herb miller

After my first year at University I worked on shift as a computer operator, in Building E machine room.

My job involved
– typing “k e,1” to clear a line from the Master terminal of a System 370 running MFT.
– sitting behind a line printer fanning the greenline paper into the box
when the page ejects were happening faster than the paper feed could handle it
– or performing tape labelling – wiping tapes so they could be re-used.

The tape drives were those big things you see in 70’s films
with electrically powered sliding glass windows
that closed automtically so that the tapes could be pulled into loops by a vacuum
– ensuring that they didn’t tension the tape too quickly and snap it.

Late one night I was led to a tape drive and demonstrated the
safety aspects of the sliding glass window.

There was a sensor that would detect an object preventing the window from closing.
When the circuit was broken the motor would automatically reverse and the window
would go down. There was a replaceable fuse in the door that, if removed would
cause the window to lock in place.

Well, I was to learn that someone had discovered that if you pushed an arm through the glass
past the elbow and removed the fuse at just the right time, you could effectively trap a person by their arm.I was not the discoverer; I was the person with the arm.

They locked me in and went out to the kermits for a coffee break.

I started getting worried…
– who’s going to type “k e,1”
– who’s going to fan the paper in that printer
– what if there’s a fire and the sprinklers come on and I get electrocuted

I was determined to escape.
I opened another tape drive door, took the fuse from that and replaced the missing
fuse from my door. Freedom!

Trouble is, I can’t lie very well.
So I told my captors how I’d escaped.

Next day both arms were trapped.

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Unfortunately I have never seen such a list. But I’m prepared to start one.

If you’re the asker

– find the “stupid question asker” and start explaining the problem to them.
You’ll realise your mistake quite quickly

– if you’re worried that that it could be a silly mistake, and not worth being awarded “the plank”
if it becomes public, then start adding debug statements.
In the PL/1 days I used to write “put skip list” statements
In C you write printf’s or the equivalent macro or function call.
In my experience you’ll notice the problem the minute you’ve finished writing the debug lines,
even before the code has been compiled and run.

– ask yourself the following:
has it ever worked
did it actually work last time
what have you done?
did you recompile the program
did you relink the program
did you actually change the program
are you running the program you thought you’d changed
are you looking at the right output
have you changed the inputs
does the code match the comments. if not, which is wrong
is it repeatable. if not, give up until it is

You can ask these questions in whatever you order you feel necessary and
as many times as you like until you find the solution


If you’re the askee

– do the google search that the askee should have done
– ask them if they have reduced the problem to the simplest version that exhibits the bad behaviour
– ask them if they have you compared the results with the most recent regression test
– ask them to repeat the problem on another machine


If you’re the “stupid question asker”, ask the asker
– “Can you explain it to me again?”
– “Are you sure that’s the problem?”
– “Does it make any difference what day of the week you run it”
– “Did you reload the data from yesterday’s dump”
– “Does it work on Windows?”
– “Would you expect it to work when ‘whatever’ is not available?”


If you happen to be the project manager you can add these
– “When will you have a fix for it?”
– “If this went into production what severity would it be?”
– “Do you have a work around?”
– Ask them if they have asked the expert. This is a particularly good question if you know the programmer IS the expert.



If you’re just earwigging someone else’s conversation, tell them
– “It’s not possible, you have to rewrite it”
– “I had that problem yesterday but it went away when I upgraded to version blah of thingummy”
– “It works fine on Windows”
– “You need to get trace output”
– “Ask them for a dump”

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