# OS/390

> 31-bit operating system for IBM mainframes

**Wikidata**: [Q1726891](https://www.wikidata.org/wiki/Q1726891)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/OS/390)  
**Source**: https://4ort.xyz/entity/os-390

## Summary
OS/390 is a 31-bit operating system developed by IBM for IBM mainframes. It was introduced in 1995 and replaced the MVS operating system.

## Key Facts
- OS/390 is a 31-bit operating system
- It was developed by IBM
- It was released in 1995
- It replaced the MVS operating system
- It runs on the IBM S/390 platform
- It is an instance of operating system software
- It has entries in 11 different language versions of Wikipedia
- Its freebase ID is /m/09rkx

## FAQs
### Q: What is OS/390?
A: OS/390 is a 31-bit operating system developed by IBM for IBM mainframes, introduced in 1995 to replace the MVS operating system.

### Q: What platforms does OS/390 run on?
A: OS/390 is designed to run specifically on the IBM S/390 platform of mainframe computers.

### Q: When was OS/390 released?
A: OS/390 was first released in 1995.

### Q: What operating system did OS/390 replace?
A: OS/390 replaced the MVS (Multiple Virtual Storage) operating system.

## Why It Matters
OS/390 represents a significant evolution in IBM's mainframe operating systems, bringing 31-bit addressing capabilities to enterprise computing. It enabled more efficient memory utilization for large-scale business applications in the era when mainframes dominated corporate data centers. As a successor to MVS, it maintained backward compatibility while introducing new features that improved system management, availability, and scalability for mission-critical applications. OS/390 laid the foundation for modern IBM z/OS, continuing the lineage of IBM's most robust enterprise operating systems that power many of the world's financial institutions, government agencies, and large corporations.

## Notable For
- Being IBM's flagship operating system for mainframes during the mid-to-late 1990s
- Supporting 31-bit addressing, allowing for larger memory utilization than previous systems
- Implementing extensive security features for enterprise environments
- Providing a stable platform for mission-critical business applications
- Maintaining backward compatibility with its predecessor, MVS

## Body
### Overview
OS/390 is an operating system developed by IBM specifically for IBM mainframe computers, particularly the IBM S/390 platform. It was first released in 1995 as a successor to the MVS (Multiple Virtual Storage) operating system.

### Technical Specifications
- 31-bit operating system architecture
- Designed for enterprise computing environments
- Runs exclusively on IBM S/390 hardware platform
- Provides support for large-scale business applications

### Historical Context
- Released in 1995
- Replaced the MVS operating system
- Served as a predecessor to modern z/OS
- Part of IBM's enterprise operating system lineage
- Was available in multiple language editions (German, English, Spanish, French, Hebrew, Italian, Japanese, Korean, Norwegian, Polish)

### Development
- Developed by IBM, the American multinational technology corporation founded in 1911
- Represents a significant evolution in IBM's mainframe operating systems
- Built upon the foundation of MVS while adding new capabilities
- Designed to meet the growing demands of enterprise computing in the 1990s

## References

1. Freebase Data Dumps. 2013