24 Oct
1998
24 Oct
'98
3:04 a.m.
Date: Fri, 23 Oct 1998 09:15:43 -0400 (EDT)
From: Ethan Dicks <erd(a)infinet.com>
To: classiccmp(a)u.washington.edu
Subject: PDP-11/70 rescued!
Message-ID: <199810231315.JAA24826(a)user2.infinet.com>
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The Computer Quonset Hut has its first aquisition - a pair of PDP-11/70's
with peripherals.
Lucky guy.
My biggest disappointment is that the CPUs have the
corporate front panel,
not the programmer's front panel. Anyone have a spare front panel they
want to trade? ;-)
Actually the panel is better in some ways (except looks) than the 11/70
front panel.
I do prefer the DECdatasystem 570 (I think) 11/70 blue corporate
cabinet front panel for style. (The 11/74 used almost the same
front panel -- YES I did work with an 11/74 in DEC Princeton...
They did exist...
The "programmer's" front panel doesn't exist for the PDP11/70.
What you probably have is the 11/70 Remote Diagnostic Console
which allowed DEC to remotely diagnose the 11/70 (even when hung
in a microcode loop or power fail routine) from Colorado.
The front panel hooks to a microprocessor controlled card which interfaced
to a 300 or 1200/300 baud DEC or Racal Vadic modem (in auto answer
mode) when the key is in remote. Colorado would run a diagnostic chain,
examine the bus, read error logs etc.
-ethan
P.S. ISTR that PDP-11/70's and VAX-11/750's use the same hex-height 39-bit
ECC memory boards. Is this true? I know that 750's had 256K and 1Mb
boards (and eventually 4Mb boards), but every jump up required a new
memory controller (and backplane wires ;-) What's the scoop on the 11/70?
They do use the same ones... I don't think the 11/70 supported more than
the 256k MS-11K boards, though.
Bill
ex-DEC Field Service...