IBM 305 RAMAC: The Grandaddy of Modern Hard Drives

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The IBM 305 RAMAC, which debuted in 1956, was the first computer with a hard drive. It was 16 square feet, weighed over a ton, and had to be transported by plane. But it sure as Hell beat punch cards.

We often complain about legacy features holding back new technologies. For the computers of the early 1950s, punch cards were a hundred-year old legacy feature. Though they were easily destroyed and largely inefficient, they remained the predominant medium for data storage throuhgout the first half of the 20th century. Until IBM rolled out the 305 RAMAC.


It was the first commercial computer to use a moving head hard disk drive, storing five million characters of accounting data, the equivalent of 64,000 punch cards, on 50 24" magnetic disks. To put it in today's terms, the colossal machine held about 5MB of data. Its magnetic disks were accessed by two arms, controlled by vacuum-tubes, that were noisily protected by compressed air.

But still, for companies, the advantages were obvious. The 305 RAMAC—the name stands for Random Access Method of Accounting and Control—could deal with a variety of input sources, including punch cards, and could store and access unprecedented amounts of data with incredible speed. Perhaps more importantly, it was the first computer to offer random access to data, where previous storage tapes had to be run from start to finish to find the required piece of information. Compare the effort it takes to pinpoint a moment on a cassette tape to finding that same moment on a CD. Now think of that improvement in terms of the data accessed by every large corporation or governmental agency in the country. Yeah, the 305 RAMAC was a big deal.


Here's how IBM pitched the computer in 1956:

By the time production ended, in 1961, IBM had manufactured over 1000 305 RAMACs, which had been leased to companies for $3,200 a month. But for those companies, it was worth it—the amount of data they could store and the speed with which they could access it was becoming increasingly important to their bottom lines. And it was their investments in the 1950s that pushed the development of hard drives like those found in the 305 RAMAC, shrinking them to the ones we use in our gadgets today. [Wikipedia and Newsweek]


Memory [Forever] is our week-long consideration of what it really means when our memories, encoded in bits, flow in a million directions, and might truly live forever.