Operating Systems Flashcards
What are the 3 purposes of Operating Systems?
1) Manage System Resources
2) Create a Common Platform for software applications
3) Access Input/output devices on behalf of software applications
What are the 6 main tasks of OS’s?
1) Process Management
2) Memory Management
3) File System Management
4) Device Management
5) Application Interface
6) User Interface
What is Prfocess Management?
OS gives commands to CPU
What is Memory Management?
OS puts data inside RAM
What is File System Management?
How data is stored on our long term devices
What is Device Management?
Managing Input/output devices
What is Application Interface?
Common look and feel of software from outside vendors (mostly applicable to programmers)
What is User Interface?
How we (users) interact with Operating System
What are the two ways to interface with OS’s ?
1) GUI “Gooey” - Graphical User Interface, mouse driven interaction
2) Command Line - Strictly keyboard driven interaction
What are the 4 families of OS’s?
1) Real Time OS
2) Single-User, Single-Task
3) Single-User, Multi-Task
4) Multi-User, Multi-task
What is Real Time OS?
Designed for one task and do it over and over again; custom written for specific reason
(mostly found in factories, utilities, etc)
What is Single-User, Single-Task?
Allow for only ONE logged on user at a time, user can ONLY do one thing at a time
(dos, no background programs running)
What is Single-User, Multi-Task?
Only one user at a time, but can run multiple programs at once
(most Commonly used by us)
What is Multi-User, Multi-Task?
More than one user, actively using at once, multiple activities going on at once
(most often in servers, websites, etc)
**What is “Partitioning”?
taking a hard drive and making it into multiple storage areas;
Making one Physical Drive into multiple Logical drives. Each Partition is assigned a letter
(ie. “E drive”)
What is step 1 of the start up sequence?
The BIOS invokes the Power On Self Test (POST), checks the system hardware to make sure everything is working properly
**What is the POST?
Power On Self Test - CPU, RAM and Keyboard must be in place in order to start up, all of the info initially goes into RAM
What is step 2 of the start up sequence?
After POST, the BIOS-CMOS executes various instructions including looking for boot devices from which to boot:
1) Recalls all saved settings
2) Recalls date and time
3) Looks for boot devices (OS to load)
- you can manipulate boot order in BIOS if you need to
What is step 2.5 in the start up sequence?
The BIOS system check info goes into RAM
What is step 3 of the start up sequence?
Once the bootable drive is identified, the first part of the OS to activate is the “Boot Strap Loader”
**What is the “Boot Strap Loader”?
The beginning code for the OS, all BSL’s for OS’s are located in the same exact set/location on the hard drive, CD, thumb drive or any device it is started on
What is step 4 of the start up sequence?
Once the OS BSL has fully executed, the OS itself takes over the remainder of the boot-up process
What is a “graceful” shut down?
shutting the OS down the way it was intended to be shut down
What is an “un-graceful” shut down?
opposite of graceful, you just STOP the computer
What is the MAIN function of an Operating System?
It runs your hardware
What is a “Process”?
Any running program on your computer
