Chapter 6 Powerpoint Flashcards
From the powerpoint
What is a naked machine
A machine that has no tools or programs to help the user
What type of tools or programs does a non- naked machine have
- Write instructions in binary
- Write data in binary
- Load instructions into memory one cell at a time
- Initiate program run
What were the problems with using a naked machine
It quickly became too difficult for humans to do. An interface had to be developed to hide the details and make the computer easier to build.
What is System software
A collection of programs to manage resources of the computer and to serve as an intermediary between user and hardware
What does system software create
A virtual machine or a virtual environment that the user sees.
What is an operating system considered
The single most important piece of software on the computer
What are the components of an operating system
The user interface Memory managers i/0 Systems Utilities Language services Information Managers Scheduler
What is the general function of system software
- Communicates with users
- Determines what they want
- Activates other system programs, applications, packages or user programs
Describe characteristics of language services within the system software
Language services support high level languages
Describe characteristics of memory managers within the system software
Memory managers allocate memory to programs
Describe characteristics of Information managers within the system software
Information managers organize mass storage
Describe characteristics of scheduler managers within the system software
Scheduler manages programs waiting to run
What are some utilities inside of system software
Tools including program libraries
What is a gui
A visual interface to the virtual machine including operating system and system programs and user programs.
What various devices do the I/O systems communicate with
Printers
Scanners
Keyboards
Mice
What are the 5 functions of a virtual machine
1) write program using text editor in high-level language
2) save program to folder
3) use translator to convert to binary
4) Use scheduler to load and run
5) use I/0 system to print results
What is the other name for low level programming language
Assembly language
What are the properties of assembly language
- Instructions map one-to-one to machine language
- Symbolic op codes (not binary)
- Symbolic addresses for instructions and data
- Pseudo-ops for data generation and more (data in human-friendly terms)
What are two advantages of assembly language over machine code
- Clarity, readability and maintainability
* Can be placed at different locations in memory
What are some examples of High level programming languages
Java, C++, Python
What are the advantages of high level programming languages over assembly language
- More powerful: One high level instruction may provide multiple machine instructions
- User oriented
- Not Machine Specific
- Use both natural language and mathematical notation
What is the assembly language process
- The source program (assembly language)
- Translated by the assembler to
- object program
- loader places in memory
- Hardware runs
- Results
Are comments in assembly language processed by the assembler
Comments are ignored by the assembler- they’re for human use
What does pseudo-op commands in the (assembly language) program do
Commands in the program directed to the assembler, not converted to machine instructions.
What is the function of the assembler in relation to assembly language
Converts symbolic op codes to binary equivalents
Converts symbolic labels to memory addresses
Performs pseudo-op
Writes object file containing machine instructions
What is the function of the loader in relation to the assembly language
Places instructions in memory
Triggers the hardware to run the program
How does assembler convert symbolic op codes to binary ones
Assembler maintains a table
Assembler looks up the symbolic op codes in the table and substitutes the binary analogue
Use binary search to optimize table lookups
When converting symbolic labels to memory addresses using assembly language how many passes does the assembler need
Assembler needs two passes - needs to look over assembly code two times
What occurs on the first pass of the assembler
- Keeps a count of how many instructions from the start
* Collects symbolic labels and add to symbol table along with location counter
What occurs on the second pass of the assembler
- Looks up and replace op codes
- Substitutes label references with location from symbol table
- Sets up .DATA pseudo-ops with location and binary value
- Writes instructions to object file
What are system commands
User instructions about what the computer should do
What are typical operating system commands
Load a program
Run a program
Save information in a file or a directory
Retrieve a file previously stored
List all the files for this user
Delete or rename a file
Print a file on a specified I/O device
Copy a file from one I/O device to another
Establish a network connection
Let user set or change a password
Tell how much memory or data storage is being used
Describe the function of a user interface in an operating system
User communicates with an operating system
Describe the text based functions of an operating system
System commands typed at a prompt in a terminal
Command language must be learned
Describe the GUI-based functions of an operating system
System commands by a visual /mouse interface
What is the built in system security and protection in an operating system
Permit only authorized access to resources. Uses operating system as a security guard
How is access to the operating systems resources regulated
Access is protected by usernames and passwords.
Superusers have more privileges
Encrypt data to increase security
What is another way that access is regulated in relation to folders and files
Both folders and files have authorization lists that allow a user to read a file, add new information to a file, change existing information and delete a file
What are the three permissions that a file or folder can have
Read
Write
Execute
What is the “receptionist” in an operating system
User interface management
What is the “security guard” in an operating system
Control of access to system and data files
What is the “dispatcher” in an operating system
Program scheduling activation
What is the “efficiency expert” in an operating system
Efficient resource allocation
What is the “traffic officer” in an operating system
Deadlock and error detection
When does a deadlock occur
A deadlock occurs when multiple programs are requesting the resources that each one is currently using.
What is an example of a safe use of resources
Ensuring that the computer doesn’t get stuck in deadlock
What is deadlock prevention
If you cannot get all of the resources then release all that you have and try again later
What is deadlock recovery
If no acknowledgement, send message again
Describe the historical development of operating systems: First Generation (nearly) “naked computer”
Programmer hand loaded programs
Describe the historical development of operating systems: Second Generation “batch operating systems”
Programmers gave programs to operators
Operators collected a “batch” of programs
Job control language: Instructions to OS
Describe the historical development of operating systems: Third Generation: Multiprogrammed operating systems
Multiple programs loaded at once
Switch between programs when I/O happens
Computer Security now required
Describe the historical development of operating systems: Third generation: Time-sharing system
Multiprogrammed, but users are on the system interactively.
Users need an illusion of sole access
Allocate run times in time slices - each program runs until I/O OR time runs out
Describe the historical development of operating systems: Fourth Generation: Network Operating System
Operating system supports all the same local services
Also supports services that access resources that are available over a network
What are some examples of services that access resources that are available over a network
Shared printer
Servers: email, data, web
Connections to the internet
What are real-time operating systems or embedded systems
Special-purpose computers in other equipment
Describe the historical development of operating systems: Fifth Generation
Multimedia interfaces
Parallel Processing System
Distributed Computing Environment
What is an example of multimedia interfaces
Integrate images, speech and video seamlessly
What is the function of a parallel processing system
Performs multimedia and to permit larger scale tasks
What is the function of distributed computing environments
Users don’t know where resources are stored
What is an example of Distributed Computing Environment
Cloud computing
