A Timeline of Mainframe Innovation

System/360 line of mainframes debuted on April 7

Six models

24 bit (16 MB) addressability

IBM promises any program that runs on one will run on all; kept promise on future models

Foundational architecture for all subsequent IBM mainframes

OS/360 and DOS/360 operating systems for the platform available as of 1966

Buzz Aldrin on the Moon in a photograph taken by Neil Armstrong.

IBM CICS teleprocessing monitor initial released

Allowing multiple users to concurrently access the same applications and data online

← Apollo 11 mission astronauts Neil Armstrong and Buzz Aldrin landed on the moon on July 20

Earth-based computing support by IBM System/360

IBM announced System/370 line of mainframes

Basis for virtualization and other innovations of the 1970s, including features such as Dynamic Address Translation

IBM System/370

The original Virtual Machine (VM/SP) introduced

The “original hypervisor” allowing multiple concurrent OS images of various IBM mainframe OSes

Multiple Virtual Storage (MVS/SP) announced

IBM issues Statement of Integrity for MVS and all subsequent versions

Four years later, in 1983, it became VSE/SP

In 1991 VSE/SP became VSE/ESA

In 2022 renamed VSEⁿ by 21CS

DOS/360, which became DOS/VS becomes DOS/VSE and eventually VSEⁿ

IBM announced the IBM System/370-XA (extended) architecture

31-bit XA addressing mode available while retaining compatibility with 24-bit addressing

Hardware platform for MVS/XA and VM/XA OSes

IBM introduced Enterprise Systems Architecture/370 (ESA/370)

Hardware platform for subsequently announced MVS/ESA, VM/ESA and VSE/ESA OSes

IBM announced the System/390 family

implementing the ESA/390 architecture

Transitioned from Bipolar to CMOS processor technology by the end of the decade

Soon became the platform for OpenEdition MVS, OS/390 and Unix System Services

IBM introduced Parallel Sysplex

Able to run and manage numerous workloads on multiple mainframes as if they were a single machine

Linux formally announced for IBM Mainframe,

along with Integrated Facility for Linux (IFL) specialty processor

Allowed Linux workloads to join the enterprise-class environment of the mainframe seamlessly

Able to run thousands of concurrent images on a single physical mainframe using hypervisors such as z/VM

64-bit memory addressability

Basis for z/OS, z/VM, z/VSE, z/TPF

Basis for specialty processors: IFL-2000, System z Application Assist Processor (zAAP, 2004) and System z Integrated Information Processor (zIIP, 2006)

IBM introduces System z hardware platform

Image courtesy of IBM

IBM announced LinuxONE

The first Linux-only mainframe

All the strengths of mainframe hardware and hypervisor technology focused on running massive numbers of Linux images concurrently on a single hardware instance

Zowe was introduced

Image courtesy of the Open Mainframe Project

An open source, extensible next generation graphical online environment for IBM mainframe users

Supported by contributions from numerous mainframe organizations, now notably including IBM, Broadcom, Rocket Software and Phoenix Software International