Announced October 27, 1958 and withdrawn December 1, 1975.

     The IBM 46 supplemented punched cards and magnetic tape as a medium for machine-readable information. Data was entered from five- or eight-channel tape at speeds up to 20 characters per second. Up to three of these machines could be attached to an IBM 650 system.

     Announced October 27, 1958 and withdrawn January 9, 1979.

     The IBM 47 supplemented punched cards and magnetic tape as a medium for machine-readable information. Data was entered from five- or eight-channel tape at speeds up to 20 characters per second. Up to three machines could be attached to an IBM 650 system.

     Announced September 4, 1956 and withdrawn August 18, 1969.

     The addition of disk storage to the IBM 650 made possible "single step processing." Instead of accumulating data to be processed in stages, transactions could now be processed randomly as they occurred and every record affected by the transaction could be automatically adjusted in the same processing step. Each IBM 355 held 50 disks subdivided on each side into tracks for the storage of almost all active accounting records. Up to four IBM 355 units could be connected to the 650 system. (The 650 RAMAC fact sheet of September 14, 1956 provides specifications and performance information for the IBM 355.)

     Announced July 19, 1949 and withdrawn December 17, 1976.

     The IBM 407 was used with the 650 system for printed output and punched card input. It listed information, sent data to the 650 to be processed, and accepted results from the 650 for printing, storing or accumulating. Up to three 407s with or without summary punches could be attached to the 650, provided the combined total of 407s, IBM 533s and IBM 537s did not exceed three. (The Feeds & speeds page provides IBM 407 performance data and the 650 technical fact sheet of July 20, 1955 describes the machine's operation.)

     Announced July 2, 1953 and withdrawn August 18, 1969.

     The IBM 533 entered or extracted information from the 650 system in punched card form. It had two feeds. One read input data and instructions; the other punched output results. It could process 200 cards per minute in input or 100 cards a minute in output. (The Feeds & speeds page lists IBM 533 features.)

     Announced September 4, 1956 and withdrawn August 18, 1969.

     The IBM 537 entered or extracted information from the 650 system in punched card form. It had only one feed. Information was read from a card and processed; output results were punched into the same card. It processed 155 cards per minute.

     Announced January 12, 1959 and withdrawn August 18, 1969.

     The IBM 543 accelerated data processing by entering data from punched cards at rates up to 250 cards a minute. Information was read from the cards and transmitted to the 650. Alphabetical field and class selection abilities offered the user the means to change the arrangement of input data.

     Announced January 12, 1959 and withdrawn August 18, 1969.

     The 544 provided output speed of up to 250 punched cards per minute. An offset stacker was available as optional equipment.

     Announced July 14, 1953 and withdrawn August 18, 1969.

     The IBM 650 served as the central processing unit for all input-output combinations. It housed the magnetic drum storage, arithmetical device and the operator's console.

     Announced May 3, 1955 and withdrawn August 18, 1969.

     The IBM 652 furnished power for, and controlled the operation of, the 650's magnetic tape units, and contained the control circuitry for both tape units and disk storage units.

     Announced May 3, 1955 and withdrawn from marketing August 18, 1969.

     The IBM 653 was used for immediate access storage, indexing registers and automatic floating decimal arithmetic. It was an integral component of tape processing combinations, and was available separately as high-speed "working" storage to increase the 650's processing speeds. It received blocks of information -- data and instructions -- transferred from the drum in single operations. These blocks were then individually processed from core storage. As soon as one block had been processed, a new one was transferred in for processing, and so on. In this fashion, the problem was worked from core storage instead of the drum.

     Announced October 7, 1957 and withdrawn August 18, 1969.

     The IBM 654 was used for increased alphabetic input-output capacity.

     Announced May 5, 1955 and withdrawn August 18, 1969.

     The IBM 655 contained the 650's power supplies and was the only unit connected to the power source. In addition, the 655 provided for communication between the IBM 650 and the IBM 533.

     Announced September 25, 1953 and withdrawn May 12, 1971.

     The 727 was used for high-speed input-output processing of magnetic tape records. This medium permitted vast files of data to be condensed into small reels, thereby yielding an economy of file storage as well as file handling, and greater processing speeds. Historical data subject to repetitive use -- such as personnel and payroll records, and customer and production information -- was efficiently recorded on magnetic tape at a density of 200 characters per inch. As many as six IBM 727 units could be used with the 650 system. (The 650 RAMAC technical fact sheet describes the 727's use with the IBM 650.)

     Announced September 20, 1955.

     The IBM 838 placed facts stored in the 650's disk storage at the user's fingertips. The inquiry station transmitted requests for specific information, such as the status of an account, to disk storage. The requested data were immediately located and typed out at any desired station. In addition, during processing operations, the 838 could bring to management's attention specific results of particular interest or significance, and it could also introduce limited amounts of data into the 650.