Discovered in 1930, these crystals have the formula M 3 AB where M represents a magnetic element, Mn, Ni, or Fe; A represents a transition or main group element, Ga, Cu, Sn, and Zn; and B represents N, C, or B . These materials demonstrated superconductivity, giant magnetoresistance, and other unusual properties.
22.
It was a serial decimal machine with an, 10, 000-word magnetic drum memory . ( As CALDIC's decimal words were 10 digits each, the magnetic memory could store about 400, 000 bits . ) It contained 1, 300 vacuum tubes, 1, 000 crystal diodes, 100 magnetic elements ( for the recording heads ), and 12 relays ( in the power supply ).
