# block-oriented terminal

> computer terminal which transfers data to/from the host an entire screen at a time instead of character by character

**Wikidata**: [Q4927118](https://www.wikidata.org/wiki/Q4927118)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Block-oriented_terminal)  
**Source**: https://4ort.xyz/entity/block-oriented-terminal

## Summary
A block-oriented terminal is a computer terminal that transfers data to and from the host computer an entire screen at a time, rather than character by character. This approach improves efficiency by reducing the number of data transmissions needed for screen updates. Block-oriented terminals were widely used with mainframe and midrange computer systems.

## Key Facts
- Transfers data to/from the host an entire screen at a time instead of character by character
- IBM 3270 was introduced by IBM in 1971 as a family of block-oriented computer terminals
- IBM 2260 was a block-oriented computer terminal released by IBM in 1964
- IBM 5250 is a family of block-oriented terminals used with IBM midrange computer systems (System/34, System/36, System/38, AS/400)
- HP 2640 terminals were block-mode serial terminals produced by Hewlett-Packard using Intel 8008 and 8080 microprocessors
- Bull Questar terminals were 3270-compatible computer terminals manufactured by Groupe Bull and widely used in France

## FAQs
### Q: What is the main difference between a block-oriented terminal and a character-oriented terminal?
A: A block-oriented terminal transfers an entire screen of data at once to/from the host computer, while a character-oriented terminal sends data one character at a time. This makes block-oriented terminals more efficient for applications that display full screens of information.

### Q: What are some examples of block-oriented terminals?
A: Notable examples include the IBM 3270 (introduced in 1971), IBM 2260 (released in 1964), IBM 5250 (used with midrange systems), HP 2640, and Bull Questar terminals. The VT61 and VT62 from DEC were also block-mode terminals.

### Q: Why were block-oriented terminals important in computing history?
A: Block-oriented terminals were crucial for efficient data entry and display in mainframe and midrange computing environments. They reduced network traffic and improved response times for applications that worked with full-screen forms, making them ideal for business applications, transaction processing, and data entry systems.

## Why It Matters
Block-oriented terminals represented a significant advancement in computer-human interaction by optimizing data transfer between terminals and host systems. Before their introduction, character-oriented terminals sent each keystroke individually to the host, creating substantial network overhead and slower response times. Block-oriented terminals solved this by allowing users to fill out entire screens locally, then transmit all changes at once when ready. This innovation was particularly important for business applications, airline reservation systems, banking terminals, and other transaction processing systems where efficiency and speed were critical. The technology enabled more sophisticated user interfaces and forms-based applications that could run effectively over the limited bandwidth available in early computer networks. Even as personal computers became dominant, the concepts behind block-oriented terminals influenced later client-server architectures and web-based applications that batch data transfers for efficiency.

## Notable For
- Introduced the concept of local screen editing before transmission to the host
- Significantly reduced network traffic compared to character-oriented terminals
- Enabled sophisticated forms-based applications on early computer systems
- Became the standard interface for IBM mainframe and midrange computing environments
- Influenced the development of later client-server and web-based application architectures

## Body
### Technical Operation
Block-oriented terminals work by maintaining a local copy of the screen contents and only transmitting changes when the user submits the form or navigates away from the screen. This is fundamentally different from character-oriented terminals where every keystroke is immediately sent to the host for processing. The terminal typically uses function keys or special commands to indicate when data should be transmitted back to the host system.

### Historical Development
The evolution from character-oriented to block-oriented terminals paralleled the growth of interactive computing in business environments. Early terminals like the IBM 2260 (1964) established the basic concept, while later models like the IBM 3270 (1971) refined the technology with better display capabilities and more sophisticated data handling. The IBM 5250 series extended these concepts to midrange systems, creating a consistent interface across different computing platforms.

### Applications and Use Cases
Block-oriented terminals found their primary use in transaction processing systems, airline reservation systems (like SABRE), banking terminals, inventory management, and other business applications where users needed to enter or view structured data. The ability to edit data locally before transmission made these systems practical for high-volume data entry operations and applications requiring complex data validation.

### Legacy and Influence
While largely replaced by personal computers and web-based interfaces, the concepts behind block-oriented terminals continue to influence modern computing. The idea of local editing with batch updates appears in many web applications, and the efficiency principles guided the development of thin client architectures and terminal emulation software that remains important in enterprise computing environments.

## Schema Markup
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  "@type": "Thing",
  "name": "Block-oriented terminal",
  "description": "Computer terminal which transfers data to/from the host an entire screen at a time instead of character by character",
  "sameAs": [
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## References

1. BabelNet