- Computer Generation -1(1941-1956):
 |
| IBM 650Magnetic Drum Calculator |
- Use of Vacuum tubes and magnetic drums (for data storage).
- Larger AC were needed.
- Programming in Mechanical Language.
- High Electricity Consumption .
- Big & Clumsy.
- Computer Generation -2(1956-1963):
 |
| Computer G-2 |
- The main components: Transistor.
- Higher processing speed.
- Core Memory was developed.
- Smaller size.
- Using a high level programming language..
- First Operating System was developed.
