Wanted: PDP-11 Unibus Ethernet interface from Xerox, c. 1981
RichA at LivingComputerMuseum.org
Tue Mar 31 14:11:53 CDT 2015
From: Noel Chiappa
Sent: Tuesday, March 31, 2015 6:19 AM
> If this is the card I'm thinking of (we got two as part of the Xerox donation
> of Altos, a Dover, etc to MIT, BITD), it's to a 3-MBit Experimental Ethernet,
> not to a 10-MBit Ethernet, and so won't be much use unless you have something
> else with a 3-MBit Ethernet (and of course you'd also need 3-MBit
> transceivers, etc, etc).
I've been given further information from my WAITS advisory team. This is
indeed the card you're thinking of. Like MIT and CMU, Stanford got a donation
of a Dover printer, lots of Altos, and the 3Mbit card for the PDP-11. Stanford
put theirs into SAIL and made WAITS talk to the Ethernet through the front end.
When I went to work at Stanford LOTS in October, 1984, the campus network was
still primarily 3Mbit PUP. I installed a 10Mbit MEIS into one of our DEC-20s
as part of the beta for the updated monitor code sometime after that.
> And of courset those cards were made in very, very limited numbers; if any
> survive to this day, I will be absolutely astonished.
So will I, but I have to ask.
> If you have a pointer to the PDP-11 code, I can take a look at it and confirm
> if it's a 3-MBit card. (The hardware packet header format is completely
> different from that for a 10-MBit.)
This has only just come up in the last 36 hours, so I don't have my hands on
the code in question yet, but the rest of the evidence says that we don't need
Vintage Computing Sr. Systems Engineer
Living Computer Museum
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Seattle, WA 98134
mailto:RichA at LivingComputerMuseum.org
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