Magnetic Core Memory: Wang and Woo store data permanently
Now a days we trust computers to store more and more of our important records and information. However, before the 1950s no one would have even considered trusting a computer to store data-there simply was not the technology for long-term storage.
The first computers were not reliable because they stored data using such means as acoustic waves in mercury-filled tubes or complicated circuits of vacuum tubes. Then, in 1949, a new way of storing binary data was invented: “magnetic core memory.”
Computers store data as binary information where each bit of data is stored as a zero or a one (off or on). With core memory, metal cores are magnetized in one of two directions and this determines whether they store a zero or a one. These cores are threaded together by wire in a flat lattice formation and data is recorded or read by sending pulses of current through the wires to the cores.
The technology behind this core memory was created by the Shanghai-born U.S. physicists An Wang (1920-1990) and Way-Dong Woo. Its nature explains why computer memory is called “memory,” as magnetic cores like magnetic disks keep a record of their content even after the power supply is cut off. For this reason it is still sometimes used in specialized applications in military and space vehicles.