October 12, 2006

Happy Birthday!

The hard disk drive turned 50 last September. From the IT Jungle:
The Disk Drive at 50: Still Spinning
This month marks the 50th anniversary of the announcement of an innovative storage technology that IBM created and launched for its early computers--a device that predates its vaunted System/360 mainframe by eight and a half years. Back in September 1956, it was just called the IBM 305 RAMAC, and it wasn't a disk drive so much as computing system attached to a giant disk drive. That device, the great-great-granddaddy of the spinning disk in your computer and those in use at your company, is arguably one of the most persistent pieces of technology ever created.

Early phonographs created by Thomas Edison stored data on a rotating drum. Edison made scratches in the drum to record sound, and then rotated the drum to recreate the vibrations that in turn caused a horn to vibrate with the sound that was recorded--with a much lower fidelity, to be sure. Eventually, records were turned into platters and mass-produced, creating a music-listening industry where once there had been a sheet music business and a world of half-rate musicians--our relatives and friends.

By the late 1950s, information had been encoded on punch cards for decades and had more recently be put on magnetic tape. The genius of the RAMAC drive was its speed. But storing data on the top and bottom of metal disks using magnetic material is not an IBM invention--in fact, it was created in 1952 by an engineer named Jacob Rabinow, who worked at the U.S. Army's Ballistic Research Laboratory on its Aberdeen, Maryland, proving grounds. IBM's researchers initially chose a drum for RAMAC instead of a disk platter (which was easier to manufacture) because it was stiffer and therefore it was easier to maintain a consistent space between the drum and the head that read data off the drum or magnetically encoded it on the drum. But the RAMAC 305 actually consisted of 50 metal platters, spinning at 1,200 RPM and a recording density of about 100 bits per inch. RAMAC was capable of storing between 5 million and 20 million "words" of data. Yes, this predates bits and bytes as we know them.
Storage capacity of about half a meg and as large as a washing machine. The disks could become unbalanced and when that happened, this 800 pound machine would start rocking back and forth, sometimes walking around the datacenter crashing into stuff. Talk about good old days indeed! Posted by DaveH at October 12, 2006 10:09 PM