A Quick Refresher on How Computer Memory Works

Illustration for article titled A Quick Refresher on How Computer Memory Works

RAM, DRAM, SRAM, SSD, HDD. The language of computer memory, like most other components of computers and smartphones, is a collection of alphabet soup. So it can be difficult to wrap your brain around what exactly those collection of letters mean, and more importantly, what the hell they do.

Thankfully, this TED-Ed video breaks down the surprisingly human-like properties of computer RAM, or random access memory. Never knew the difference between DRAM and SRAM was? Confused why you should care if your new laptop uses solid-state drives instead of other out-of-date storage tech? This five-minute video explains it all.


This tutorial won’t exactly make you a professor on the subject. For example, it doesn’t even attempt to discuss quantum computing. But at least the next time you look at a spec sheet you won’t go completely cross-eyed.



Nice. Fun fact: some of the earliest computers used columns of mercury as RAM. Acoustic waves in the mercury acted as a delay line; you just waited for the data you wanted to go by.

Later computers used CRT tubes as storage, by charging and then reading tiny dots on the CRT screen.

Magnetic core memory was invented by Jay Forrester of MIT as part of the Whirlwind computer, the prototype for the AN/FSQ-7 that was the heart of the SAGE air defense system in the ‘50s. Whirlwind was one of the first truly modern computers. The process for making core memory planes was never automated; they were always made by hand. Women literally wove them; it was called LOL memory for Little Old Lady.

This coke-machine size cabinet held 64K of memory.