11/70 front panel

From: Bill/Carolyn Pechter <pechter_at_shell.monmouth.com>
Date: Sat Oct 24 10:04:12 1998

> Date: Fri, 23 Oct 1998 09:15:43 -0400 (EDT)
> From: Ethan Dicks <erd_at_infinet.com>
> To: classiccmp_at_u.washington.edu
> Subject: PDP-11/70 rescued!
> Message-ID: <199810231315.JAA24826_at_user2.infinet.com>
> MIME-Version: 1.0
> Content-Type: text/plain; charset=US-ASCII
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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...
Received on Sat Oct 24 1998 - 10:04:12 BST