The instruction set of different computers differ from each other mostly in the way the operands are determined from the address and mode fields.
Most computer instructions can be classified into three categories:
1. Data transfer instructions
2. Data manipulation instructions
3. Program control instructions
Data transfer instructions cause transfer of data from one location to another without changing the binary information content.
Data manipulation instructions are those that perform arithmetic, logic, and shift operations.
Program control instructions provide decision-making capabilities and change the path taken by the program when executed in the computer.
- Data transfer instructions move data from one place in the computer to another without changing the data content. The most common transfers are between memory and processor registers, between processor registers and input or output, and between the processor registers themselves.