The dynamic RAM cell, i.e. a memory cell that stores information as charge on a capacitor, which must be refreshed periodically, has been invented by John V. At

The dynamic RAM cell, i.e. a memory cell that stores information as charge on a capacitor, which must be refreshed periodically, has been invented by John V. Atanasoff, no later than 1940 (at the Iowa State College), when it was described in “Computing Machine for the Solution of Large Systems of Linear Algebraic Equations”. After the DRAM made with discrete capacitors that was used in the Atanasoff-Berry electronic computer, the next invention was the Williams–Kilburn tube, invented in 1946 at the University of Manchester, which replaced the array of discrete capacitors with a cathode-ray tube. Such memories with CRT's have replaced the slower memories with delay lines, before being replaced themselves by the memories with magnetic cores. For example, the first commercial IBM electronic computers, IBM 701 (1952) and IBM 702 (1953), had such DRAM made with CRT's, while their successors from 1954 had static non-volatile memories made with magnetic cores. After more than a decade of neglect, the DRAM has been revived in the form of MOS integrated circuits, after the inventions by Toshiba and Dennard. Neither of them has invented DRAM, but they have just invented new methods of implementing the capacitors required by a DRAM, by using transistors. According to Wikipedia, Dennard has invented at IBM the one transistor memory cell, which has been used in later DRAM products, not in the first generation launched by Intel in 1970 and followed by similar products from other US companies and from other countries, like the Soviet Union IC discussed in the parent article. The first Intel DRAM was based on a less efficient 3-transistor memory cell invented at Honeywell. The earlier Toshiba invention was for the first kind of DRAM using bipolar transistors, which was used only in their calculators, while the later Dennard invention was for the improved MOS memory cell, from which all later DRAM cells were derived.