EECS exam 2
Terms
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copy deck
- virtual memory
- by the use of paging more memory space is made
- Interactive processing
- OS that allows a program to be executed and also carry on a conversation with the user.
- Waiting
- =0 the process is full and needs to wait until the next job is free
- dispatcher
- controlls the execution of scheduled activities.
- Responsibilities of an Operating syustem (3)
- 1. controlls the overall operation of a computer 2.Provides means by which a user can retrieve files 3.provides the interace by which a user can request the execution of a program.
- the three truths for a deadlock to occur
- 1. there is competetion for nonshareable resources. 2. the resources are requested on a partial basis; thatis, having recieved some sources, a process will return later to request more. 3. once a resource has been allocated, it cannot be forcibly retrieved.
- Who assignes IP addresses
- ICANN inernet comrporation for Assigned Names and Numbers.
- WIMP
- Windows, Icons, Menus, Pointers
- Ready
- =1 the process is free and is ready to go.
- deadlock
- the condition in which two or more processes are blocked from progressing because each is waiting or a resource that is allocated to another.
- ethernet standards
- carrier sense, multiple acces with collision detection; CSMA-CD dictates that each message be broadcasst to all machines on the bus.
- bridge
- connects two busses but it does not pass all the messages across the connection
- GUI
- Graphical User Interface: the objects to be manipulated are represented pictorally on the monitor screen as icons.
- gateways
- the "point" where one network is linked to an internet; passage between the internet and the outside world.
- repeater
- a divice that passes signals back and forth between the two original bus devices without considering the menaing of signals.
- Network
- linked computer systems. computers are connected so that data can be transferred from machine to machine
- models of communication (2)
- P2P, Client\server
- why is security relevant to the OS'
- it helps reliability, a defect can cause system failures.
- bus
- machines all connected by a common communication line.
- virus'
- software that infects a computer by inserting itself into programs that already reside in the machine
- LAN
- Local area network: collection of computers in a single builting or buuilding complex
- Shell vs. Kernel
- one handles commmunication with the user, and the other handles the files and the memory.
- topology, phusical arrangement:
- the patterns in which machines are connected: Bus and Star.
- critical regions
- a sequence of instructions that should be executed by only one process at a time.
- Outside attacks:
- with use of a login information is safe; super user or administrators, auditioning software.
- Client\Server
- one makes requests of other processes; the other satisfies requests made by a client
- WAN
- wide area network: links machines over a greater distance.
- star
- one machine serves as central focal piont to which all others are connected
- switch
- a bridge with mulitple connections allowing it to connect several busses rather than njust the two.
- P2P
- peer to peer: the C\S model includes one process prviding servidvce to numerous others, the P2P includes instant messaging between users.
- registerars:
- each domain must be registered wiht ICANN-companies
- file descriptor
- the area where the memory stores the files
- evolution of shared computing:
- 1. 1940s the first computer model released, one job at a time was able to be processed. soon after, one user was able to use the computer by using batch prosscessing. then came interactive processing, then time sharing, multiprogramming, and load balancing.
- System software
- performs the infrastructure that application software requires.
- OS components
- 1. Shell 2. windows manager 3. kernel 4. decice drivers 5. memory managers 6. scheduler 7.dispatcher
- typers of malware (3)
- worms, virus' trojan horses
- Kernel
- the internal part of an OS system: contains basic functinos of a computer. consists of file manager, directories, etc.
- what is an interrupt
- every time an dispatcher awareds a time slice to a perocess, it initates a timer circut that will indicate the end by sending out a signal.
- semaphore
- permanently implemented flags
- what types of things are shared by networks?
- exchange messages, share resources that are scattered throughout the system.
- Parts of System software (2)
- 1. Operating System 2. Utility software
- domains
- the "region" of the Internet operated by a single authority such as a unviersity, club, company, or gov. agency.
- gtrojan hourse
- enters a computer system disguised as aderreable program. is imported by the user.
- batch processing
- the exection of multiple jobs by putting the jobs into one big batch and then executing them with interaction with the user.
- Application software
- consists of the programs for performing tasks particular to the machines utilization: i.e. spreadsheets, database systems, accounting systems, desktop publishing systems, program development software, games, etc.
- firewalls
- prevention technieques that filter traffic through a computer network
- the boot process
- a program called the boot strap is stored permanently on the computer, the program directly from the CPU is transferred form the operating system from mass storage into the main memory.
- directory\folder
- allows a user to organize their files to be a grouped bundle--a directory path.
- types of network devices (3)
- repeater, bridge, switch.
- Software Classifications (2)
- 1. Application software 2. system software
- what is a process
- is adynamic activity whose properties change as time progresses
- memory manager
- coordinates the machines use of memory: paging, pages, vurtual meomry.
- MAN
- metropolitan area network: intermediate size, spanning a local community
- scheduler
- schedules or allocates various resources to various proceses.
- how is a process different from a program
- is static set of directions and a process changes.
- encryption
- helps avoid password and information like such being transferred to different places.
- shell
- the part of an OS that handles the communication. Older shells communicate with users through text. Now they operate through GUI
- ownership closed vs. open
- closed is controlled by an entity (individual) and open is run by designes that are owned by public domains.
- types of attacks (2)
- outside and within
- Within attacks
- privledge levels
- Windows Manager
- Important component of GUI shells; allocates blocks of space on the screen windows) and keeps track of which application applies to which window.
- mutual exclusion
- the requierement that onely one process at a time is allowed to execute a critical region.
- wifi standards
- CSMA\CA(voidance)
- malware
- way a computer and its systsem can be attacked, malicious software.
- what is a process table?
- it keeps track of all the processes and the scheduler maintains the block of info in the main memory. the dispatcher manages it. Ready and waiting.
- File manager
- job is to coordinate the use of the machines mass storage facilities.
- internet
- networks must be connected in a way that builds a network of networks.
- worms
- autonomous program tha tenters a comptuer through a network and takes up residence in a computer and the ncopys and sends itself ot other computers.
- paging
- shifting memory left to right so that more memory space is available
- routers:
- special purpose computers used for forwarding messages
- utility software
- the collective name of all the software units. By using certain activities such as these, the program canbe scustomized t o the needs of the jparticular insallation more easily than if they were included in the OS.
- what is a network protocol?
- the rules by which activities are conducted.
- device driver
- software units that communicate with the controlers to carry out operations on the peripheral decices attached to the screen.
- the origin of Internet
- reserch projects in the 1960's. After finding a way to not lose incformation massly during local disaster.
- common operating systems (3)
- 1.Windows 2. LINUX (IBM) 3. UNIX (mac OS, solaris)
- geographic classifications of netowrks
- LAN, WAN, MAN