1. Introduction to Operating Systems
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2. 1.2. History of Operating Systems
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3. First generation(1945–1955): direct input
Around the mid-1940s, Howard Aiken at Harvard University, John von Neumann at Princeton, J. Presper Eckert and John Mauchley at the University of Pennsylvania, et al:
Vacuum tubes
Plug boards
Programming languages were unknown (even assembly language was unknown).
Operating systems were unheard of.
Run one job at a time
Enter it into the computer (might require rewiring!)
Run it
Record the results
Problem: lots of wasted computer time!
Computer was idle during first and last steps
Computers were very expensive!
Goal: make better use of an expensive commodity: computer time
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4. Second generation
1955 – 1965
Transistors
Batch systems
To run a job (i.e., a program or set of programs)
First write the program on paper (in FORTRAN or even in assembly)
Then punch it on cards
Bring cards to 1401
Read cards onto input tape
Put input tape on 7094
Telling the operating system to run the program
Perform the computation, writing results to output tape
Put output tape on 1401, which prints output
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5. Structure of a typical 2nd generation job
Data for program
$END
FORTRAN program
$RUN
$LOAD
$FORTRAN
$JOB, 10, , ETHAN MILLER
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6. Third generation 1965 – 1980 Multiple jobs in memory
Integrated circuits
Multiprogramming
Multiple jobs in memory
Protected from one another
Operating system protected from each job as well
Resources (time, hardware) split between jobs
Still not interactive
User submits job
Computer runs it
User gets results minutes (hours, days) later
Job 3
Job 2
Memory partitions
Job 1
Operating system
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7. Spooling Original batch systems used tape drives
Later batch systems used disks for buffering
Operator read cards onto disk attached to the computer
Computer read jobs from disk
Computer wrote job results to disk
Operator directed that job results be printed from disk
Disks enabled simultaneous peripheral operation on-line (spooling)
Computer overlapped I/O of one job with execution of another
Better utilization of the expensive CPU
Still only one job active at any given time
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8. Timesharing
Multiprogramming allowed several jobs to be active at one time
Multiprogramming were still basically batch systems
the time between submitting a job and getting back the output was often hours.
for example, a single misplaced comma could cause a compilation to fail, and the programmer to waste half a day.
a variant of multiprogramming is Timesharing system : for quick response time
CPU is switched among users’ programs (for interactive use)
Switching is done among active programs
CTSS (Compatible Time Sharing System):developed at MIT
MULTICS (developed by MIT, Bell Labs, and General Electric )
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9. Fourth generation: 1980 – present
LSI (Large-scale Integration) circuits
microprocessor-based personal computer
CP/M operating system (for 8-bit microprocessor)
MS-DOS (for 16-bit microprocessor)
32-bit systems: Mac OS X , Microsoft Windows, Unix and Linux
Next generation: ???
Systems connected by high-speed networks ?
Wide area resource management ?
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10. Types of modern operating systems
Mainframe operating systems: MVS
Server operating systems: FreeBSD, Solaris
Multiprocessor operating systems: Cellular IRIX
Personal computer operating systems: Windows, Unix
Real-time operating systems
Embedded operating systems
Smart card operating systems
Some operating systems can fit into more than one category
Got here on the first day of class.
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11. Real-time operating systems:
VxWorks : Developed by Wind River Systems of Alameda , California , USA in 1987
Binary, counting, and mutual exclusion semaphores with priority inheritance
Error handling framework
Fast, flexible inter-process communication including TIPC
IPv6 networking stack
Local and distributed message queues
Memory protection to isolate user applications from the kernel
Multitasking kernel with preemptive and round-robin scheduling and fast interrupt response
SMX: real-time multitasking operating system
specifically designed for embedded systems. SMX is a modular RTOS that meets the needs of small to medium-size embedded systems.
It supports ARM, Cortex, ColdFire, PowerPC, x86, and is portable to other processor families.
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12. Real-time operating systems:
A real-time operating system (RTOS) is a multitasking operating system intended for applications with fixed deadlines (real-time computing).
VxWorks : Developed by Wind River Systems of Alameda , California , USA in 1987
Binary, counting, and mutual exclusion semaphores with priority inheritance
Error handling framework
Fast, flexible inter-process communication including TIPC
Local and distributed message queues
Memory protection to isolate user applications from the kernel
Multitasking kernel with preemptive and round-robin scheduling and fast interrupt response
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13. Real-time operating systems:
SMX: real-time multitasking operating system
Specifically designed for embedded systems
SMX is a modular RTOS that meets the needs of small to medium- size embedded systems.
It supports ARM, Cortex, ColdFire, PowerPC, x86, and is portable to other processor families.
PORTOS: New Kind of RTOS
Portos is a very small, fast and easy RTOS
It does not use tasks: the priority levels are directly assigned to functions
The scheduler is very small and fast;
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14. ?
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