> bar fixed in place that spans entire radius of the writable surface, with an addressable strip of r/w heads that runs the length of it. That was called a fix

> bar fixed in place that spans entire radius of the writable surface, with an addressable strip of r/w heads that runs the length of it. That was called a fixed-head disk. They got rid of seek latency (still had rotational latency) and so there was a market niche for them as (e.g.) swap devices, but they had lower data density than moving-head disks did, so they went out of style. It looks like they are so obscure today that there's no wikipedia article, but here's an article from some other wiki: https://gunkies.org/wiki/Fixed-head_disk https://gunkies.org/wiki/Fixed-head_disk They are briefly mentioned in the general Wikipedia article on hard disk drives. There was also "drum memory" where there was a head per track on a cylindrical recording surface. Those seem to have dried up even earlier: https://en.wikipedia.org/wiki/Drum_memory https://en.wikipedia.org/wiki/Drum_memory Here's an info page about the DEC RS03 and RS04 from the 1970s. The RS04 weighed 120 pounds and had 1MB of capacity. https://www.storagenewsletter.com/2019/02/19/history-1974-dec-rs03-and-rs04-hdds/ https://www.storagenewsletter.com/2019/02/19/history-1974-de...