On Tue, 18 May 2004, Daniel <craylon@swipnet.se> wrote:
> I'm trying to install NetBSD over FTP on a 486 with a NE2000 compatible 
> card.
> Manual says that it only detects NE2000 if it has settings   irq 9 port 
> 0x280, or irq 10 port 0x300..
> The jumper only supports irq 10, 5,7,blabla. but not 9. And it's not 
> detected...
> There are 2 other jumper arrays but they're cryptic.
> what does "port" mean anyway?

"Port" means I/O port on the i386 archtecture.  It's a way for the CPU to
communicate with devices on the bus.  Data are passed through ports
to/from the device.  Obviously, the device has to be configured to use the
port(s), and the driver (in this case, the NetBSD kernel) has to know
which device is to be found at which port.  

The NIC will use the IRQ to interrupt the kernel, which will then
communicate with the NIC via the port.  

The NetBSD kernel attempts to discover the installed hardware by "probing"
i.e., trying to communicate with what might be there by testing some
likely places.  In the case of your NE2000, it tries the combinations you
indicated; it does not try every combination known to man, not even every
combination supported by the card.  

(The PCI bus self-configures, by the way.  It's because you're using an
ISA bus that you have to work this all out for yourself.)

It is possible to compile a NetBSD kernel with built-in knowledge of where
a device will be, making it unnecessary to probe.  However, for
installing, it is much easier to configure the device to use settings that
you know the kernel will try.  For antique hardware, though, that
sometimes means finding the floppy disk and/or manual that came with it.  

Hoppas det hjälper.

--jkl