mode. If you select this mode, then the parallel port device will be able to use either one of those modes. However, this should be considered as a last resort as you may be needlessly tying up an IRQ for nothing (if your device does not use ECP at all) or your BIOS may not select the best parallel port mode for the device. If possible, set the parallel port to the transfer mode that best suits your parallel port device.

ECP Mode Use DMA

Options : Channel 1, Channel 3

This feature is usually found under the Parallel Port Mode option. It's linked to that option so if you did not enable either the ECP or ECP+EPP mode, this feature will disappear from the screen or appear grayed out.

You can use this feature to select the DMA channel of your preference. Normally, the default value of DMA Channel 3 will work just fine. You should only select the alternative value of Channel 1 if there's a conflict with another device.

EPP Mode Select

Options : EPP 1.7, EPP 1.9

This feature is usually found under the Parallel Port Mode option. It's linked to that option so if you did not enable either the EPP or ECP+EPP mode, this feature will disappear from the screen or appear grayed out.

You can use this feature to choose which version of EPP to use. For better performance, use EPP 1.9. But if you are facing connection issues, try setting it to EPP 1.7. Most of the time, EPP 1.9 will work perfectly well. For more information, check out KasperPedersen's explanation :-

In the EPP protocol, the port asserts a request strobe (I want to read/write). The attached device reads the data, and asserts an acknowledge strobe (I have taken/provided the data). The port then negates the strobe (operation done). Finally the attached device negates its acknowledgement (I'm ready for another operation).

The difference between 1.7 and 1.9 is the last state where the attached device removes the acknowledge strobe. 1.7 ports don't check that the device has negated the acknowledge strobe, but presumes that the device will have removed it when 125ns have passed. This can be a problem if cables are long.

This was fixed in 1.9: Before it starts a cycle, it waits for the attached device to negate the acknowledge strobe from the last cycle. This allows for a cleaner hardware design at the device end; and longer cables (50m possible if IEEE1284 is used, even though that's outside the specs.)

It sums down to that setting the port for 1.9 is compatible with previous 1.7 devices, but setting the port for 1.7 will cause problems with 1.9 devices or long cables. The reason it's an option at all is that "some" 1.7 devices won't cope with a new cycle less than 125 ns after the port has negated the request strobe. This is to be considered a hardware bug in the device.

Dekeonus provided this piece of information from Warp Nine Engineering - The IEEE 1284 Experts :-

The EPP protocol was originally developed by Intel, Xircom and Zenith Data Systems, now refered to as EPP1.7 (in reference to a Xircom proposal version 1.7) EPP1.9 (more correctly 1284 EPP) was the protocol that was adopted as one of the IEEE 1284 advanced modes.

The EPP1.7 mode is provided for backward compatibility as a 1284 EPP compatible peripheral will work properly with an EPP 1.7 version host adapter, but an EPP 1.7 peripheral may not operate properly with a 1284 compliant host.

USB Mouse Support

Options : Enabled, Disabled

This function enables or disables support for a USB mouse. Enable it if you are using a USB mouse. Otherwise, disable it.

Options : OS, BIOS

This option determines whether the USB mouse is supported via the operating system or the BIOS. Support via OS offers better functionality but at the expense of zero functionality in DOS. So, if you use real mode DOS, set the option to BIOS so that you can use the USB mouse in DOS without the need to install a driver.