Posts Tagged ‘Retro computing’
In 1956, 5MB was big enough for anyone
In September 1956, IBM launched the 305 RAMAC (Random Access Method of Accounting and Control), the first commercial computer that used a moving-head hard disk drive (as opposed to sequential access magnetic tape storage).
The RAMAC’s disk storage unit, the IBM 350, weighed over a ton, had to be moved around with forklifts, and was delivered via large cargo airplanes (as above). It stored approximately 5MB of data: five million 8-bit characters on fifty 24-inch-diameter disks, a form of drum memory. It consisted of two independent access arms that moved up and down to select a disk, and in and out to select a recording track, all under servo control. The average time to locate a single record was 600ms (c.f. the seek times for modern hard disk drives of 5-10ms). IBM touted the system as being able to store the equivalent of 64,000 punched cards.
Over a thousand IBM 305 RAMAC systems were built, which were leased for $3,200 per month, equivalent to a purchase price of about $160,000 in 1957 dollars (approximately $1.3m today). The 305 was one of the last vacuum tube computers that IBM built, with production ending in 1961.
A representative for Hitachi Global Storage Technologies (which acquired IBM’s hard disk drive business in 2002), stated in a Wall Street Journal interview in 2006 that the storage capacity of the drive could have been increased beyond 5MB, but IBM’s marketing department was against a larger capacity drive because they were unsure how to sell a product with more storage…(oh, how times have changed).
(HT to Retronaut for this post)
