Hard Disk's 50th Anniversary

Yes, there were hard disks for computers even before I started using them. Yesterday's Wall Street Journal had a story by Lee Gomes on the 50th anniversary of the hard-disk drive. Worth reading in full, but here are some excerpts:

[The hard drive] is the storage device that makes possible not only PCs, but also iPods, TiVos and other consumer technology must-haves.

The first disk drive, called the RAMAC, was created by International Business Machines Corp. engineers in San Jose, Calif., in 1956...

The disks on it were 24 inches in diameter. The whole unit weighed over a ton, and had to be delivered on forklifts and loaded on to large cargo bays of airplanes. You had only five megabytes of storage. That's about five minutes worth of MP3 music...

It was four or five years between the first RAMAC and the next one, and there was a significant jump in storage capacity, which has been steady since then. For the first 35 years, storage capacity increased about 30% a year. Those annual increases got as high as 100% between 1998 and 2002. Today, they are running around 30% to 40% a year...

The RAMAC stored 2,000 bits per square inch. In disk drives today, the figure is as high as 135 billion bits per square inch. That's almost a 70-million-fold increase. And in the next five years, we will ship more disk drives than we shipped in the first 50 years...

I remember being told by Tom Steel that the machine room at the Equitable Life Insurance company was located directly below the office of a vice president, who was definitely not amused that his office floor had to be taken up and a crane brought in whenever they had to change the actual RAMAC disk. (Disk reliability has improved enormously since then.)

My first encounter with hard disks was in 1965. The Loma Linda University Scientific Computation Facility had an IBM 1620 Data Processing System with two 1311 Disk Storage Drives. Each removable 1316 Disk Pack consisted of six 14-inch diameter disks, weighed 10 pounds, and could store 2 million characters (2MB, the equivalent of 25,000 punched cards). This was a revolutionary advance over storing all the system software, application programs, and datasets on cards and manually placing them in the card reader (or removing them from the card punch) as needed. For me, it was much more important than the speed and memory advantages that the 1620 had over the Bendix G-15D.

Edited on 9/14/2006 to add: Other interesting sites

• PC World article by Melissa J. Perenson
• Washington Post timeline by Rex Farrance
• Magnetic Disk Heritage Center