noun
magnetic drum storage
A historical rotating magnetic storage device used as main memory in early computers; now obsolete in modern systems.
1950年代のコンピュータは磁気ドラム記憶装置を主記憶として使っていた。
Computers in the 1950s used magnetic drum storage as main memory.
Compound of 磁気 (magnetic), ドラム (drum), and 記憶装置 (storage device). The term directly describes the technology.