Comprehensive Introduction - IBM 29 Instruction Manual

IBM 29 Card Punch, with Left-Zero Insertion
Comprehensive Introduction
• Zeros are inserted to the left of the first significant digit.
• Operator keys exact number without leading zeros.
• Only numeric information can be entered.
• Keying mistakes can be corrected.
The left-zero insertion feature permits the operator to
key in only the necessary significant digits in a numeric
field. The operator can then press the left-zero (or dash
key for a credit field), and the machine will punch the
field with the correct number of zeros in front of the
significant number. Only numeric information can be
entered into the left-zero field.
If a key is pressed that
results in punching a 12, 11, or 0 hole, plus numeric
information, only the numeric information will be
entered.
The left-zero feature reduces the total number of key
strokes necessary to punch a field. The operator does
not need to figure out the correct number of zeros to
insert in front of the number.
If an operator makes a
mistake in keying, the field can be cleared and the cor-
rect number can be keyed in without losing informa-
tion in the card.
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