Signed overpunch
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A signed overpunch is a code used to store the sign of a number by changing the last digit. It was used in old punched card systems and was carried over to COBOL especially when using EBCDIC. Its purpose is to save a character that would otherwise be used by the sign digit.[1]
[edit] The codes
| Code | Digit | Sign |
|---|---|---|
| } | 0 | − |
| J | 1 | − |
| K | 2 | − |
| L | 3 | − |
| M | 4 | − |
| N | 5 | − |
| O | 6 | − |
| P | 7 | − |
| Q | 8 | − |
| R | 9 | − |
| { | 0 | + |
| A | 1 | + |
| B | 2 | + |
| C | 3 | + |
| D | 4 | + |
| E | 5 | + |
| F | 6 | + |
| G | 7 | + |
| H | 8 | + |
| I | 9 | + |
[edit] Examples
10} is -100
45A is 451
Decimal points are usually implied not explicit in the text. Using numbers with two decimal digits:
1000} is -100.00
