Revision December 2016

Revision December 2016

1. Binary, hexadecimal and denary values

   • To convert denary values into hexadecimal you will need to first turn the denary value into the binary nibbles, after you've done that you need to turn each nibble into a hexadecimal value.
   • to conver binary to hexadecimal you need toturn the binary value into 2 nibbles, after that is done you will need to find the value of both nibbles (Don't forget to find the correct value by changing 128, 64, 32 and 16 into 8, 4, 2, 1.) then just join up the 2 values for example 9 and b will be 9b.
   • To convert hexadecimal into denary you just reverse the process that I have explained above

2. Opcodes and Operands

   • Opcode is a single instruction which was sent to the CPU to be executed
     • Opcode is written in machine language because it is not for human to understand but for the computer to understand
       • Opcode is short for operation code.
   • The operand is manipulated by the Opcode because Operand is the data that is being used.

3. IP and MAC addresses

   • MAC addresses
     • A MAC address is a unique identifier which each network has to help each node communicate with each other
     • MAC is short for Media Access Control
   • IP addresses
     • A IP address is a unique string of numbers separated by full stops to identify each node.

4. The charasteristics of an assembler, interptreter and an compiler

   • All of these translate high level code into machine code except an assembler because that translates assembly language into machine code
   • A Compiler translates the whole code at once, the same thing is with an assembler but an assembler is a different type of a compiler because it translates different code which is assembly code whereas the compiler translates high level code but both translate their codes into machine code.
   • The interpreter translates high level code into machine code line by line unlike the assembler or compiler
   • D.I.C.E

5. Formatting and defragmentation

   • Defragmention is a process which is used by the system to reduce a amount of fragmentation in files. This is done to provide more space in the file system
   • Formatting is a command which is used to accomplish many tasks. Formatting is mostly used when the Disk and file system needs to be changed, it also tells if each cluster is good or bad.
     • Formatting cannot do anything with data area itself leaving it untouchedwhen the disk is formatted