COP4600 Quiz 1

What is an Operating System?

A program that acts as an intermediary between a user of a computer and the computer hardware

Operating system

Controls and coordinates use of hardware among various applications and users

interrupt

Device controller informs CPU that it has finished its operation by causing an _________ .

tracks

Disk surface is logically divided into _______

device driver

Each device controller type has an operating system _________ to manage it

Operating system goals

Execute user programs and make solving user problems easier

Computer system can be divided into four components:

Hardware, Operating system, Application programs, Users

interrupt vector

Interrupt transfers control to the interrupt service routine generally, through the _____________, which contains the addresses of all the service routines

Operating system goals

Make the computer system convenient to use

bus

One or more CPUs, device controllers connect through common ________ providing access to shared memory

Users

People, machines, other computers

Device Driver

Provides uniform interface between controller and kernel

Bootstrap program

ROMBIOS - read only memory Basic Input Output System.

embedded computers

Run primarily without user intervention

nonvolatile

Secondary storage - extension of main memory that provides large _________ storage capacity

Speed, Cost, Volatility

Storage systems organized in hierarchy

After I/O starts, control returns to user program without waiting for I/O completion

System call, Device-status table, OS indexes into I/O device table to determine device status and to modify table entry to include interrupt

kernel

The one program running at all times on the computer

resource allocator and control program

This is what operating systems are and make efficient use of HW and managing execution of user programs

sectors

Tracks are divided into this:

Operating system goals

Use the computer hardware in an efficient manner

middleware

a set of software frameworks that provide additional services to application developers such as databases, multimedia, graphics

EEPROM

ability to update the bios and make changes

application program

all programs not associated with the operating system

smartphones and tablets

are resource poor, optimized for usability and battery life

Device-status table

contains entry for each I/O device indicating its type, address, and state

disk controller

controller determines the logical interaction between the device and the computer

What do users want?

convenience, ease of use and good performance

Caching

copying information into faster storage system; main memory can be viewed as a cache for secondary storage

CMOS

date and time/hardware configuration info

Application programs

define the ways in which the system resources are used to solve the computing problems of the users. Word processors, compilers, web browsers, database systems, video games

BIOS

f12 or delete to make changes to the software: boot order

Non-volatile memory (NVM)

faster than hard disks, nonvolatile •Various technologies Becoming more popular as capacity and performance increases, price drops

I/O

from the device to local buffer of controller

How does CPU move data?

from/to main memory to/from local buffers

workstations

have dedicated resources but frequently use shared resources from servers

CPU

instruction Register, PC -program counter

An operating system is:

interrupt driven

device controller

is in charge of a particular device type. has a local buffer

Main memory

only large storage media that the CPU can access directly. •Random access •Typically volatile •Typically random-access memory in the form of Dynamic Random-access Memory (DRAM)

POST

power on self test

Hardware

provides basic computing resources. CPU, memory, I/O devices

System call

request to the OS to allow user to wait for I/O completion

What do user's don't care about?

resource utilization

Hard Disk Drives (HDD)

rigid metal or glass platters covered with magnetic recording material

system program

ships with the operating system, but not part of the kernel

trap or exception

software-generated interrupt caused either by an error or a user request

ROM

storage memory that could be permanent

The operating system preserves the state of the CPU by

storing the registers and the program counter

Separate segments of code determine:

what action should be taken for each type of interrupt

Two methods for handling I/O

•After I/O starts, control returns to user program only upon I/O completion •After I/O starts, control returns to user program without waiting for I/O completion

After I/O starts, control returns to user program only upon I/O completion

•Wait instruction idles the CPU until the next interrupt •Wait loop (contention for memory access) •At most one I/O request is outstanding at a time, no simultaneous I/O processing