puder@logic.DEC (Karl Puder) (05/15/84)
The earlier note that explained the meaning of ^P to the VAX console was
correct, but there is one additional tidbit of information that VAX users
will find very useful. (It is in the manual, but the books are so big that
they only get read to answer questions; if the question does not come up...)
Background:
On the front of the cabinet is a keyswitch with five (5) positions, labelled
(on a 750): OFF, LOCAL SECURE, LOCAL, REMOTE SECURE, REMOTE. On a 780, I
beleive they are labelled: OFF, LOCAL DISABLE, LOCAL ENABLE, REMOTE DISABLE,
REMOTE ENABLE.
Data:
The difference between LOCAL and REMOTE (as you probably know) is whether
the console is the tty line from the diagnostic processor (the little 11) or
the modem on the diagnostic line.
THE USEFUL TIDBIT:----------------------------------------------------------
The difference between ENABLE and DISABLE (== the meaning of SECURE) is that
in DISABLE (SECURE) ^P is just another character. It does not switch to
"console mode".
----------------------------------------------------------------------------
I hope this helps VAX users out there by letting them remove the "hand's
off" sign from their console terminals.
Karl.
USPS: Karl Puder, HL02-3/E09, DEC AITG, 77 Reed Road, Hudson, MA, 01749
phone: (617)568-4979 | ARPA: puder%logic.DEC@DECWRL.ARPA
DTN: 225-4979 | EasyNET: LOGIC::PUDER
UUCP: puder%logic.DEC@decwrl.UUCP
UUCP: ...!{ucbvax,decvax,ihnp4}!decwrl!dec-rhea!dec-logic!puder
Tue 15-May-1984 12:19 DSTsmh@mit-eddie.UUCP (Steven M. Haflich) (05/16/84)
puder%logic.DEC@decwrl.UUCP says: THE USEFUL TIDBIT:-------------------------------------------------- The difference between ENABLE and DISABLE (== the meaning of SECURE) is that in DISABLE (SECURE) ^P is just another character. It does not switch to "console mode". No less important is the fact that DISABLE also disables that tiny reset pushbutton. On a 750 this switch is right where it can very easily be pushed by accident when one leans against the machine. Why'd DEC have to make this machine look so much like a coffee table? Mine always looks like my desk, covered with documentation, telephones, and test equipment. Steve Haflich, MIT
mark@elsie.UUCP (05/16/84)
<>
SECURE (DISABLE on the 780) also disables the RESET button on the front of the
750's cabinet. This keeps you from accidently rebooting. I once let my three
year old daughter come into the computer room with me. I turned my back for
one second and guess what button she decided to push?
BOTTOM LINE: Always leave the console power key set at SECURE unless you
want to go into console mode, or RESET the computer.
--
Mark J. Miller
NIH/NCI/DCE/LEC
UUCP: decvax!harpo!seismo!umcp-cs!elsie!mark
Phone: (301) 496-5688billr@tekred.UUCP (Bill Randle) (05/17/84)
The very same thing holds true for PDP-11/70's with the remote diagnostic console.
henry@utzoo.UUCP (Henry Spencer) (05/20/84)
Another fun example of easily-hit switches: on the old 11/50 at CSRG
here, the stop/start switch on the swap-area RK05 was at exactly the
same height as the back support on the console chair. We eventually
moved that &$^%$*&@ chair somewhere else.
--
Henry Spencer @ U of Toronto Zoology
{allegra,ihnp4,linus,decvax}!utzoo!henrytihor@acf4.UUCP (05/22/84)
Note also that on a 750 with the RDM module a Control-D is also meaningful in some combinations of keyswitch and system state. I banged on one of ours for a while to make sure and it is also safe as long as the CPU is running and the keyswitch is in the local SECURE (not enabled) position.