Keypunch

Hole punch cards and keypunch, English Key Punch or Punch Card, were used to create punch cards.

Punch cards were used

• For machine control as a carrier of the program code or
• As a storage medium for records in data processing - often for input data, but also for the storage of master data, address data, etc.

Lochzange

On September 23, 1884 filed

His first patent application on " Art of Compiling Statistics". He experimented in subsequent years with different hole card formats and arrangements. 1886 were used cards in the Baltimore " ... on the two long sides each with three rows of holes with a total of 192 hole positions " had. Was punched with a hole punch.

The first purely symbolic coding encountered in the course of time limits, the further development such as the Tabulating required numeric, alphanumeric coding later the hole card. This provided the

No. 1 is not, the Pantographenlocher

To 2, depending on the copy ( reflected on the then current state of the art ) but was clearly inefficient.

It refers essentially two devices with different Einsatzsprektrum.

Punch card punch

Data typists used the punch cards " stacks " created from existing documents or templates them - were to operate the device frequently - in its area of ​​data collection. The maps produced could be verified using the hole board tester. The data throughput was low, up to 10 characters / s

Hole punch cards were partly " keypunch " called; not to be confused with the apparatus described below.

The first electromechanical punch comes from IBM in 1923 with the type designation IBM 011 From 1964, are (IBM 029 see picture) programmable documented (by spanned on drum punch card, see picture) punch. This control aids for instance facilitated Tab characters, so either could only parts of the map (in addition, for example ) are punched.

Programmable Locher were until the mid 1980s in use. Hole punch cards were also used in the production planning of data centers ( to create JCL control card ) and by programmers who thus created punch cards that contained the source code of programs.

Keypunch

This was used for the automatic generation of hole cards and - in contrast to hole punch cards - driven by an upstream machine. As a peripheral device he initially served the tabulating machine, and later the computer as a monitor. Some models had a ring core memory, so that the buffered data, and relieved by the arithmetic unit. With a downstream read station were checked for correct perforation when required the punched cards. The flow rate was 100 to 400 map / minute.