IN '85 Intel's 82586 and others were already quite available, though I'm not
sure how long they'd been around. AMD's 7990 was on a board I worked back in
'84, though it was not a production part. I have an AMD 7990 on the floor here
that's copyright 1985. Since the 7990 used a separate modulator, I guess it's
really not a single-chip device, however. By late '89 there was a British
company that made a part, of which I believe I was one of the earliest users,
which was a single-chip device (called ENZO and packaged in an 80-pin (?) pqfp)
tailored for the PC-market, with a host interface and the modulator and
everything in between on board. Only the COAX interface had to be external,
which required a couple of TTL/ECL translation stages and the reverse, in
addition to the usual transformer and coax driver (which always was a costly
component!).
Dick
----- Original Message -----
From: "Tony Duell" <ard_at_p850ug1.demon.co.uk>
To: <classiccmp_at_classiccmp.org>
Sent: Sunday, April 22, 2001 11:52 AM
Subject: Re: 3Mb Ethernet
> >
> > As we all know, Ethernet was only running at 3 Mbit in the early days. When
> > was the move to 10 Mbit done and is 10Mb Ethernet backwards compatible?
>
> AFAIK it is not backwards-compatible, at least in the sense that no
> 10Mbps ethernet controller supports the 3Mbps data rate (at least, I've
> never seen one that does).
>
> > Also, were there any Ethernet controllers back in the old days, or what kind
> > of interfacing did old Ethernet capable equipment such as the SUN 1 or DECNA
> > use?
>
> There were no single-chip ethernet controllers, if that's what you're
> asking. The ethernet circuitry for the classic PERQ (which was generally
> 10Mbps, but early enough that single-chip controllers didn't really
> exist) is a 2910 sequencer, some microcode PROMs, some 9403 FIFOs, and a
> lot of TTL glue logic (and some comparator-type parts for the interface
> to the AUI connector). It takes up about 1/3rd of the EIO board.
>
> -tony
>
>
Received on Sun Apr 22 2001 - 14:51:14 BST