1_1_Computer system

1_1_Computer system

1. OS

   • A operating system manages a computer system. It manages resources
     • manages peripherals
     • manages printing using spooling
     • manages backing store( check that data can be retrieved)
     • file compression
     • disk de-fragmentation
     • manages memory and processes
     • manages security

2. Libraries

   • A library is a collection of commonly used private functions and subprograms
   • functions and subprograms can be called from with in your program at any time
   • They save time as programmers can just use a library
   • programs use less code

3. Ide

   • editor: Allows a programmer to enter , Format and edit source code
   • Compiler: Converts source code to machine code
   • Interpreter: converts each line of source code into machine code and exexutes
   • Linker: Allows code to be linked together
   • loader; A program which allows previously compiled code into memory
   • Debugger: A program which helps locate, identify and rectify errors in a program
   • Debugger; a program which helps locate and identify errors in a program
   • Trace; A facility which displays the order in which the lines of a program and executed, and possibly the values of variables as the program is run
   • Break point: A facility which displays the order in which the lines of a program on a specific line of code, allowing the programmer to compare the values of variables against expected values.
   • Variable watch: displays and "watches" the current value of any variable
   • Memory Inspector: displays what's in memory
   • error diagnostic: Displays error messages

4. Disk Organization

   • formatting is the process of preparing the disk for use
   • compression: is the process of making a file smaller. there is software and hardware compression both have advantages and disadvantages