Magnetic account computer

The articles medium data technology , midrange computer , magnetic account computer and magnetic account overlap thematically. Help me to better differentiate or merge the articles (→  instructions ) . To do this, take part in the relevant redundancy discussion . Please remove this module only after the redundancy has been completely processed and do not forget to include the relevant entry on the redundancy discussion page{{ Done | 1 = ~~~~}}to mark. Neutronstar2 ( discussion ) 11:38, Feb. 27, 2019 (CET)

Nixdorf System 820

Magnetic account computers (abbreviated: MKC ) were computer systems from medium-sized data technology that specialized in booking processes . They represented a fundamental new development of the booking machine based on an electronic computer and for the first time offered the possibility of electronic storage and processing of booking data. The storage medium was the magnetic account , essentially a conventional book sheet (also: account ), on the front / back of which the data and operating parameters of the respective machine were also stored on a magnetic strip .

The picture on the right shows a Nixdorf 820 without a magnetic account collection, a picture with the magnetic account collection can be found at Heribert Müller.

technology

A magnetic account computer consists of:

• Computer,
• Keyboard,
• Printing unit,
• Magnetic account card reader,
• Advertisement (only more modern models, luxury equipment).

A program adapted for the respective purpose ran on the computer, most of which was stored permanently in a toroidal core memory . The variable part of the software could be read in via the magnetic account card reader. The data for this were distributed on several magnetic account cards and had to be inserted one after the other. As this often took a long time, the machines were seldom turned off. The number of tracks and also the capacity of the magnetic account cards varied from manufacturer to manufacturer. The keyboard could be used to interact with the program and the booking data could be entered here. A wide variety of systems were used as the printing unit, the technology of which developed analogously to the typewriter. If type levers were initially used, later it was a ball head and finally a dot matrix printer . Some better devices had at least a single-line display. Usually, however, data was entered blindly.

The entire machine was usually built into a kind of table.

In the form of a complete system with hardware and software tied to a specific purpose , the magnetic account computer is a classic of medium data technology. During the heyday of magnetic account computers between 1960 and 1980, numerous system houses established themselves as service providers in this field.

use

The first machines of this kind used conventional book sheets (account cards), which were additionally provided with a magnetic strip on the back, in order to be able to save data in electronic form (a so-called "magnetic account card" ). The bookkeeper was left with the usual printed book sheet, from which the balance could also be read visually if necessary. The booking process remained largely identical to the purely mechanical booking. The magnetic account card was inserted into a slot and the data was read from the magnetic strip on the back. Stored data were typically the account number, the balance and the line number of the last posting. By reading the balance from the magnetic strip, there was no need to manually type the balance into the booking machine. In addition, the magnetic account computer could calculate directly with this data and automatically print the result on the magnetic account card. In order to position the book sheet on the next free, writable line, booking machines notched the account card at the edge in order to mark the lines that were already printed. The line number of the last booking was also electronically saved on magnetic account cards. The printing unit automatically went to the first free line in order to make the booking. When the booking process was completed, the data was updated with the new balance and the last line number and written back to the magnetic strip. The card was ejected through the slot.

meaning

The magnetic account computer accelerated the booking process, eliminated potential sources of error on the user level and enabled the electronic processing of booking data. There were no limits to the variety of possibilities. The first models came on the market at the end of the 1950s and were still very limited in terms of technology. With the increasing use of computers in larger companies from the mid-1970s, magnetic account computers were also repeatedly adapted and further integrated into the automation of business processes. The last models had interfaces to other computer systems and mass storage devices , but still produced a printed journal for accounting. The heavy use of computers from the mid-1970s onwards led to a revival of technology, which had already been declared dead, when the machines became affordable for medium- sized companies and became an interesting entry point into IT . When more and more personal computers were used from the end of the 1980s and thus became affordable for small businesses , the more than 30-year-old age of the MKC was over.

Country-specific features

In an international comparison, magnetic account computers have been in use mainly in Europe and especially in Germany and Austria . One reason is the special requirements of the tax authorities for the purpose of checking the accounting at any time. For example, while in the USA, due to the lack of corresponding restrictive laws, almost complete conversion to electronic bookkeeping with large EDP systems was made by the end of the 1950s, in Germany, printed accounts were still mandatory for auditing for a long time. For a long time, the magnetic account served de facto as an intermediary between traditional bookkeeping and modern electronic data processing.

Manufacturers and models

• anchor
• IBM , model 6400
• Kienzle , model 6000
• NCR , model 399
• Nixdorf , model 820
• Philips , model P 310 u. a.
• call
• Siemag , models Data 4000 / Data 8000
• Triumph-Adler , model TA 1000
• Robotron , models daro 1750 / daro 1840

literature

• Wilfried de Beauclair : Computing with machines: A pictorial history of computing technology . Springer Berlin Heidelberg, 2nd edition March 29, 2005, ISBN 3-5402-4179-5

Web links

• Philips P354 at computinghistory.org with an illustration of magnetic accounts

Individual evidence

1. ↑ Dipl. Phys. H. Müller: "Nixdorf 820 console with magnetic account attachment, two Forster branded punch card readers" In the "technikum29" museum
2. ↑ Only on the magnetic account are the numbers so beautifully red ( memento from September 10, 2014 in the Internet Archive ) - Computerwoche 27/1976
3. ↑ The magnetic account is far from dead ( Memento from September 10, 2014 in the Internet Archive ) - Computerwoche 5/1976
4. ↑ ibmcollectables
5. ↑ TheCoreMemory: NCR 399 with an illustration of a magnetic account card
6. ↑ Jürgen Gausemeier, Christoph Plass, Christoph Wenzelmann: Future- oriented corporate design: strategies, business processes and IT systems for the production of tomorrow , Verlag Carl Hanser Munich Vienna, 2009, p. 27 - ISBN 978-3-446-41055-8
7. ^ Leonhard Dingwerth: The history of the German typewriter factories: Volume 1 - Large and medium-sized manufacturers , Verlag Kunstgrafik Dingwerth, 2008, p. 160 - ISBN 978-3-921913-38-3