Machine code instructions

Machine code instructions

1. Computers can ONLY understand machine code, 0s and 1s. Therefore, all instructions are written in machine code.

   • An instruction code is written in the form 0101 01 01001101
     • Op codes
       • The 1st four binary digits are the 'op code'. Op codes are operations the computer has been coded to do automatically.
         • For example, the code 0101 could make the computer copy a register to a memory location.
     • Registers
       • All computers have registers. They are a volatile area to store data.
         • Computers have different amounts of registers. If the register number is 2 digits long, the computer has only 4.
     • Operands
       • The operands are the data or memory location actually being used in the operation