Random Access Memory: Difference between revisions

But most of these technologies were not terribly practical; they were expensive, slow and (especially in the case of mercury delay lines) environmentally dangerous. Dr. An Wang (then of IBM) proposed a solution which took the industry by storm -- ''magnetic core memory''.

 

 

Core memory consisted of thousands of tiny (1–2 mm wide) donut-shaped magnetic cores, set on a grid of metal wires. By manipulating the voltages put on these wires, the state of any individual core could be read or written. Since there were no moving parts, as with a delay line or a drum, access time was much quicker. Core memory was also substantially denser than either delay-line or CRT memory, and used less power as well. It also held its content when the power was off, which was widely used at the time.