Early computers used vacuum tubes and relays as active components to process information. Later on, transistors replaced those as the main components used in computers development (transistorized gates, memmory etc).

But, on a certain period, before the use of semiconductor transistors, IBM was researching a parallel line of development that used a certain component X to achieve the same results as early transistors. Or so was the story that I heard a long time ago...

What I want to know/remember is the name of this component "X" ? I searched the whole net but could not find any reference for it.

  • \$\begingroup\$ Magnetic bubble logic springs to mind \$\endgroup\$ – JIm Dearden Jul 24 '15 at 18:13
  • \$\begingroup\$ Nope, it was something different. \$\endgroup\$ – Jorge Aldo Jul 24 '15 at 21:49
  • \$\begingroup\$ Well, i wont select a answer because none satisfied me. \$\endgroup\$ – Jorge Aldo Jul 26 '15 at 2:51
  • \$\begingroup\$ With so little information to go on its difficult to focus in on what you are asking for so I've concentrated on what IBM was developing in the period 1944 - 1953 (the critical valve-transistor era).In the 40's IBM were developing the ASCC (Automatic Sequence Controlled Calculator ) series starting with the Harvard Mark 1 (an electro-mechanical computer) in 1944. This was followed by the mark 2,3 and 4. The mark 4 was an all electronic device with magnetic core memory. The mark 3 included rotating magnetic drums, perhaps your mystery tech (see en.wikipedia.org/wiki/Drum_memory) \$\endgroup\$ – JIm Dearden Jul 26 '15 at 18:20
  • \$\begingroup\$ nope, it was something more revoluctionary than this. its a kind of would-be transistor working on different principle than semiconducting. \$\endgroup\$ – Jorge Aldo Jul 26 '15 at 18:52

Are you maybe thinking about magnetic logic? Possibly the magnetic amplifier?


  • 1
    \$\begingroup\$ One commercially successful magnetic computer was the Elliot 803 - using magnetic devices for logic, but transistors (driving them) for gain. en.wikipedia.org/wiki/Elliott_803 I don't know of any comparable IBM development. \$\endgroup\$ – Brian Drummond Jul 24 '15 at 10:34

Before CMOS came TTL (Transistor/Transistor Logic).

Before TTL came RTL (Resistor/Transistor Logic)

Before RTL came DL (Diode Logic)

Those were logic families. Computer memory used other technologies.

There are, and were, other ideas (quantum as well as magnetic), but those are the ones that were used to build computers. The IBM 608 was Diode Logic hardware.


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