# IBM 3720

> IBM mainframe communications controller introduced in 1986

**Wikidata**: [Q5968651](https://www.wikidata.org/wiki/Q5968651)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/IBM_3720)  
**Source**: https://4ort.xyz/entity/ibm-3720

## Summary  
The IBM 3720 is a mainframe communications controller that IBM introduced in 1986. It belongs to the IBM 37xx family of small computers that attach to an IBM mainframe and perform networking functions on the mainframe’s behalf.

## Key Facts  
- **Introduced:** 1986 (IBM 3720)【source】  
- **Category:** Mainframe communications controller【source】  
- **Series:** Member of the IBM 37xx class of communication controllers【source】  
- **Manufacturer:** International Business Machines (IBM)【source】  
- **Subclass:** IBM 37xx【source】  
- **Identifiers:** Foldoc ID `IBM+3720`; Freebase ID `/m/0jf7g`【source】  
- **Wikipedia entry:** Title “IBM 3720”, available in English and Indonesian【source】  
- **Sitelink count:** 2 Wikipedia sitelinks【source】  

## FAQs  
### Q: What was the IBM 3720 used for?  
A: The IBM 3720 acted as a communications controller, handling networking tasks for an attached IBM mainframe so the mainframe could focus on its core processing work.  

### Q: When did IBM release the 3720 model?  
A: IBM launched the 3720 in 1986 as part of its 37xx series of communication controllers.  

### Q: How does the IBM 3720 relate to the IBM 37xx series?  
A: The 3720 is a specific model within the IBM 37xx class, which is a family of small computers designed to provide networking functions for IBM mainframes.  

### Q: Is the IBM 3720 still manufactured today?  
A: No. The IBM 3720 was introduced in 1986 and is no longer in production; it belongs to a historic line of IBM mainframe communication controllers.  

### Q: Where can I find more information about the IBM 3720?  
A: Additional details are available on its Wikipedia page (English and Indonesian) and through identifiers such as the Foldoc and Freebase entries.  

## Why It Matters  
During the era of large‑scale mainframe computing, connecting those powerful systems to external networks required dedicated hardware. The IBM 3720 fulfilled this need by serving as a specialized communications controller, offloading networking responsibilities from the mainframe itself. As part of the broader IBM 37xx series, the 3720 exemplified IBM’s strategy of modularizing system functions—allowing organizations to extend mainframe capabilities without redesigning the core computer. This approach helped enterprises integrate mainframes into emerging data‑communication environments of the mid‑1980s, paving the way for more flexible, network‑aware enterprise architectures. Understanding the IBM 3720 provides insight into the evolution of mainframe networking and IBM’s role in shaping enterprise connectivity standards.  

## Notable For  
- Being introduced in 1986 as a dedicated networking controller for IBM mainframes.  
- Belonging to the IBM 37xx family, a recognized series of small, attachable computers for mainframe communication.  
- Providing a clear separation of networking duties from the mainframe’s processing workload.  
- Carrying unique identifiers (Foldoc `IBM+3720`, Freebase `/m/0jf7g`) that aid in scholarly and technical referencing.  

## Body  

### Overview  
- The IBM 3720 is classified as a **mainframe communications controller**.  
- Its primary function is to manage **networking operations** for an attached IBM mainframe.  

### Historical Context  
- Released in **1986**, the 3720 arrived at a time when enterprises were expanding their data‑communication needs.  
- It complemented IBM’s broader strategy of offering **modular hardware components** that could be added to existing mainframe installations.  

### Technical Role  
- As a **small computer**, the 3720 connects directly to the mainframe’s I/O channels.  
- It executes networking protocols and data‑transfer tasks, thereby **offloading these responsibilities** from the mainframe CPU.  

### Relationship to the IBM 37xx Series  
- The 37xx series is defined as a **class of mainframe communication controllers** produced by IBM and, later, by clone manufacturers.  
- The 3720 is a **subclass** within this series, sharing the series’ core design philosophy of providing dedicated networking hardware.  

### Legacy and Documentation  
- The model is documented under the Wikipedia title **“IBM 3720”** with entries in **English and Indonesian**.  
- It is indexed in technical databases with a **Foldoc ID** (`IBM+3720`) and a **Freebase ID** (`/m/0jf7g`).  

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*All statements are derived from the supplied source material.*