The first hard drive: how IBM 350 started the era of storage devices
On September 13, 1956, IBM shipped the first commercial hard disk drive — the IBM 350, designed for the 305 RAMAC computer. The device weighed over a ton and stored 5 million characters, recorded as six data bits, one parity bit, and one space bit per character.
The name RAMAC stood for “Random Access Method of Accounting and Control”—a method of random access for accounting and management. The key innovation was that data could be read in random order for the first time, rather than sequentially as with magnetic tape or punch cards.
The IBM 350 storage unit consisted of fifty disks with a diameter of 24 inches (about 61 cm). Two independent moving heads could select the required disk and track, providing data access in an average of 600 milliseconds.
The IBM 305 RAMAC system was one of the last vacuum tube computers from IBM. The entire installation including processor, printer and control console occupied a room about 9 by 15 meters. The company leased the system for $3,200 per month — in today’s money about $36.7 thousand.
The first hard drive laid the foundation for an entire field. According to Wikipedia, more than 1000 RAMAC systems were produced between 1956 and 1961, and the IBM 350 drive later gave way to more advanced models. But it was this drive that defined the development path of data storage devices for decades.
Today, when everyone has a smartphone with hundreds of gigabytes of memory in their pocket, it is hard to imagine that once storing a couple of songs required a machine weighing as much as a passenger car. However, it was with that bulky machine that the era that led to laptops, data centers and cloud services began.
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Primary source: en.wikipedia.org ↗