Mom and IBM
My Mother and the IBM 604 Electronic Calculating Punch
In May 1954, my mother graduated from Hollins College (now Hollins University) with a bachelor's degree (A.B.) in mathematics and physics. She then went to work as a computer programmer for the National Advisory Committee for Aeronautics (NACA) which later became the National Aeronautics and Space Administration (NASA) the first of September, 1954. Although she was a civil servant who worked for Langley Research Center, her division was run by the International Business Machine Company (IBM). Her specialty was the IBM 604 Electronic Calculating Punch. The computer had 2 main components: the arithmetic unit and the card reader/punch. [Pictures and technical information about the IBM 604 can be found at websites for Columbia University Academic Information Systems and The University of Amsterdam Computer Museum.]
|IBM 604 with arithmetic unit on left and card reader on right. Note panel on left side of arithmetic unit and punchboard panel on front of card reader.
photo from http://www.columbia.edu/acis/history/604.html
|IBM 604 with panels open.
|Vacuum tubes from inside arithmetic unit of IBM 604.
The arithmetic unit was a large unit (about a foot taller than she was at 5'8") filled with vacuum tubes. There was a window on the side through which she could look at a series of lights (each light represented one of the vacuum tubes in the machine) and check the binary programming. Except for looking through the read-out window, she never touched the arithmetic unit, though she saw the inside of it whenever the "guys" (i.e., what today would be called technical support) opened it up to work on it.
The card reader/punch was tall enough to stand at comfortably. There was a place where you dropped in a stack of punchcards that held the data. On the front was a removable panel that she called the plugboard.
She could take this piece to her desk to do the actual programming. She would have first worked out the formula and converted it to binary. Then once that was done, she could connect the wires from the digital input to the output section. The plugboard had holes and the wires had metal ends on them that snapped into place. The wires were color-coded by length. It was similar to a switchboard in its ease of use compared to earlier plugboards. There were 80 columns of holes on a punchcard. These were all pre-identified in the wind tunnel. Each wire represented one of those holes. The first number that you wanted to use, you read into the first storage unit by plugging one wire for every digit which you wired from there into the calculating unit. Then you would read in another number using the same process. The next step would be to tell it what calculation to perform with those two numbers and where to put the answer.
The Langley facility consisted of a large number of wind tunnels in various sizes and shapes and functions. These were operated by engineers who would test various airplane parts to see if the design performed as predicted. In the wind tunnel they would put sensors on the wing or flap or whatever they were testing. The engineers would change the wind factors to test the various strengths of those parts in different wind conditions. Those sensors would output large quantities of data that was then processed by hand on Friden calculators, mostly by female mathematicians (the engineers were all men).
photo from http://www.hpmuseum.org/big/friden.jpg
[Note: Langley personnel came to Hollins recruiting math majors. They told her at the time that they preferred female mathematicians to male mathematicians because they were better suited to the job.] IBM had recently gained access to doing this kind of work to demonstrate their equipment and its efficiency over the traditional methods in place at that time. Part of my mother's job in that department was to sell their methods and their services to the engineers. An engineer would come to her office and tell her what he needed. It was her job to show him what she could do and convince him to let her do it. Then she would sit down with his material and plan the series of program steps required to produce the data that he needed. It often too many passes through the machine to reach the end result because the 604 could only process 64 program steps in one pass, where one step could be to read in input, perform a calculation, or read out output. The only calculations it could do were addition, subtraction, multiplication, and division. It took 64 program steps just to do one square root .
There were eight programmers, two supervisors and about a dozen keypunch operators employed in the center. They worked two shifts, either 8am to 4pm or 3:30pm to 11:30pm (a day shift and swing shift but no graveyard shift). Everyone was divided into four teams and each team had three weeks of day and one week of night shifts. Because the machines were so expensive and there were such massive amounts of data, it was important to keep the machines running as much as possible. During the night shift, she could do her own programming but couldn't meet with the engineers so sometimes she helped load the punchcards into the machines. Her training to be a programmer consisted of the manual and the IBM supervisors who walked her through the process and followed up with help as needed.
The center had three 604's and 4-5 402's (the printer) and a CPC (Card-Programmed Electronic Calculator) which was a combination of the 604, the printer, and external memory. Though the CPC was considered more complete, it was a noisier system than the individual machines. She was assigned to the 604. Before she left in September of 1955 to get married, Langley received a new IBM 650. It was in operation before she left but because she was leaving, she never took the training on it. The big advances made by the 650 over the 604 included the fact that it had magnetic drum storage that would allow for more complex operations because the 604 had no "storage". The storage units in the 604 could only read in and read out in the same operation. The 650 could "hold" information to be processed in the next step.
My mother lived in an apartment in the town of Hampton, Virginia. She started out rooming with three other programmers from her office. Two of them moved out (one got married). She and the remaining roommate moved into a smaller apartment where she lived until leaving Langley a year later. She had a car and drove to work (most people did...there was no public transportation on to the base as far as she remembers). They were totally divorced from the Air Force. They were not eligible to use the military facilities (commissary, PX, officers' club, etc.). However, since her father was in the Air Force and Langley was TAC (Tactical Air Command) headquarters, he came on business from time to time and he took her to those facilities on base.