Search results
Results from the WOW.Com Content Network
An IBM 80-column punched card of the type most widely used in the 20th century IBM 1442 card reader/punch for 80 column cards. A computer punched card reader or just computer card reader is a computer input device used to read computer programs in either source or executable form and data from punched cards.
This category contains articles about punched cards and card handling equipment, including card readers, card punches, and keypunches. Subcategories This category has the following 2 subcategories, out of 2 total.
A 12-row/80-column IBM punched card from the mid-twentieth century. A punched card (also punch card [1] or punched-card [2]) is a piece of card stock that stores digital data using punched holes. Punched cards were once common in data processing and the control of automated machines.
A single program deck, with individual subroutines marked. The markings show the effects of editing, as cards are replaced or reordered. Many early programming languages, including FORTRAN, COBOL and the various IBM assembler languages, used only the first 72 columns of a card – a tradition that traces back to the IBM 711 card reader used on the IBM 704/709/7090/7094 series (especially the ...
It is called an overpunch because the digit in that column has a 12-punch or an 11-punch above it to indicate the sign. The top three rows of the card are called zone punches , [ 3 ] and so numeric character data which may contain overpunches is called zoned decimal .
IBM 1442 [1] [2] is a combination IBM card reader and card punch. It reads and punches 80-column IBM-format punched cards [3] and is used on the IBM 1440, the IBM 1130, the IBM 1800 [4] and System/360 [5] and is an option on the IBM System/3. [6]
Columns on different punch cards vary from 5 to 12 punch positions. The method used to store data on punched cards is vendor specific. In general each column represents a single digit, letter or special character. Sequential card columns allocated for a specific use, such as names, addresses, multi-digit numbers, etc., are known as a field.
Numeric columns have one punch in rows 0-9, possibly a sign overpunch in rows 11-12, and can be sorted in a single pass through the sorter. Alphabetic columns have a zone punch in rows 12, 11, or 0 and a digit punch in one of the rows 1-9, and can be sorted by passing some or all of the cards through the sorter twice on that column.