# PDP-10

> mainframe computer family from DEC

**Wikidata**: [Q1568240](https://www.wikidata.org/wiki/Q1568240)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/PDP-10)  
**Source**: https://4ort.xyz/entity/pdp-10

## Summary
The PDP-10 is a mainframe computer family manufactured by Digital Equipment Corporation (DEC). It is a 36-bit processor and instruction set architecture that succeeded the earlier PDP-6. The system is characterized by its big-endian data format and specific hardware components, including 16 processor registers and an 18-bit address bus.

## Key Facts
- **Classification:** The PDP-10 is a mainframe computer, a computing platform, and a processor classified under the "Programmed Data Processor" line.
- **Manufacturer:** Digital Equipment Corporation (DEC).
- **Architecture:** It utilizes a 36-bit data size and big-endian byte ordering.
- **Predecessor:** The architecture is based on and replaces the PDP-6.
- **Registers:** The system features 16 processor registers, each with a size of 36 bits.
- **Addressing:** It employs an 18-bit address bus and an 18-bit program counter.
- **Flags:** The processor includes 13 flags used for functions such as arithmetic overflow, carry, byte addressing, and ring operations.
- **Aliases:** Also known as the DEC-10, decstation-10, and PDP 10.

## FAQs
### Q: What company manufactured the PDP-10?
A: The PDP-10 was manufactured by Digital Equipment Corporation (DEC).

### Q: What is the word size and architecture of the PDP-10?
A: The PDP-10 uses a 36-bit data size (word length) and employs big-endian byte ordering. It is based on the architecture of the earlier PDP-6.

### Q: What are the specific hardware components included in the PDP-10 processor?
A: The PDP-10 contains 16 processor registers (36-bit), an 18-bit address bus, a single 18-bit program counter, and 13 distinct flags for system operations.

## Why It Matters
The PDP-10 represents a significant evolutionary step in DEC's line of Programmed Data Processors, serving as a bridge between the earlier PDP-6 and subsequent computing platforms. As a 36-bit mainframe, it offered a distinct architectural approach compared to the more common 8-bit or 16-bit systems of its era, allowing for different precision levels in data processing.

Its design as both an instruction set architecture and a physical computing platform provided a robust environment for complex computations. The system's inclusion of features like memory-mapped files and index registers within its 16 general-purpose registers highlighted its capability for sophisticated memory management. Furthermore, its association with entities like MIT-AI underscores its historical role in advanced computing research and artificial intelligence applications during its operational lifetime.

## Notable For
- **36-bit Architecture:** Distinguished by its 36-bit data size, a characteristic inherited from the PDP-6.
- **Instruction Set:** Classified specifically as an instruction set architecture as well as a physical machine.
- **Flag System:** Features a comprehensive set of 13 flags managing arithmetic overflow, carry, byte addressing, and ring protection.
- **Lineage:** Directly succeeded and replaced the PDP-6 while maintaining architectural similarities.

## Body
### Technical Specifications
The PDP-10 is defined by its distinct internal structure and data handling capabilities. As a 36-bit processor, it processes data in larger chunks than many of its contemporaries.

*   **Data Handling:** The system uses a 36-bit data size with big-endian formatting.
*   **Registers:** It is equipped with 16 processor registers. Each register is 36 bits wide and supports characteristics such as memory-mapped files and index registers.
*   **Addressing and Control:** The address bus is 18 bits wide, matching the width of the program counter (1 unit, 18 bits).

### System Flags
The processor utilizes a set of 13 flags to manage various operational states. These flags are utilized for:
*   Arithmetic overflow
*   Carry
*   Byte addressing
*   Ring (protection levels)

### Identity and Lineage
The PDP-10 is a member of the Programmed Data Processor class and falls under the broader categories of mainframe computers and computing platforms. It was marketed and known under several aliases, including DEC-10 and decstation-10. The system explicitly replaces the PDP-6, serving as the next generation of that hardware lineage. It is related to the MIT-AI entity, identifying it as a specific PDP-10 computer instance.

## References

1. [Source](https://github.com/JohnMarkOckerbloom/ftl/blob/master/data/wikimap)
2. Freebase Data Dumps. 2013
3. BabelNet
4. [Source](http://www.bitsavers.org/www.computer.museum.uq.edu.au/pdf/DEC-10-HMAA-D%20PDP-10%20KA10%20Central%20Processor%20Maintenance%20Manual%20Volume%20I.pdf)
5. National Library of Israel Names and Subjects Authority File