IBM 1402
| Company type | Product |
|---|---|
| Industry | Computer hardware |
| Founded | October 5, 1959 |
| Products | Punched card reader and punch device |
The IBM 1402 functioned as a rapid Punched card reader and punch device, launched on October 5, 1959, to serve as an input/output accessory for the IBM 1401 system. Subsequently, it was incorporated into additional machines within the IBM 1400 series and IBM 7000 series families. Its architecture influenced the design of the IBM 1622 Card Read-Punch used with the IBM 1620, and it also laid the groundwork for peripherals in the IBM System/360 lineup, including models IBM 2501, IBM 2520, and IBM 2540.
Card reader
- Capable of reading cards at speeds reaching 800 per minute on models 1, 2, and 3, while models 4, 5, and 6 operate at up to 450 cards per minute.
- The input hopper holds up to 3,000 cards for models 1 through 4 and model 6; model 5's hopper accommodates approximately 1,200 cards.
- Equipped with three output stackers labeled NR, 1, and 2/8, each able to contain around 1,000 cards.
Card punch
- All variants punch cards at a maximum rate of 250 per minute.
- The feed hopper capacity is set at 1,200 cards.
- Three output stackers—NP, 4, and a shared stacker (2/8)—each offer about a 1,000-card capacity; however, the shared stacker restricts merging due to timing limitations.
- An optional feature enables the punch unit to read cards from its feed.
Punched card format
This device supports IBM’s standard 80-column punched card format but also offers compatibility with a 51-column option. A column binary function permits reading and punching cards with any combination of holes.
Error checking
The reader and punch units independently tally holes in every column at different checkpoints. If discrepancies arise between these counts—and if the I/O check stop switch is activated—the mechanism halts and signals an error.
Moreover, when operating outside of column-binary mode, the reader ceases operation if it encounters a punched column that does not correspond to a recognized character.