Source: wikibot/history-of-ibm-mainframe-operating-systems
= History of IBM mainframe operating systems
{wiki=History_of_IBM_mainframe_operating_systems}
The history of IBM mainframe operating systems is a fascinating journey that reflects the evolution of computing technology. Here's an overview of the key developments: \#\#\# 1. **Early Days (1950s)** - **IBM 701 (1952)**: IBM's first scientific computer, but it used a simple set of instructions and did not have a real operating system.