Date   : Sun, 05 Mar 2006 12:43:25 +0000
From   : Phil Blundell <philb@...>
Subject: Re: Warning: Sad case on list!

On Sat, 2006-03-04 at 22:58 +0000, mogwai wrote:
> BTW Did anyone get around to successfully ripping the ethernet core off
> an old ISA network card and stuffing it one the 1MHz Bus? I'll have to
> have a dig through my Generally Obsolete Network Cards Box. ISTR there
> was a Western Digital 40 pin DIP Ethernet core that looked vaguely
> interesting. No DMA, Interrupt and poll jobbie. How it ever worked on an
> IBM PC/XT beats me. If identified, cards could be snapped up on ebay for
> probably a quid each.

Yeah, there are a handful of those chips that you could probably hook up
to the 1MHz bus.  I guess you're thinking of the WD8003 or some such;
the DP8390 would probably work too.  Mostly they worked by having a pile
of local buffer RAM on the card (accessed through an I/O window in the
chip) to hold transmitted and received packet data.

Nowadays, though, it might be easier to pick something a bit more
integrated like an RTL8019.  I used the CS8900 on the econet/ethernet
bridge board, which is almost perfect except that interrupts don't work
in 8-bit mode, so you have to poll it all the time.  Which isn't such a
big deal for the bridge, since its CPU is basically sitting there doing
nothing else anyway, but it would suck rather if you were trying to do
this on a BBC.

p.