The only input to the IBM 610 at the University of Notre Dame
in October, 1959, was the standard 5-hole teletype paper tape.
Sophomore Year, Fall, 1959.
Fiftieth Anniversary of Digital Computing at the University of Notre
Dame, 2009:
In September, 1959, I was a sophomore at Notre Dame, taking EE 101,
the basic Electrical Engineering Circuits course with class three days
a week, and an associated Laboratory on Tuesdays. The first week's
Lab project had us measuring voltages and currents with many very old
and some new meters, each with a different ohms-per-volt
characteristic, comparing their accuracy, and we learned how to
prepare a formal report of an experiment. The second week's lab
experiment was to calculate the value of the Determinant of a
four-by-four matrix, primarily to show us the difference between
engineering and math. The corresponding math class we were all taking
would have the professor show us by Cramer's Rule how to calculate the
value of a linear system by dividing the determinant of matrix A by
the determinant of B to get the blackboard answer
X = [A] / [B] = 7
but this second week's lab project was to demonstrate that the actual
work of an engineer would be to calculate each of those determinants,
which involved a great deal of arithmetic and was not quite as simple
as the Math Prof's immediate answer.
As the EE Lab Professor (name now forgotten, but rather aged as I
recall) finished the instructions for that lab project, he said "I
have been instructed to read this note to all EE students", and
picking up a one-page, dittoed notice, he continued "The IBM
Corporation has donated a Model 610 digg-it-tal, er, digital,
computer, located in room 240, and students can sign up for blocks of
time to use it." Slamming the sheet of paper face down, he then said
"those digital things will never amount to anything, but next year, as
Juniors, you will be able to go across the hall to room 241 and use
the Bendix G15 Analog Computer - that's how we Electrical Engineer's
solve real problems!"
In 2013, John Ehrman took Judy and I thru the Computer Museum in
California, where I related this story and saw their Bendix G15
computer, but it is described as a digital computer, but I was still
certain of my story. Then, in 2014, I posted this first experience
to the IBM-Main forum, and one respondant said the G-15 was digital.
Fortunately, my story was proven when a poster noted that if the
B-15 had the optional DA-1, Differential Analyzer hardware, it
provided all of the analog hardware, the potentiometers and meters,
and plugboard circuitry that made it function as an analog computer,
even though all of the underpinnings that processed the data were
digital circuits and the old prof would have seen it only as an
analog computer.
P.S. In those early years, there WERE problems far more suited to
analog computation, especially analysis of transients, before
the speed of digital computers, and tools like the Fast Fourier
Transform, were able to sample sufficiently fast to eliminate
the analog advantage.
So I decided to investigate this IBM Digital Computer, and went to
room 240, which was on the left at the end of the hall that opened to
the very large lab with scores of motors and motor-generator that had
its large doors open to the warm September afternoon. I looked thru
the small window in the door and saw a 3 foot high, 5 foot wide gray
machine to the left of a table with a Selectric typewriter, and saw
someone who I assumed to be a junior/senior, leaning over the
typewriter. I opened the door to enter. As the door unhinged, so did
the student, shouting "Shut that G.D. door!" as he strode across the
room to the door, flailing his arms. As he stepped out into the hall
screaming "Didn't you read the damn sign?” he then saw that his
hand-written sign to "Get The Operators Permission Before Entering"
had fallen, face down on the floor. Calming, he informed me that you
must get the operator's attention, because the computer room was air
conditioned for the vacuum tubes and he needed to put the machine in
"QUIESCE/STOP" mode (which took 5-10 seconds), as only then was it
safe shuffle in, slowly, so as to not bring in warm air. The vacuum
tubes were so temperature sensitive, that air currents would cause
computation to fail, requiring a program restart.
He pointed me to the IBM manuals on the table beside the Selectric,
and I began to read, at page one. Several hours later, I had learned
how to punch the paper tape input (like the paper tape used in
Radioteletype at my ham radio station), and could print the tape on
the Selectric, and had used the IBM example to add 2 + 2 and print 4,
and I decided I would program the calculation of the determinant on
this new toy. I spent several hours each day, with no one else
entering the computer room, and by Saturday afternoon, I had punched
my program, had printed it, and was now ready to actually run my first
computer program. As I watched the nearly 30 feet of paper tape whir
thru the reader on the 610, its panel of nixie tubes flickered with
the address numbers. I recall crossing my arms and thinking "Wow, it
is 1959, I am a sophomore at Notre Dame, and I am running a real
program on a digital computer". The paper tape came to its end, the
printer came alive, and I received my first computer output; four
characters were printed, and the Selectric shut down:
WOW!
Of course, I didn't have the slightest idea of what was wrong, or how
to debug, so I remained in the computer room until after midnight
Saturday, then were back at 7am on Sunday, and finally, that senior,
(who, I'm very sorry to say, never gave his name, and I never saw him
again) happened by, and he examined the problem with me. He
discovered that I had kind of completely missed the difference between
"program" and "data", and that the first punch in the tape was a
control character that put the 610 in a scan mode to read the tape
until another control character was found, and that in the fifth from
end position it found a control character that changed the mode from
"scan" to "print" the characters on the tape, interpreting them as
machine instructions, and what had been printed out were the last four
computer instructions in my program:
W=Carriage Return,
O=Line Feed,
W= Carriage Return,
!=Print Accumulator!
(I had found the IBM recommendation to use two carriage returns to
ensure that the very slow print head on the Selectric was all the way
back to the left margin before printing a result!).
Fortunately, by late on Monday, I had actually figured out how to run
the program, and successfully computed the value of the 4x4
determinant, and on Tuesday (I think Sept 29, 1959) I submitted the
very first EE laboratory report at Notre Dame that used a digital
computer. While the report was accepted, (and correct), I saw nothing
but chagrin in that professor's face, and as I was never encouraged by
him or anyone else on the faculty, that was also my last use of a
computer while at Notre Dame.
-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf
Of Mike Myers
Sent: Friday, January 13, 2017 3:26 PM
To: [email protected]
Subject: Re: Paper tape (was Re: Hidden Figures)
For the education of the newbies, I'm going to take paper tape back to the
'60s. I was in the Air Force from 1960-1964 as an electronics technician
maintaining cryptographic equipment, some of which was used with teletype
equipment. Teletypes used a 5-bit code called Baudot code.
For those of you who have heard the term baud before, it represented a single
character in the Baudot code. There was a specific code that shifted between
letters and numbers/figures modes, so that there could be more than 32 values
represented.
Messages could be punched onto a paper tape from a keyboard and then later
transmitted through a tape reader into a communications link. Or, on the
receiving end, a message could either be printed by a teletype or punched into
a paper tape for further transmission or later printing.
The technology was eventually used with early computers, as you are hearing
here.
Mike Myers
Mentor Services Corporation
On 01/13/2017 03:35 PM, David W Noon wrote:
> On Fri, 13 Jan 2017 14:21:58 -0600, Tom Marchant
> ([email protected]) wrote about "Paper
> tape (was Re: Hidden Figures)" (in
> <[email protected]>):
>
>> On Fri, 13 Jan 2017 13:56:57 -0600, Mike Schwab wrote:
>>
>>> https://en.wikipedia.org/wiki/Punched_tape
>>> About 1974-75, I lived with my dad, manager of a Kroger store. At
>>> night he would insert various strips of punch film into a reader to
>>> report the store's daily transactions.
>> Well into the 1970's almost every mainframe shop used paper tape.
>>
>> What was it used for?
> In the mid 1970s I was working for a multi-national chemical company
> in Melbourne, Australia. We had 2 paper tape readers and 1 paper tape
> punch. They were used mostly for threatening young programmers who
> spoke derisively about punched cards. ... :-)
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