IBM RAMAC

From Wikipedia, the free encyclopedia

RAMAC is an IBM trademark for mass storage products. Two different product families share the RAMAC name.

1 Original RAMAC
2 RAMAC redux
3 See also
4 Notes

[edit] Original RAMAC

RAMAC that is being restored by volunteers in the Computer History Museum in Mountain View, CA. source: Silicon Valley Sleuth blog.

When it was introduced in 1956 with the IBM 305 RAMAC computer system, the first computer to use disk storage, RAMAC was the first hard disk drive and originally an acronym for "Random Access Method of Accounting and Control". Its design was motivated by the need to replace the punch card tub file used by most businesses at the time. The RAMAC computer became obsolete in 1962 when the IBM 1400 series of computers became IBM's top selling mainframe.

The original 305 RAMAC computer system could be housed in a room of about 30' by 50' and had a disk storage unit measuring around 5' square. The first hard disk unit was shipped Sept. 13, 1956^[1]. The additional components of the computer were a card punch, a central processing unit, a power supply unit, an operator's console/card reader unit, and a printer. Functions were controlled by both machine language stored on a magnetic drum and a plug-board wired and placed in the unit. Each 350 RAMAC disk unit featured five megabytes of storage (5 million 7-bit characters, which works out to about 4.4 MB).

One of the features of its random access was a very large arm inside the disk storage unit that could locate information by its location number and the arm would go immediately to the information. This made it as quick as any computer in existence at that time.

In an interview^[2] published in the Wall Street Journal with Currie Munce, research vice president for Hitachi Global Storage Technologies, which acquired the IBM's storage business, said the entire RAMAC unit weighed over a ton and had to be move around with forklifts and delivered via large cargo airplanes. According to Munce, while the storage capacity of the drive could have been increased above five megabytes, the marketing department at IBM was against a larger capacity drive because they didn't know how to sell a product with more storage.

As of 2006, the Computer History Museum in Mountain View, California has a RAMAC disk drive which it is restoring.^[3]