[NetBehaviour] The Hard Drive Turns 50.

marc marc.garrett at furtherfield.org
Fri Sep 15 12:26:58 CEST 2006

The Hard Drive Turns 50.

Melissa J. Perenson, PC World.

Today, the hard drive is found everywhere--from the PCs we use daily to 
MP3 players and memory keys so small you can toss them in your pocket 
and forget you're carrying around a hard drive. But when the hard drive 
was first introduced on September 13, 1956, it required a humongous 
housing and 50 24-inch platters to store 1/2400 as much data as can be 
fit on today's largest capacity 1-inch hard drives.

Back then, the small team at IBM's San Jose-based lab was seeking a way 
to replace tape with a storage mechanism that allowed for more-efficient 
random access to data. The question was, how to bring random-access 
storage to business computing?

Enter the RAMAC, 1956

IBM's answer to this quandary was the Random Access Method of Accounting 
and Control, dubbed the RAMAC for expediency. The device's name is a 
direct reflection of the need for such capabilities in the enterprise. 
Led by project leader Rey Johnson, IBM's San Jose lab brought the RAMAC 
305 to market.

Recalls Al Shugart, who worked as a field engineer at IBM before joining 
the RAMAC project and went on to later found Seagate Technology: "They 
were starting from scratch in the lab. The RAMAC was not just a disk 
drive, it was a whole system. Nobody had made disk drives before."

The approach IBM's engineers came up with represented a clean approach 
to random data access, notes Shugart: "The concept of the whole disk 
drive was random access." To achieve random access, the device would 
have to move its read/write heads around to different data tracks. "The 
easiest way to do that," he says, "was a stack of disks."

The integrated RAMAC was about two refrigerators in width and not quite 
as tall, and it literally weighed a ton. Its 50 24-inch platters were in 
a stack inside the unit, in an assembly that spun at 1200 revolutions 
per minute. The unit used two magnetic recording heads. The RAMAC could 
hold 5MB--about the storage that today is needed for one 5-minute MP3 
encoded at 128 kilobits per second.


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