SYSTEM 1400/1800 IJMON A Bootable serial I/O monitor for loading programs.
BOS/360 Early interim version of DOS/360, briefly available at a few Alpha & Beta System 360 sites.
TOS/360 Similar to BOS above and more fleeting, able to boot and run from 2x00 series tape drives.
DOS/360 Disk Operating System. First commonly available OS for System/360 due to problems in the OS/360 Project. Multi-programming system with up to 3 partitions.
DOS/360/RJE DOS/360 with a control program extension that provided for the monitoring of Remote Job Entry hardware (Card Reader & Printer) connected by dedicated phone lines.
DOS/VSE First DOS offered on System/370 systems, provided Virtual Storage Extensions, and SNA. Still had fixed size processing partitions, but up to 14 partitions.
DOS/VSE/ESA DOS/VSE extended Virtual Storage Extensions support to 32 bit addresses (Extended System Architecture).
z/VSE Latest version of the four decades old DOS lineage. Now supports 64 bit addresses, Multiprocessing, Multiprogramming, SNA, TCP/IP, and some virtual machine features in support of Linux workloads. (All DOS ref. IBM website)
OS/360 First official OS targeted for the System/360 architecture, saw customer installations of the following variations:
PCP Primary Control Program, a kernel and a ground breaking automatic space allocating file system.
MFT Multi-Programming Fixed Tasks, had 15 fixed size partitions defined at boot time.
MVT Multi-Programming Variable Tasks, had up to 15 partitions defined dynamically.
RTOS Real Time Operating System, run on 5 NASA custom System/360/75s. A mash up by the Federal Systems Division of the MFT system management, PCP basic kernel and file system, with MVT task management and FSD custom real time kernel extensions and error management. The pinnacle of OS/360 development.
OS/370 The official port of OS/360 targeted for the System/370 virtual memory architecture. Customer installations in the following variations:
OS/VS1 Virtual-memory version of OS/MFT
OS/VS2 Virtual-memory version of OS/MVT
SVS Single Virtual Storage (both VS1 & VS2 began as SVS systems)
MVS Multiple Virtual Storage (eliminated any need for VS1)
OS/390 Upgrade to MVS, with an additional Unix-like environment.
