What are Punch Cards?

A punch card, also called a punch card , a Herman Hollerith card , or an IBM card , is a piece of cardboard that uses punched holes and non-punched holes to represent digital messages at known locations.

Punch card is also called punch card ,

In 1801, the Frenchman Joseph Marie Jaccar invented the pattern used to control the loom by punching cards. In the 1880s,

It works as follows: numbered 0 to 9 for a total of 10 lines; and an area for lines 11 and 12 (note that there is no line numbered 10).
The perforated combination of each column is used to represent a single character:

• Numbers are represented by punching a hole directly in lines 0 to 9.

• The space character does not need to be punched.

• The letter is represented by 2 holes: one hole is on the 11th, 12th, and 0th lines; the other hole is on the 1st to 9th lines. The alphabet is divided into nine letter zones ("zones"), and the letters of each zone are punched in order on the 1st to 9th rows. Each zone is punched in rows 11, 12, and 0, respectively. The first character in zone 3 is left unused.

• Some special characters use additional single-hole or double-hole representations.

• Most special characters (such as punctuation marks, etc.) are represented by 3 holes: line 8 is perforated; lines 0, 11, and 12 have 1 perforation; lines 1 to 7 have 1 perforation. Line 9 is left unused.

A total of 67 characters are represented.