It is so much easier today. Back then, we had to execute a number of
instructions to alter the lights. It took some effort to find the right
sequence to leave only a word without extraneous lights.
Regards,
Richard Schuh
________________________________
From: The IBM z/VM Operating System
[mailto:[EMAIL PROTECTED] On Behalf Of McKown, John
Sent: Monday, August 04, 2008 11:55 AM
To: [email protected]
Subject: Re: Immediate instructions (was "nonames")
Reminds me, vaguely, of putting x'DEADBEEF' in the PSW with the
WAIT bit on (hard wait). But I don't remember what system did that. It
is now one of my favorite things to put in R15 before abending (S0C1).
--
John McKown
Senior Systems Programmer
HealthMarkets
Keeping the Promise of Affordable Coverage
Administrative Services Group
Information Technology
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________________________________
From: The IBM z/VM Operating System
[mailto:[EMAIL PROTECTED] On Behalf Of Schuh, Richard
Sent: Monday, August 04, 2008 1:51 PM
To: [email protected]
Subject: Re: Immediate instructions (was "nonames")
The 7080 had a fairly large array of lights. At EOJ,
there was always a single successful completion written to the console,
or a few messages describing the error if unsuccessful. Following a good
completion, we sometimes tried to write routines that would end with a
word spelled out in the lights. A popular word was "TILT". "OOPS" was
also popular, but a bit trickier to create. We didn't mess with the
machine status if there was a problem - we didn't want to destroy
anything that might be pertinent to the debugging effort. After all, we
would have been shooting at our own toes.
Regards,
Richard Schuh