Erik Stemme and Gunnar Stenudds created the carousel memory.[1] It was shown for the first time at a exhibition in Paris in 1958.[2]
Facit ECM 64 edit
The FACIT ECM 64 used another technique than a long tape. Instead 64 small rolls[3] with 9 meters,[3] 1.6 cm wide [3] tape on each roll, divided into 8 channels.[3] The tape speed is 5 m/s.[3] To read a specific roll the carousel were rotated such that the roll ended up at the bottom. A weight in the free end of the tape pulled it out and down inside a mechanism with a read- and write head. After this it was fast re-winded back. The average seek time was 2 seconds[3] and the storage space was 2560 kByte.[4] The control system were completely transistorized. Both the carousel and individual spools could be replaced.[1]
The magnetic tape used 5/8 inch (1.6 cm) wide, 0.05 mm thick Mylar 3M Co type 188.[3] The storage density is specified to 8 bits/mm[3] and the access head had the capability for simultaneous read- and write operation.[3] The power inlet requirement is 3-phase 380 volt 50 Hz and needed 300 W in standby and 750 W when active. Signaling for data used 8 parallel -20 V to 0 V 5 µs pulses.[3]
Peak transfer speed was 182 044 bits/s[4][3] using 8-parallell lines[3] and thus 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 edit
- Karlqvist gap, calculation of magnetic field in ferromagnetic layer
- Exatron Stringy Floppy, 1978 endless tape drive 64 kB
- ZX Microdrive, 1983 endless tape drive 85 - 100 kB
- Rotronics Wafadrive, 1984 endless tape drive 128 kB
Further reading edit
- tekniskamuseet.se: Startsida > Veta mer > Kommunikation & IT > Datorn > Arkivmaterial (Swedish, 2009-12-02)
- tekniskamuseet.se: TPU 610301 FACIT ECM 64 Karusellminne, Preliminär teknisk beskrivning (Swedish 1961, 2012-06-15, 2936 kB)
- tekniskamuseet.se: Facit Electronic presenterar FACIT ECM 64 Magnetbandsminne av karuselltyp med direkt access (Swedish 1963, 2012-06-15, 2581 kB)
- tekniskamuseet.se: Facit electronics AB TPU 610301 (Swedish, 2012-06-15, 1702 kB)
- tekniskamuseet.se: Facit electronics AB TPU 610301 Facit ECM 64 Karusellminne, Preliminär teknisk beskrivning (Swedish, 2012-06-15, 3858 kB)
- tekniskamuseet.se: Facit electronics AB, Photographs Facit ECM 64 (Swedish, 2012-06-15, 2618 kB)
- utah.edu: Nordisk tidskrift for informationsbehandling Volume 2, Number 1, March, 1962
- springer.com: Applications to the magnetic tape storage unit, facit ECM64 (the Carousel Memory), BIT Numerical Mathematics, March 1962, Volume 2, Issue 1, pp 16-20 (article)
References edit
- ^ a b Pär Rittsel (2002), Valsen inledde skivans historia [The roll initiated the disc history] (in Swedish), International Data Group (published 2010-09-11), retrieved 2016-03-22,
Även om datorerna blev få så blev Erik Stemmes och Gunnar Stenudds karusellminne, stans och läsare för hålremsor stora
(HTML 26 kB) - ^ Magnetband till karusellminne, Föremål [Magnetic tape for carousel memory, Object] (in Swedish), Kringla, Riksantikvarieämbetet, retrieved 2016-03-22,
Karusellminnet Facit ECM 64 visades första gången på en utställning i Paris 1958. Serietillverkades åren 1959-1964.
(HTML 67 kB) - ^ a b c d e f g h i j k l FACIT electronics AB (1961), TPU 610301 FACIT ECM 64 Karusellminne, Preliminär teknisk beskrivning [TPU 610301 FACIT ECM 64 Carousel memory, preliminary technical description] (PDF) (in Swedish), Swedish National Museum of Science and Technology (published 2012-06-15), pp. 3- (PDF 2936 kB)
- ^ a b FACIT electronics AB (1963), Facit Electronic presenterar FACIT ECM 64 Magnetbandsminne av karuselltyp med direkt access [Facit Electronics presents FACIT ECM 64 Magnetic tape memory of carousel type with direct access] (PDF) (in Swedish), Swedish National Museum of Science and Technology (published 2012-06-15) (PDF 2581 kB)
- ^ Göran Arvidsson (2002), FACIT i den tidiga dataåldern [FACIT in the early computer age] (PDF) (in Swedish) (published 2015-08-23), p. 3 (PDF 682 kB)