Historical Computer Engineering - Punchcard
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Punchcard

Punch Cards — Format & Coding

Before there were any punch tapes there were punched cards. In general one card holds one command. In the beginning there were a lot of different formats for those cards. It was not until 1928 until a final format was set.
A standardized Hollerith–Card (named after their inventor Herman Hollerith) measures about 18.7 × 8.3 cm and is typically a rectangle peace of card.
The first cards used for the census in 1890 provided 240 possible positions for holes. Later versions used 45 columns with 12 positions each, which equals 45 signs at 12 bit.
1928 IBM registered a 80 column format with rectangular holes, which is the most common and still in use on some IBM machines. Those 80 columns as a maximal length for lines in emails, text files and terminal windows is a relict of that time.
At first only one hole was allowed per column, later an additional hole was allowed for capital letters, then a third for special characters. Finally up to six holes per column were allowed. With an EBCDIC-Code one card could hold up to 80 Byte of data.

Fortran–program

Sample program

Animation the Fortran–program–example:
Because of the little fragment of the original program, we made these premises:
M(0:10);       ZW(1:10);       ZR