Fast, reliable computers depend on fast, reliable main memory to hold actively running programs and data.
Recognizing the need was relatively straightforward. Meeting the need, not so much. Designers of the first computers struggled to find a memory technology that combined speed, dependability, and affordability. In its pursuit they were creative, persistent, sometimes frustrated…and eventually, successful.
One Bit at a Time
Early memory technologies, such as delay lines and magnetic drums, were serial. To read or write data, the computer waited for information that circulated in a loop to arrive at a place where it could be read or written.
Random access memory (RAM) eliminated the wait, enabling much faster operation.