31 Mar
2015
31 Mar
'15
9:19 a.m.
From: Rich Alderson
SAIL .. did not use the MEIS (Massbus-Ethernet
Interface Subsystem) for
Ethernet connectivity, but rather a Unibus card from Xerox (apparently
used to hook -11s to D-machines) which went into the front end 11/40 on
the KL-10.
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).
And of courset those cards were made in very, very limited numbers; if any
survive to this day, I will be absolutely astonished.
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.)
Noel
3:16 p.m.
As it happens, we have one in the KS-10 which used to be MIT-AI. Once we
have the system restored to fully running condition, we'll build a little
Chaosnet to some Symbolics equipment here. (Obviously we'll run ITS on it.)
Rich
-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Al Kossow
Sent: Tuesday, March 31, 2015 6:42 AM
To: cctalk at classiccmp.org
Subject: Re: Wanted: PDP-11 Unibus Ethernet interface from Xerox, c. 1981
On 3/31/15 6:19 AM, Noel Chiappa wrote:
And of courset those cards were made in very, very
limited numbers; if any
survive to this day, I will be absolutely astonished.
I have several of them. Anyone still have Unibus Chaosnet cards?
3:11 p.m.
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
this corroboration.
Thanks,
Rich
Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computer Museum
2245 1st Avenue S
Seattle, WA 98134
mailto:RichA at LivingComputerMuseum.org
http://www.LivingComputerMuseum.org/
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3 comments
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participants (3)
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aek＠bitsavers.org -
jnc＠mercury.lcs.mit.edu -
RichA＠LivingComputerMuseum.org