How many rows and columns does a punchcard have?
Usually, 10 rows and 80 columns.Nope, 12 rows and 80 columns.The top two rows are zone rows, originally used for signs and control functions but now used for encoding alphabetic and special characters. The bottom ten rows are digit rows.Actually in EBCDIC, the top three and bottom two rows (called rows 12, 11, 0, 8, 9) are zone rows and the bottom ten rows (called 0, 1, 2, 3, 4, 5, 6, 7, 8, 9) are digit rows. If there are no punches in a column that column is blank, if there is only one punch in a digit row in a column that column is a digit, if there is one punch in row 12 or 11 or multiple punches in a column that column is an alphabetic or special character. In EBCDIC there can never be more than 6 punches in any column: all five zones punched and one punch in digits 1 through 7. Note that rows 0, 8, 9 are both zone and digit rows.