What was used before processor is invented?

Answer 1

Computing has been done many ways over the years:

1. Human computers using paper and pencil
2. Human computers using mechanical calculators
3. Human computers using analog calculating aids (e.g. slide rules)
4. Punch card unit record electromechanical accounting machines
5. Large automatic electromechanical analog computers (e.g. differential analyzer)
6. Plugboard programmed electronic punch card card calculators
7. Electromechanical paper tape programmed automatic calculators
8. Vacuum Tube electronic stored programmed computers
9. Magnetic amplifier electronic stored programmed computers
10. Transistorized electronic stored programmed computers
11. Small scale integration (10 transistors/IC) computers
12. Medium scale integration (100 transistors/IC) computers
13. Minicomputers
14. Large scale integration (1000 transistors/IC) computers
15. Single chip microprocessors (~4000 transistors/IC) <-------------------
16. Today we have single chip microprocessors with several 100 million transistors/IC!