NE2000 ISA clone FAQ


How to deal with ISA Plug n Play cards and still have a shred of sanity left at the end of the day.


In the beginning ....

Plug and Play (PNP)


After the jumper, but before PCI there was PNP. When it was new it was a disaster. It hasn't gotten much better. It was just another weak attempt to emulate the simplicity of MAC hardware. ISA cards have two modes; jumpered and jumperless.

YOU must physically move a jumper on the card to change configuration

A Dos program is used to write the config to a flash memory on the board itself. This emulates a jumpered device. In this mode a device is usually NOT in PNP mode.


The ISA Board config problem.

Ethernet chips come from a small number of manufacturers. Those FABS sell or license the chips to other companies. The NE2000 was originally made for Novell Ethernet, (NE). The 2000 was used most likely because it was so "futuristic". The NE2000 spec became one of the most used network specs.

The ISA Ethernet board comes in a number of manufacturers chips. Most smaller manufacturers buy chips from a large chip house and rebrand them as their own. If you look at the small number of ethernet drivers that Linux distributions come with, you will notice there are not many drivers as there are ethernet cards. These many drivers cover many different network chips. Here is a list of the most commonly found NE200 chips.

Common NE2000 Chips

x-val

y-val

z-val

32.6

18.3

21.25

34.9

17.l

23.6


"Don't use addresses 0x300 or 0x320 for NE2000 type cards." [Ethernet Howto] Most ISA modules accept parameters like io=0x340 and irq=12 on the insmod command line. It is REQUIRED or at least STRONGLY ADVISED that you supply these parameters to avoid probing for the card. Unlike PCI and EISA devices, there is no real safe way to do auto-probing for most ISA devices, and so it should be avoided when using drivers as modules. [Ethernet Howto]


There are two major pieces of information needed for configuring the ISA PnP card.

Interrupts 3 and 4 are for serial ports. Five is for a second printer port or a sound card. IRQ 6 is used for the Floppy drive controller. IRQ 7 is sometimes used for sound cards but most often used for the first parallel, (printer) port. IRQ 8 is for the Real Time Clock, Don't mess with this one.

IRQ 9 is a mutant interrupt, unlike any other. IRQ 9 IS IRQ 2 in disguise. I don't think there is a network card alive today that will allow you to use IRQ2, but 9 is OK almost always. Now we come to my favorite of all interrupts. Number TEN. More to come...

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Things you should have learned in school, (had you been paying attention).

Your ISA eternet card may have up to THREE different connectors.


Credits and links:

http://www.plasma-online.de/index.html?content=http%3A//www.plasma-online.de/english/identify/serial/pnp_id_pnp.html

The ISA PNP FAQ http://www.roestock.demon.co.uk/isapnptools/

NE2000 Clone Configuration programs http://www.corbina.ru/~gasya/homelan/drivers/ne2000.htm

Linux Ethercard Status, Diagnostic and Setup Utilities http://www.scyld.com/diag/index.html