The IBM 650 Magnetic Drum Data-Processing Machine
This generation of computers marked the beginning of mass production of computers, and it is one of the IBM’s early inventions in the history of computers. The system was released in 1954 but was still under the development stage. It consisted of three units: Power Unit, Card Reader Punch Unit, and Console Unit which had the magnetic drum used for storage, vacuum tubes for performing arithmetic, and the operator’s console. The rotating drum offered up to 4,000 words with a fixed time clocking at 2.5ms. The words were accessed when the drum rotated (12,000 RPM – Revolutions per Minute), and the needed section passes over the read/write heads. The company realized a sale of 450 machines within a year!