Processing a Punched Card File
To process a punched card file, your program must define the file by a DTFCD macro and a CDMOD (logic module generation) macro.
Punched card equipment normally performs only one function, for example reading cards or punching cards. Certain types of punched card equipment, so called card read punch machines, can perform both of these functions in a single path.
The IBM 3525 can also print on the cards of a file. Logically, however, data to be printed is a separate file; you must define this file in your program by a DTFPR macro and must also code a PRMOD macro. The section Programming for Associated Files provides hints for using the IBM 3525 to perform multiple functions on a file in one pass.
A card file on the IBM 3525 can be both read and punched in one run. To accomplish this, your program must define the file as combined. Coding considerations for a combined file are given under Updating a Record.
The IBM 3505 offers support for an additional kind of application: this card reader can be equipped with the optical mark reader feature. The feature allows up to 40 columns of marked data to be read. Hints for dealing with this data are given under Optical-Mark-Read and Read-Column-Eliminate Modes.