Operating Systems WT 2019/20
Abridged History of Operating Systems
Operating Systems 2
Something to Ponder
What is an Operating System?
try to come up with a definition of what the
term operating system means.
Discuss your findings amongst yourselves.
Operating Systems 5
Operating System Definition
My attempt:
An operating system is a program that runs and
orchestrates other programs, based on a set of
optimization criteria.
Operating Systems 6
Hardware and Software
Hardware Development
Operating System Development
Operating Systems 7
The First Computer
Q: What was the first computer?
Operating Systems 8
First Computers
● 1801: Power loom driven by wooden punch cards
● 1822: Steam- driven analytical engine by Charles Babbage
● Mechanical decimal stored ‐program computer,
programmable by punch cards, support for calculation and
conditional statements
● Remained unbuilt; Based on concepts, Ada Byron later
invented subroutines and loops as programming concepts
● 1890: U.S. census supported by Hollerith desk - punch card
reader, counting units, wall of dial indicators
● Built by Tabulating Machine Company, which eventually
became International Business Machines
● Invented the idea of output punch cards independent from
Babbage
Operating Systems 9
First Computers
● 1944: Harvard Mark I developed in partnership between Harvard
and IBM (ballistic firing tables)
● First programmable digital computer made in the U.S.
● Constructed of switches, relays, rotating shafts, clutches
● Grace Hopper found the first computer bug, invented
the predecessor of COBOL and the first compiler
● 1941: Konrad Zuse completed the work on the Z3
● First programmable electromechanical computer
● Punch film for program and data (lack of paper)
● Mapping of Boolean algebra to relays, developed independently
from original Shannon work
● Plankalkül – programming language
Operating Systems 10
Von Neumann Architecture
● 1946: ENIAC as first fully electronic computer in the U.S.
● No program memory, re-wiring for each program
● EDVAC: Revolutionary extension with a stored program computer concept by John von
Neumann
● Memory contains both the program and the data
● Introduction of a general purpose computer concept
Operating Systems 11
Serial Processing
● Computers from 1940 to 1955 were able to perform serial processing
● Programs for the machine (relays, vacuum tubes) written in assembly language
● Console with display lights, switches, punch card reader / plugboard, printer
● Re-wiring or punch card reading necessary for filling the program memory
● Program had complete control of the machine
for the entire run-time
● Manual reservation, user either finished early
(wasted time) or could not debug their problem
● Long setup time -
Job may involve running the compiler
program first and feeding in the output again
Operating Systems 13
1st Idea: Batch Processing
● A job control language (JCL) operates the monitor
application
● Instructions about the compiler to use, data to work on
etc. (Fortran prefix $)
● Early version of system calls
● Monitor needed to switch between itself and the
application
● Resident monitor parts always in memory
● Demands on hardware: memory protection, timer,
privileged instructions for I/O
● User mode vs. monitor mode (system mode, kernel
mode, supervisor mode)
Operating Systems 14
2nd Idea: Multiprogramming
● Batch processing increases utilization, but jobs still need to
wait for I/O operations
● Idea: Load multiple jobs into memory at the same time
● While one is waiting for I/O results, switch to another one
● Multiplexing of resources between a set of jobs became a
basic monitor / operating system task
-> multi-programming or multi-tasking
● Goal: Maximize CPU utilization
Operating Systems 15
2nd Idea: Multiprogramming
Operating Systems 16
2nd Idea: Multiprogramming
● Multiprogramming begets interactivity
● Idea: add dedicated job that is always loaded and
processes user input (“terminal”)
● Time Sharing Option (TSO) on IBM Mainframe
● Decouples the user from the processing
● But: multiprogramming is cooperative
→ terminal is unresponsive while the machine is occupied
Operating Systems 17
3rd Idea: Preemption / Time Sharing
● Users started to demand interaction with their program,
e.g. for retry on errors
● Perform multi-tasking, but act like the machine is exclusively used
● Advent of time-sharing / preemptive multi-tasking systems
● Goal: Minimize single user response time
● Extension of multi-programming to multiple interactive (non-batch)
jobs
● Preemptive multi-tasking became a single user demand in modern
times
● Leave one application running while starting another one
● Pure batch processing systems still exist: TPM, SAP R/3, HPC
Operating Systems 18
Time Sharing – CTSS & MULTICS
● Compatible Time-Sharing System (CTSS)
● Operating system developed at MIT, first for the IBM 7094 in 1961
(32.768 36bit words memory)
● Program always loaded to start at the location of the 5000th word
● System clock generated interrupts roughly every 0.2 seconds
● At each clock interrupt, the system regained control and assigned the processor to
another user - time slicing
● Parts of the active program that would be overwritten are written to disk
● Other parts remained inactive in the system memory
● Direct successor MULTICS pioneered many modern operating system concepts
Operating Systems 19
Time Sharing – CTSS & MULTICS
Source Code:
● https://gitlab.hpi.de/osm-teaching/opsys19labs/multics
● https://gitlab.hpi.de/osm-teaching/opsys19labs/ctss
… and more
Operating Systems 20
Genealogy of Operating Systems
55
60
65
70
75
80
85
90
95
00
03
IOCS
DOS/360
DOS/VSE
VSE
VSE/ESA
OS/360
MVS/370
MVS/XA
MVS/ESA
TSO
IBSYS
CTSS
CP/CM5
VM/370
VM/XA
VM/ESA
SYSTEM III
SYSTEM V
SYSTEM V.4
MULTICS
UNIX
UNIXV.7
AIX/370
AIX
SUN OS
POSIX
SOLARIS 2
4.1BSD
4.2BSD
4.3BSD
4.4BSD
MACH
OSF/1
AIX/ESA
XENIX MS-DOS 1.0
CP/M
DR/DOS
OS/2WIN 3.0
WIN NT
WIN 2000
WIN 9X
WIN XP
GNU/LINUX
RSX-11M
VMS 1.0
VMS 5.4
VMS 7.3
WIN 3.1
SOLARIS 10
RT-11
GNU/LINUX 2.6
WIN Server 2003
OS/390
z/OS
z/VSE z/VM
https://www.tele-task.de/lecture/video/7083/
from 49:50
Operating Systems 21
Genealogy of Unix (simplified)
OpenServer
6.x
UnixWare
7.x
(System V
R5)
HP-UX
11i+
1969
1971 to 1973
1974 to 1975
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001 to 2004
2006 to 2007
2008
2005
2009
2010
2011
2012 to 2015
2016
2017
Open source
Mixed/shared source
Closed source
HP-UX
1.0 to 1.2
OpenSolaris
& derivatives
(illumos, etc.)
System III
System V
R1 to R2
OpenServer
5.0.5 to 5.0.7
OpenServer
5.0 to 5.04
SCO UNIX
3.2.4
SCO Xenix
V/386
SCO Xenix
V/386
SCO Xenix
V/286
SCO Xenix
Xenix
3.0
Xenix
1.0 to 2.3
PWB/Unix
AIX
1.0
AIX
3.0-7.2
OpenBSD
2.3-6.1
OpenBSD
1.0 to 2.2
SunOS
1.2 to 3.0
SunOS
1 to 1.1
Unix/32V
Unix
Version 1 to 4
Unix
Version 5 to 6
Unix
Version 7
Unnamed PDP-7 operating system
BSD
1.0 to 2.0
BSD
3.0 to 4.1
BSD 4.2
Unix
Version 8
Unix
9 and 10
(last versions
from
Bell Labs)
NexTSTEP/
OPENSTEP
1.0 to 4.0
Mac OS X
Server
Mac OS X,
OS X,
macOS
10.0 to 10.12
(Darwin
1.2.1 to 17)
