When reading a punch card the first thing that you need to do is go down the rows and write down the numbers that are punched. The numbers 1 - 9 are known as digital portions. The top part of the card that does not have any numbers is called the zone portion of the card. These are numbered 12, 11, 10 (or 0). Each punched number represents a letter in the alphabet. For instance if you have a card that is punched 6 then you would need to go over six and down six in order to find out the letter, which in this case would be F. Sometimes there will be rows that are not in use. The punch cards make it possible to store 80 characters per punch card and they are used in order to store large amounts of data. Also it is possible for the punches to represent numbers. If the top of the card is punched and so is the digital portion than it is gareenteed to be a letter in the alphabet. However, if it is only punched in the bottom portion of the card then it will be a number.
This process takes patients and is not very easy the first time. I am still a little confused on every exact detail of how to read it but I believe I am very close. The website link below is where I found most of my information, which will help to better explain reading a chart.
http://www.colostate.edu/Services/ACNS/swmanuals/sasdoc/sashtml/lrcon/z0695224.htm
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