Brief Historical Summary, IBM 350 RAMAC Disk Drive
Announced September 4, 1956
The RAMAC disk drive stored 5 million characters (using a 6 bit character code plus an error detection parity bit and a space bit per character) in the form of 50,000 100-character sectors. The disks were 2 feet in diameter and the disk stack consisted of 50 magnetic disks for data storage in a stack 20 inches high. The maximum access time was 0.8 seconds to any record in the stack.
Why It's Important
The 350 RAMAC (RAMAC stands for Random Access Method of Accounting and Control) magnetic disk drive was the first device able to provide direct access of less than a second for reading and writing or updating individually a very large number of records. The RAMAC disk drive marked the beginning of a revolution in computing by introducing transaction processing systems, beginning the replacement of sequential processing, that required with the storage of databases on inherently serial access media like paper, magnetic tape and punched cards.
Among the radical innovations made to realize the RAMAC disk drive included
Brief History
IBM established a small "advanced technology" laboratory, the first on the West Coast, in San Jose in 1952. The size was limited to 50 people and the main purpose was to acquire engineering talent on the West Coast given the reluctance on so many there to move to the IBM Labs back East. Rey Johnson, an inventive genius, was put in charge and given free rein to focus on projects that sometime in the future may benefit IBM. This freedom and exploratory environment led to the concept of a mass storage device as a part of a transaction processing system.
Earlier punch card accounting relied on pre-punched cards storing frequently used data that would be manually accessed to avoid repunching for use in batch runs of new card data. Johnson believed a card to disk device could replace this “tub file”. From this concept to a transaction oriented processing system based on magnetic disk files was a journey requiring innovation and dedication. The two individual most responsible were Lou Stevens for the 350 disk file and John Haanstra for the 305 system
A key invention by Bill Goddard and John Lynott, implemented with an ingenious design by Norm Vogel, utilized a pressurized air bearing to mount the magnetic read/write element to maintain a constant spacing from somewhat wobbly disk surfaces.
Two key US Patents were obtained; 3,134,997, filed December 24, 1954 and granted on 5/19/64 to Stevens, Goddard and Lynott, claiming the basic RAMAC drive design and 3,503,060 to Goddard and Lynott, granted on 3/24/70 claiming floating heads and one or more heads per disk in the stack.
In recognition of their contributions, W. Goddard and J. Lynott were inducted into the Inventors Hall of Fame in 2007 and Lou Stevens was inducted in 2008.
The 350 RAMAC disk drive as the key component of the IBM 305 System demonstrated the value of magnetic disk storage to accounting and control applications. Today magnetic disk storage is pervasive in all computing applications and has become the way essentially all information is stored, and shared worldwide.
Additional Information
Bashe et al., "IBM'S Early Computers", MIT Press,1986, especially Chapter 8, "Disk Storage."
Collection Of Rey Johnson Papers at Computer History Museum
Kean, David W., "IBM San Jose, A Quarter Century Of Innovation”, 1977, CHM accession number: 102687875
US Patent 3,134,097; Data Storage Machine, L. Stevens, W Goddard, J Lynott, filed December 24, 1954 and granted in May 19, 1964
US Patent 3,503,060; Direct Access Magnetic Storage Disk Device, W Goddard, J Lynott, filed (backdated to December 24, 1964) and granted in March 24, 1970
"Aptos man (Lou Stevens) who led IBM Team is named to Inventors Hall of Fame," Santa Jose Mercury News April 16, 2008”