Interface
... With one user, do jobs need to time-share? Early PC OSes could only do one thing at a time Everything waited while printing/loading a program (Mac < X) ...
... With one user, do jobs need to time-share? Early PC OSes could only do one thing at a time Everything waited while printing/loading a program (Mac < X) ...
Operating Systems
... o virtual address (Pentium logical address) segment reference 2-bit protection mechanism 14-bit segment specification offset 32-bit o unsegmented memory virtual memory = 232 bytes, i.e., 4 GBytes o segmented memory virtual memory = 246 bytes, i.e., 64 TBytes ½ virtual address space == ...
... o virtual address (Pentium logical address) segment reference 2-bit protection mechanism 14-bit segment specification offset 32-bit o unsegmented memory virtual memory = 232 bytes, i.e., 4 GBytes o segmented memory virtual memory = 246 bytes, i.e., 64 TBytes ½ virtual address space == ...
Fundamental Concepts of Operating Systems
... Fundamental Concepts of Operating Systems Prof. Lixin Tao Pace University December 4, 2002 Chapter 1: Introduction ...
... Fundamental Concepts of Operating Systems Prof. Lixin Tao Pace University December 4, 2002 Chapter 1: Introduction ...
Course Syllabus
... An operating system is an abstraction of computer system hardware; it manages the sharing of various hardware and software resources among the users of the computer system. The parallel history of hardware and operating system development introduces many key concepts including, for example, processo ...
... An operating system is an abstraction of computer system hardware; it manages the sharing of various hardware and software resources among the users of the computer system. The parallel history of hardware and operating system development introduces many key concepts including, for example, processo ...
Interfacing with the Operating System
... • The operating system provides system calls for opening, reading, writing and closing files. • When you open a file in "C" (or Java) you will be invoking the appropriate operating system call. • Opening a file involves locating it, and bringing into memory information necessary to access it. • Read ...
... • The operating system provides system calls for opening, reading, writing and closing files. • When you open a file in "C" (or Java) you will be invoking the appropriate operating system call. • Opening a file involves locating it, and bringing into memory information necessary to access it. • Read ...
MIDTERM #1 - School of Computer Science
... 2. An operating system may be viewed as a resource allocator of such things as CPU time, memory space, file-storage space, I/O devices, and so on, due to the requirement that _________ . A) such things need to allocated to be useful for operating systems to work B) conflicts of resource usage must n ...
... 2. An operating system may be viewed as a resource allocator of such things as CPU time, memory space, file-storage space, I/O devices, and so on, due to the requirement that _________ . A) such things need to allocated to be useful for operating systems to work B) conflicts of resource usage must n ...
03-60-330-01 Winter 2010 - School of Computer Science
... A) making sure each layer is easily converted to modules B) making sure that each layer hides certain data structures, hardware, and operations from higher-level layers C) appropriately defining the various layers D) debugging a particular layer ...
... A) making sure each layer is easily converted to modules B) making sure that each layer hides certain data structures, hardware, and operations from higher-level layers C) appropriately defining the various layers D) debugging a particular layer ...
Operating Systems - KSU Web Home
... An application requests an operating system to perform an operation by using a Software ...
... An application requests an operating system to perform an operation by using a Software ...
What is an operating system (OS)?
... 3) Restrict a user program to its allocated address space. In a simple computer, a user program might be allocated a single continguous address space in memory. The two special purpose CPU registers: StartMemory and EndMemory can bracket the user program's address space. All memory addresses that th ...
... 3) Restrict a user program to its allocated address space. In a simple computer, a user program might be allocated a single continguous address space in memory. The two special purpose CPU registers: StartMemory and EndMemory can bracket the user program's address space. All memory addresses that th ...
OPERATING SYSTEMS QUESTIONS
... 10. What is the cause of thrashing? How does the system detect thrashing? Once it detects thrashing, what can the system do to eliminate this problem? - Thrashing is caused by under allocation of the minimum number of pages required by a process, forcing it to continuously page fault. The system can ...
... 10. What is the cause of thrashing? How does the system detect thrashing? Once it detects thrashing, what can the system do to eliminate this problem? - Thrashing is caused by under allocation of the minimum number of pages required by a process, forcing it to continuously page fault. The system can ...
Operating-System Structure
... appropriately defining the various layers. Because a layer can use only lower-level layers, careful planning is necessary A final problem with layered implementations is that they tend to be less efficient than other types. These limitations have caused a small backlash against layering in rec ...
... appropriately defining the various layers. Because a layer can use only lower-level layers, careful planning is necessary A final problem with layered implementations is that they tend to be less efficient than other types. These limitations have caused a small backlash against layering in rec ...
An operating system - Bilkent University Computer Engineering
... – Each user has at least one program executing in memory process – If several jobs ready to run at the same time CPU scheduling – If processes don’t fit in memory, swapping moves them in and out to run – Virtual memory allows execution of processes not completely in memory ...
... – Each user has at least one program executing in memory process – If several jobs ready to run at the same time CPU scheduling – If processes don’t fit in memory, swapping moves them in and out to run – Virtual memory allows execution of processes not completely in memory ...
Word Processors
... In order for the OS to function correctly it must be able to communicate with all hardware devices attached to the computer, A device driver are instructions for the OS on how to communicate with each device, In order for a piece of hardware to work properly its own driver needs installing – it also ...
... In order for the OS to function correctly it must be able to communicate with all hardware devices attached to the computer, A device driver are instructions for the OS on how to communicate with each device, In order for a piece of hardware to work properly its own driver needs installing – it also ...
What Is Operating System? Operating Systems, System Calls, and Buffered I/O
... close closes a file descriptor, so that it no longer refers to any file and may be reused. Any locks held on the file it was associated with, and owned by the process, are removed (regardless of the file descriptor that was used to obtain the lock) . . . . ...
... close closes a file descriptor, so that it no longer refers to any file and may be reused. Any locks held on the file it was associated with, and owned by the process, are removed (regardless of the file descriptor that was used to obtain the lock) . . . . ...
ppt
... • A process is an abstraction that supports running programs • Different processes may run several instances of the same program • In most systems, processes form a tree, with the root being the first process to be created • At a minimum, the following resources are required: – Memory to contain the ...
... • A process is an abstraction that supports running programs • Different processes may run several instances of the same program • In most systems, processes form a tree, with the root being the first process to be created • At a minimum, the following resources are required: – Memory to contain the ...
Hold and wait
... Multiprocessor systems also known as parallel systems, tightlycoupled systems are growing in importance. Such systems have two or more processors in close communication. Multiprocessor system have three advantage. 1. Increased throughput – by increasing the number of processors, we expect to get mor ...
... Multiprocessor systems also known as parallel systems, tightlycoupled systems are growing in importance. Such systems have two or more processors in close communication. Multiprocessor system have three advantage. 1. Increased throughput – by increasing the number of processors, we expect to get mor ...
operating systems structures
... I/O Operations: A running program may require I/O, which may involve a file or an I/O device. For efficiency and protection user usually cannot control I/O devices directly. The OS provides a means to do I/O. ƒ File System Manipulation: Programs need to read, write files. Also they should be able to ...
... I/O Operations: A running program may require I/O, which may involve a file or an I/O device. For efficiency and protection user usually cannot control I/O devices directly. The OS provides a means to do I/O. ƒ File System Manipulation: Programs need to read, write files. Also they should be able to ...
Computing Systems Division
... simple monochrome VDU displays meant that users could now communicate directly with running computer and not just indirectly via a computer operator. ...
... simple monochrome VDU displays meant that users could now communicate directly with running computer and not just indirectly via a computer operator. ...
Lesson 1 Communicating with the System - people
... Are sent to a job queue until they can begin execution. A job queue is a staging area, managed by the Sub system, where batch jobs wait in line for their turn at processing. A typical batch job submission would be a report program or a program compile. If such a program were run interactively, the D ...
... Are sent to a job queue until they can begin execution. A job queue is a staging area, managed by the Sub system, where batch jobs wait in line for their turn at processing. A typical batch job submission would be a report program or a program compile. If such a program were run interactively, the D ...
ppt
... creates a new address space (called the child) copies the parent’s address space into the child’s starts a new thread of control in the child’s address space parent and child are equivalent -- almost • in parent, fork() returns a non-zero integer • in child, fork() returns a zero. • difference allow ...
... creates a new address space (called the child) copies the parent’s address space into the child’s starts a new thread of control in the child’s address space parent and child are equivalent -- almost • in parent, fork() returns a non-zero integer • in child, fork() returns a zero. • difference allow ...
Introduction
... – Hides the messy details which must be performed – Presents user with a virtual machine, easier to use ...
... – Hides the messy details which must be performed – Presents user with a virtual machine, easier to use ...