Overpunch

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A way to express data in fields with positive, negative or unsigned numeric items without using +/-.

Overpunch Characters for Rightmost Digit in ASCII Coded Decimal Numbers are described below.

Digits  Pos     Neg     No Sign
0       {       }       0
1       A       J       1
2       B       K       2
3       C       L       3
4       D       M       4
5       E       N       5
6       F       O       6
7       G       P       7
8       H       Q       8
9       I       R       9

Signed decimal felds entered through punched cards are known as zone-signed fields. To represent a positive value, an overpunch is placed in the 12-zone above the rightmost digit of the field. To represent a negative value, an overpunch is placed in the 11-zone above the rightmost digit of the field. If no sign is desired, only the digits need be punched.

See HP COBOL II/XL Reference Manual Series 900 HP 3000 Computer Systems