We use a key punch (Fig. 5) to punch original information into blank cards. In the key punch there is one card channel; it has one entrance, one station, and one exit. At the card station, there are 12 _punching dies_, one for each position in the card column, and each card column is presented one by one for punching. The numeric _keyboard_ (Fig. 6) for the key punch has 14 keys: One key for each of the punches 0 to 9, 11, and 12, A _space key_, which allows a column of the punch card to go by with no punch in it, A _release key_, which ejects the card and feeds another card. [Illustration: FIG. 5. Key punch.] [Illustration: FIG. 6. Keyboard of key punch.] Of course, in using a key punch, we must punch the same kind of information in the same group of columns. For example, if these cards are to contain employees’ social security numbers, we must punch that number always in the same card columns, numbered, say, 15 to 23, or 70 to 78, etc. Verifier The verifier is really the same machine as the key punch, but it has dull punching dies moving gently instead of sharp ones moving with force. It turns on a red light and stops when there is no punched hole in the right spot to match with a pressed key. Sorter The sorter is a machine for sorting cards, one column at a time (Fig. 7). The sorter has a card channel that forks; it has one entrance, one station, and 13 exits. Each exit corresponds to: one of the 12 punch positions 0 to 9, 11, and 12; or _reject_, which applies when the column is nowhere punched. It has one card station where a brush reads a single column of the card. We can turn a handle and move the brush to any column. [Illustration: FIG. 7. Sorter.] Interpreter The interpreter takes in a card, reads its punches, prints on the card the marks indicated by the punches, and stacks the card. We call this process _interpreting_ the card, since it translates the punched holes into printed marks. The interpreter (Fig. 8) has one card channel, with one entrance, 2 card stations, and one exit. What the machine does at the second card station depends on what the machine reads at the first card station and on what we have told the machine by switches and plugboard wiring to do. [Illustration: FIG. 8. Interpreter.] Reproducer The reproducer or reproducing punch can: _Reproduce_, or copy the punches in one group of cards into another group of cards (in the same or different columns). _Compare_, or make sure that the punches in two groups of cards agree (and shine a red light if they do not). _Gang punch_, or copy the punches in a _master card_ into a group of _detail cards_. _Summary punch_, or copy totals or summaries obtained in the tabulator into blank cards in the reproducer. [Illustration: FIG. 9. Reproducer.]