Folding machines

The IBM Type 77 pick-and-place machine, housed at the Museum, , UK .

Collating machines, RPM ( English collator ) - one of the types of devices used to process punch card arrays. The goal of the RPM was to combine two sets of cards while preserving their original order with the optional ability to remove a subset of the result set. Usually RPM consists of two 2 paths, including a punch card feeder, a control unit and 2 receiving pockets. Readable information is placed in four or five registers.

Most folding operations involved comparing two numbers. For example, when checking the sequence, the value from one card was compared with the value from the previous one in order to make sure that they are in the correct position.

Some advanced models, such as IBM Type 77 from 1937 to 1957, could perform a wider range of operations that allow storing and updating the data array in the correct alphanumeric order. The use of such machines made it possible to more efficiently carry out a number of economic tasks, such as extracting a card with debit account information and combining with a card with credit account data; replacement of cards with old data with their updated versions; selection of all cards for a certain period or according to some classifier.