REFLECTIONS ON EARLY COMPUTERS

Chapter 1

THERE WAS LIFE BEFORE COMPUTERS


1. The Realization

One day, in the late 1980's, I had just taken an assignment about 1,600 miles away from home. For my initial journey, I packed up as much as I could take on the airplane. I expected to frequently commute back and forth for several months, so my first priority items did not include a soft copy of my resume.

Upon arriving at my new desk, the first thing for which I was asked was an updated resume. All I had with me was a hard copy of my resume, and I did not want to re-key the whole thing into a new computer file. Note that we did not have scanners in the 1980's. My resume required much changing. I had additional employment.

While coping with the quandary caused by this problem, I remembered how I did my first resume--before I had been exposed to computers. I had used an ancient practice known as cut-and-paste. You just type up the new sections of your resume, make cut-outs of old parts to bring over to the new resume, and paste everything together.

Thus using this ancient practice -- that will some day be a lost art -- I was able to create what I needed.

This incident proved that there was life before computers.


2. The Computer-less Environment

In the 1940's and early 1950's we had devices know as EAM Machines, which stood for Electric Accounting Machines. These machines were primarily made by IBM and utilized an archaic input form know as the Punch Card , and an archaic programming device know as the Plug Board .

Only very fortunate people had this "advanced" technology at their disposal. Others, without punch cards and plug boards, had mechanical calculators known by such names as Frieden, Monroe, and Olivetti. Huge rooms full of clerks spent their days banging numbers into these machines for accounting, billing, inventory, and other uses. Other people had mechanical typewriters which typed directly onto paper, and each error had to be manually erased and corrected. But reading about these archaic tasks might be too gruesome a task for the young minds of today. Consequently, I will begin my reflections with the people who were considered the more fortunate of the time -- The Punch Card and Plug Board set, whom I will call the EAM People.

The EAM People had three primary types of machines, (1) the key punch machines on which they punched holes in the punch cards, (2) card sorters, and (3) the accounting machines that interpreted the programs wired into plug boards.

2a. The Punch Card

If you have never seen an IBM punch card, it was a piece of cardboard, about the thickness of a 3 x 5 index card and cut into a rectangle about 3" by 7 1/2". One corner of the card had an angle cut in it so you could identify a card that was not correctly oriented. Each card had 80 columns and 12 rows. You could punch 80 alpha-numeric characters of data into each card by placing a distinct pattern of rectangular punches in each column. There was a strip on top of each column on which you could print the information on the card. Each row on the card had a name: The top row was called the 12-row, the row below that was called the 11-row and the ten rows below that were called 0-row, 1-row, ... , 9-row. Data were punched into the cards as follows: An numeral was identified by a single punch in one of the ten bottom rows. The top three rows were known as zones. An alphabetic character was identified by two punches, one in a zone, and one in one of the nine bottom rows.

Figure 1 shows such a card as copied from a 1957 FORTRAN Manual. Note that this card was specially printed for entering FORTRAN source code. A generic card would be blank except for the matrix of the integers 0 through 9. There approached an infinite number of special formats for cards for every conceivable purpose. Figure 2 describes the codes punched into these cards.

ibm card
Figure 1 -- A Punch Card


Fig 2
Figure 2 -- Punch Card Codes

2b. The Card Sorter

These cards were sorted by mechanical sorters that could sort one column into one of 14 pockets, one pocket for a punch in each column, one pocket for no punch, and a reject pocket. Pockets could be turned off, so that you could sort only on the three zone punches, the ten numeric punches, or the nine non-zone punches. The special punches, shown in Figure 2, may have been added only for FORTRAN. It does not appear that they could have been sorted. A column could be sorted for numerics or alphabetics. Sorting would start at the right-most column to be sorted. If you were sorting numerics, you would run the cards through the sorter once for each column. For alphabetics, you sorted twice for each column, first on the non-zones and second on the zones. You had to remember to change the column and, for alphabetics, pockets between sort passes. Can you imagine sorting 10,000 cards on 45 columns and then messing up the 46th and having to start over? Sometimes you could recover. I am not sure how alphabetics and numerics in the same column were sorted. A zero would seem to collate between "R" and "S." I presume that when you sorted on the zone punch, everything without exactly two appropriate punches would go into the "reject" bin. This bin would sort out all of the numerals. The "reject" stack could be appropriately merged with the alphabetics for an alphanumeric sort.

Cards came in boxes of 2,000. Each box was about 2 feet long.

2c. The Accounting Machines

The accounting machines were mysterious devices that looked like large floor-standing printers. At one end was a card reader that read stacks of punch cards and at the other end was a set of tractor wheels and print bars that spewed continuous form paper. The brain of the machine was the plug board, which was the program. Plug boards were programmed by the gurus of the time. Most people had no idea how they worked, but they could direct the accumulation and printing of data from punch cards on to paper. These machines could also punch out additional cards, so that if you had a process that was more complicated than a spreadsheet summing operation, you could do it in more than one pass. Figure 3 is an example of an IBM plug board.

407 Board
Figure 3 -- An IBM 407 Plug Board


Accounting machines survived into the computer age, where they were used as the first line printers.

These machines could also punch cards which could subsequently have additional information punched on them. For example, it could punch out a time card with each employees name and other information. Later, additional information, such as hours worked, could be punched into the card, and card could be reprocessed. Remember, there was only 80 columns on the card. Consequently, the pre-punched data plus the additional data could not exceed 80 characters. The worst crime of the era was to fold, spindle or mutilate your time card. Printed on many cards of this era was the warning: "Do not Fold, Spindle or Mutilate this Card!"

Most card punches that were attached to accounting machines could not print the data that they punched into card. So another machine called a card printer was used. The sole purpose of this machine was to print one line of information on the top line of a punch card. This machine had a plug board that directed which columns of the card would be printed, and the orientation of the printing. The orientation was important because each print bar on this machine was wider than a column on the card. Only 60 characters of information could be printed.

2d. The Key Punch Machine

The key punch machine was the longest surviving member of the EAM era. These were typewriter-like devices that armies of key punch machine operators used to place information onto punch cards. The keyboard was much like a computer keyboard, with a typewriter layout and 10-key numeric layout. Some early key punch machines only had a numeric keypad.

Key punch machines were programmable. The program was written on -- guess what? -- a punch card. At the top center of each machine was a removable drum that had a circumference exactly the same as the length of a punch card, and a height exactly the same as the height of a punch card. A punch card was clamped onto this drum to direct the key punch. Punches in the drum card determined how to treat the corresponding column of the cards being punched. A punch in the drum card could be used to (1) pass over a column, (2) repeat the punched information from the prior card; pause for the operator (3) to key in an integer, (4) to key in an alphabetic, (5) to key in anything, (6) eject and go to the next card, or (7) or maybe something else I have forgotten about. At the same time that holes were punched into a card, key punch machines printed the data on the top line of each card. Each printed letter was directly over the corresponding punches. All 80 columns could be printed on each card.

The drum card could contain both a primary and an alternate program. One of the keys on the keyboard activated the alternate program. I wonder if this was the precursor to the "Alt" key we have on our keyboard, today. A card in a key punch machine could be at one of four stations: (1) the input hopper, (2) the punch head, (3) the read head, or (4) the output hopper. Each card went from the input hopper to the punch head. After being punched and ejected, the card stopped at the read head where information from the prior card could be repeated onto the next card. As each card was ejected from the punch head into the read head, the prior card went from the read head to the out hopper.

3. A Typical Application in this Environment

Given the technology of today, one might wonder how anything got done in this environment. This is a typical example of an exercise I went through at the beginning of each college term, to register for classes.

The gymnasium was full of desks with a college department representative occupying each desk. On each desk were boxes of punched cards. I stood in a long line of students. Other students stood in other long lines. What all the people in my line had in common was that all our last names began with "C." I held in my hand the list of classes for which I was to register. As I got to the head of the line, I gave my name, and someone handed me a punch card with my name and student number punched into the left columns of the card.

I then went to the desk for each department and each class on my list of classes. At each desk I was handed a punch card on which class and section information was punched into the right columns of a card.

When I collected all my cards, I went into another line. At the head of this line was a key punch. I handed my cards to the personnel at the key punch. The person put my cards into the in hopper of the keypunch -- Name card first-- class cards behind name card! The person pressed the "Alt" key and my name card glided past the punch head and stopped at the read head. My first class card was also ingested and paused under the punch head. The person then pressed another key on the key punch and the key punch began to punch my name and student number into each class card, each card from the previous.

That night, an army of clerks would fire up squadrons of card sorters and sort all those card by class, section, and student. Next these cards would be put into the printing machines and class lists would be available by the first class meeting.

The existing technology had risen to meet the challenge.

I am sure that the billing and other bean counting operations of the university used those cards over and over again until they were folded, spindled or mutilated.


4. Epilogue

The situation I have described existed in the late 1940's and early 1950's. In 1952, I took time out because I was need to attend to some business in Korea. When I returned in 1955, the technology was just getting ready to change.


1998 Paul M. Cohen. All rights reserved.
Permission is granted to print one complete copy for personal use. Such copy must contain this notice, but need not contain either the colored background or the simulated tractor holes. Permission must be obtained from the author for any distribution of this material by a means other than HTML link.


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