The Zuse Z25 was a program-controlled electronic computer using

transistor upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...

s developed by Zuse KG in

Bad Hersfeld The festival and spa town of Bad Hersfeld (''Bad'' is "spa" in German; the Old High German name of the city was ''Herolfisfeld'') is the district seat of the Hersfeld-Rotenburg district in northeastern Hesse, Germany, roughly 50 km south ...

and put into production in 1963. The

word A word is a basic element of language that carries an objective or practical meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no consen ...

length was 18 bits, though it could also process double-word lengths for accuracy up to 10 decimal digits. The addressable space was 32768 words. The maximum size of the magnetic core memory was 16383 words. The programmable program memory had a maximum size of 4096 words.''Zuse KG: Einführung in die Arbeitsweise der Zentraleinheit des Datenverarbeitungssytems Zuse Z 25 (Ausgabe April 1963)''. For mass storage there was a

drum memory Drum memory was a magnetic data storage device invented by Gustav Tauschek in 1932 in Austria. Drums were widely used in the 1950s and into the 1960s as computer memory. For many early computers, drum memory formed the main working memory of ...

available as well as a

magnetic tape Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use mag ...

memory. The magnetic drum had a storage capacity of 17664 Z25 words. The transmission speed was 6900 words per second. The magnetic tape memory had a capacity of 1 million Z25 words and a transmission speed of approximately 33000 Z25 words per second.''Zuse Forum 10-1965, p. 34''. In- and output was through

punched tape Five- and eight-hole punched paper tape Paper tape reader on the Harwell computer with a small piece of five-hole tape connected in a circle – creating a physical program loop Punched tape or perforated paper tape is a form of data storage ...

and

punched card A punched card (also punch card or punched-card) is a piece of stiff paper that holds digital data represented by the presence or absence of holes in predefined positions. Punched cards were once common in data processing applications or to di ...

s; it was also possible to print to a

teleprinter A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point (telecommunications), point-to-point and point- ...

. The computer could carry out approximately 7100 arithmetic operations per second at a clock rate of 180 kHz. Several Z25s could be connected in a network. The Z25 could be used for the control and data acquisition of external devices through a program-interrupt system with up to 32 channels.

References

External links

* {{Konrad zuse computer Computer-related introductions in 1963 Konrad Zuse Transistorized computers Computers designed in Germany