IBM CPC
| Company type | Electronic calculator |
|---|---|
| Industry | Computing |
| Predecessor | IBM 604, IBM 605 |
| Founded | May 1949 |
| Products | CPC, CPC-II |
| Parent | IBM |
The IBM Card-Programmed Electronic Calculator (CPC) was introduced by IBM in May 1949, with an enhanced model, the CPC-II, released later that same year. These vacuum tube-based electronic calculators were capable of executing intricate computations, including division operations.
Instead of using punched cards to directly dictate operations, the CPC employed them to choose "microprograms" that were physically wired into the plugboard of either the IBM 604 or IBM 605 calculators. The outcome varied depending on the specific plugboard configuration used with identical punched cards. This system could hold up to 10 instructions and repeat their execution as needed.
The initial CPC setup consisted of:
- Electronic Calculating Punch:
- Accounting Machine:
For the CPC-II, the arrangement included:
- Electronic Calculating Punch:
- Accounting Machine:
- Optional Auxiliary Storage Devices (up to three units):
- IBM 941, each capable of storing 16 decimal numbers (each number comprising ten digits plus a sign)
According to IBM Archives, the CPC was engineered as a flexible general-purpose computing device designed to carry out fixed arithmetic sequences encoded on standard 80-column punched cards. It could choose instruction sets based on previous operations and retain instructions for self-modifying programming. The components were linked via adaptable cables and could also function independently; for example, the Type 605 operated as a standalone calculating punch, and the Type 527 punch unit was usable on its own.
Deliveries to customers started in late 1949, with over twenty systems ordered by government bodies, research laboratories, and aircraft manufacturers. Throughout the early 1950s, nearly 700 CPC units were shipped.
See also
References
- IBM, IBM Card-programmed Electronic Calculator; Model A1 using machine types 412-418, 605, 527, and 941, October 1954
- John W. Sheldon and Liston Tatum, "The IBM Card-Programmed Electronic Calculator," Joint AIEE-IRE Computer Conference, December 1951
- E.A. Barber, "Cam Design Calculations on the Card Programmed Electronic Calculator," Proceedings, Seminar on Scientific Computation, November 1949
- Cuthbert Hurd, "The IBM Card-Programmed Electronic Calculator," Proceedings, Seminar on Scientific Computation, November 1949
- IBM, Proceedings, Computation Seminar August 1951 – includes multiple articles on the IBM CPC and 604