IBM 2540
| Company type | Peripheral device |
|---|---|
| Industry | Computer hardware |
| Founded | 1965 |
| Headquarters | Rochester, Minnesota , United States |
| Products | Punched-card reader and punch |
| Parent | IBM Corporation |
The IBM 2540 is a punched-card peripheral device produced by IBM Corporation intended for use with the System/360 series and subsequent models. Developed by IBM's Data Processing Division in Rochester, Minnesota, it made its debut in 1965. This unit reads punched cards at a speed of 1000 cards per minute (CPM) and punches at 300 CPM, building upon the foundation set by the somewhat slower IBM 1402.
Description
The 2540 interfaces with a System/360 multiplexer or selector channel through an IBM 2821 Control Unit. It handles IBM-standard 80-column punched cards. The card reader (2540R) and card punch (2540P) are individually addressable and function independently, commonly processing data encoded in EBCDIC format (data-mode 1).
Card reader
Positioned on the right side, the reader features an input hopper capable of holding roughly 3100 cards, along with three output stackers labeled R1, R2, and RP3, each accommodating about 1350 cards. The routing of output cards can be configured as needed.
Card punch
Situated on the left, the punch section includes an input hopper with a capacity near 1350 cards and three output stackers—P1, P2, and RP3—each designed to hold approximately 1350 cards. The RP3 stacker is shared between both reader and punch units but cannot be used by both simultaneously. Post-punching, cards are read to confirm punching accuracy.
Special features
- Column binary mode (data-mode 2): Permits reading or punching of every possible hole combination within a column.
- Punch-feed-read capability: Allows the punch unit to read input cards while concurrently punching data on them; this feature is seldom supported by spooling software.
- 51-column Interchangeable Read Feed: Facilitates reading of 51-column "stub" cards alongside standard 80-column cards, requiring manual operator configuration. This reduces stacker capacities for R1 and R2 to approximately 800 cards each and decreases reading speed to 800 CPM.
Successors
Following the launch of System/370, IBM introduced upgraded punched card devices in 1971: the 3525 card punch and the 3505 card reader, which enhanced their punched card technology lineup.