IBM 350 Disk Storage Unit
The 350 Disk Storage System was a major component of the IBM 305 RAMAC (Random Access Method of Accounting and Control) system, which was introduced in September 1956. It consisted of 40 platters and a dual read/write head on a single arm that moved up and down the stack of magnetic disk platters. Those 40 platters stored a whopping (for the time) 5MB of data.
Return to Computer History Museum to highlight storage, from RAMAC to microdrives
Photo courtesy of IBM Archives.