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词条 Carousel memory
释义

  1. Description

  2. See also

  3. References

  4. Further reading

{{notability|date=March 2016}}Carousel memory is a type of secondary storage for computers, which was created by Swedish computer engineers {{ill|Erik Stemme|sv}} and Gunnar Stenudd.[1] It was first shown at an exhibition in Paris in 1958.[2]

Description

The FACIT ECM 64, manufactured by Swedish company Facit AB, is a prototype of carousel memory. To avoid having a single, long magnetic tape, it instead has 64 small rolls of {{nowrap|9 meters}} each, with {{nowrap|1.6-cm}} wide tape on each roll, divided into {{nowrap|8 channels}} per roll.[3]{{rp|3}} The tape speed is {{nowrap|5 m/s}}.[3]{{rp|6}} To read a particular roll, the carousel rotates so the desired roll ends up at the bottom. A counterweight sits at the free end of the tape, and facilitates the roll in moving out and down into a mechanism with a read-and-write head. The tape is then rewound. The average seek time is {{nowrap|2 seconds}}[3]{{rp|11}} and the storage space is {{nowrap|2560 kilobytes}}.[4] The control system is operated by transistors. Both the carousel and individual spools are replicable.[1]

The magnetic tape is a 5/8-inch (1.6 cm) wide and 0.05 mm thick Mylar 3M Co type 188.[3]{{rp|11}}The storage density is specified to {{nowrap|8 bits/mm}},[3]{{rp|4}} and the access head is capable of simultaneous read/write operations.[3]{{rp|3}} The power requirement is 3-phase 380 volts 50 Hz, with {{nowrap|300 W}} when in standby and {{nowrap|750 W}} when active. Signaling for data uses {{nowrap|8 parallel}} -20 V to 0 V 5 µs pulses.[3]{{rp|13}}

Peak transfer speed is {{nowrap|182,044 bits/s}},[3][4] using 8-parallel lines[3]{{rp|13}} and thus {{nowrap|22,756 bits/s}} per line.

The first delivery of the Facit EDB 3 computer in 1958 (to ASEA in Västerås) used the carousel memory Facit ECM 64.[5]

See also

  • BESK, Sweden's first electronic computer, also developed by Erik Stemme
  • Exatron Stringy Floppy, 1978 endless tape drive
  • Karlqvist gap, calculation of magnetic field in ferromagnetic layer
  • Rotronics Wafadrive, 1984 endless tape drive
  • ZX Microdrive, 1983 endless tape drive

References

1. ^1 {{Citation|author=Pär Rittsel |accessdate=2016-03-22 |date=2002 |publication-date=2010-09-11 |title=Valsen inledde skivans historia |trans-title=The roll initiated the disc history |pages= |publisher=International Data Group |language=Swedish |url=http://www.idg.se/2.10186/1.217236/valsen-inledde-skivans-historia}}
2. ^{{Citation|author= |accessdate=2016-03-22 |date= |title=Magnetband till karusellminne, Föremål |trans-title=Magnetic tape for carousel memory, Object |pages= |publisher=Kringla, Riksantikvarieämbetet |language=Swedish |url=http://www.kringla.nu/kringla/objekt;jsessionid=9DD1B26C1E65FD73160B49DF921B73D5?referens=tekm/object/TM38278}}
3. ^1 2 3 4 5 6 7 8 {{Citation|title=TPU 610301 FACIT ECM 64 Karusellminne, Preliminär teknisk beskrivning|date=1961|url=http://www.tekniskamuseet.se/download/18.4d755928124885167d48000388/1339755649132/TM39138Bil3_+FacitECM64_+karusellminne_+prelteknisk+beskrivning.pdf|publication-date=2012-06-15|author=FACIT electronics AB|page=3|publisher=Swedish National Museum of Science and Technology|language=Swedish|trans-title=TPU 610301 FACIT ECM 64 Carousel memory, preliminary technical description|deadurl=yes|archiveurl=https://web.archive.org/web/20161013091854/http://www.tekniskamuseet.se/download/18.4d755928124885167d48000388/1339755649132/TM39138Bil3_%2BFacitECM64_%2Bkarusellminne_%2Bprelteknisk%2Bbeskrivning.pdf|archivedate=2016-10-13|df=}}
4. ^1 {{Citation |author=FACIT electronics AB |date=1963 |publication-date=2012-06-15 |title=Facit Electronic presenterar FACIT ECM 64 Magnetbandsminne av karuselltyp med direkt access |trans-title=Facit Electronics presents FACIT ECM 64 Magnetic tape memory of carousel type with direct access |pages= |url=http://www.tekniskamuseet.se/download/18.4d755928124885167d48000387/1339755649101/TM39138Bil1_FacitECM64_broschyr-+Magnetbandsminneavkaruselltypmeddirektaccess.pdf |publisher=Swedish National Museum of Science and Technology |language=Swedish |deadurl=yes |archiveurl=https://web.archive.org/web/20161013091952/http://www.tekniskamuseet.se/download/18.4d755928124885167d48000387/1339755649101/TM39138Bil1_FacitECM64_broschyr-%2BMagnetbandsminneavkaruselltypmeddirektaccess.pdf |archivedate=2016-10-13 |df= }}
5. ^{{Citation|author=Arvidsson, Göran |date=2002 |publication-date=2015-08-23 |title=FACIT i den tidiga dataåldern |trans-title=FACIT in the early computer age |pages=3 |url=http://www.brukskultur.se/uploadedFiles/81_data.pdf |publisher= |language=Swedish }}

Further reading

  • {{Citation|title=Applications to the magnetic tape storage unit, facit ECM64 (the Carousel Memory)|journal=BIT Numerical Mathematics | date=March 1962 | volume=2 | issue=1 | pages=16–20 |doi=10.1007/BF02024778 |last1=Karlqvist |first1=Olle }}
{{Magnetic tape data formats}}

2 : Information technology in Sweden|Swedish inventions
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