I think these observations are basically correct; you can only go so far with software based security until you really have to start thinking about hardening the physical environment.

Columbia was perhaps kind of an odd case in that a rather large number of people could come waltzing through the machine room and some didn't really understand, "Don't Touch".  We systems programmers REALLY didn't feel comfortable with this.

But the security question really was, once you are in normal operation, just how 'normal' should the console be?  Tops-10's console was pretty normal except for the INITIA automatic nice things.  Tops-20's is closer as you normally can't get to the auto-magic.  My recollection is that on at least at least some IBM mainframes, you couldn't use the console for a foreground session.  I think this was the case for OS/360 (which we ran on our 91) and maybe for MVS.  I can't remember about VM.

What part of the KA10 console are you talking about, actually?  I thought a few switches did work even with run on.  My 1971 version of SYSREF (from the Orange Book, pages 138 to 143) states that some switches, such as READ IN, START, EXAMINE NEXT and DEPOSIT NEXT don't work if run is on.  However, EXAMINE THIS and DEPOSIT do work with run on, which is what I remember.

I can't remember where I put the later version of SYSREF that has KI operations.  What do you remember?

The switch register (obviously) works and WPI used it for a fun application.  We have less than 37 operations personnel assigned to our KA, and each operator had their own bit.  When they came in to work, they pressed the switch for their 'bit'.  You could run a program which would read the switch register and tell you how many operators were on duty and who they were.

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On 3/7/22 4:26 PM, Peter Lothberg wrote:
I think we are "over board", if you are standing next to the machine all bets are off.

Om the KI10, the front panel works while the CPU is running, not like KA10 where you have to halt the CPU.

On the KI you can examine/deposit anywhere, use physical addresses or go through the "MMU". You can put an instruction on the switches and press XCT and the CPU will execute that as next instruction in current context. 

Yes, there is a "front panel lock" toggle switch, but no key-lock.....

(Or walk to the back of the CPU and turn power off...)
(or shut down the air conditioner)

Even Inter CPU's have a "front end" that can be accessed if you have access to the motherboard....

-P

On 3/72022 3:56 PM, Thomas DeBellis wrote
Under Tops-10, the situation might be considered to be worse (but I believe that term to be unfair).  That is, the operating system has no control over what might be examined or deposited from the front panel.
There, the CTY is even more special: it doesn't need a password for/any/ login.  You can do an _I [1,2]_ and you are now an operator (I.E.,
root).  However, for many years, I thought this was just neat...

    What about other DEC multi-user operating systems?  Do you have 'magic' consoles?