1. We know five .
3. The first computers were very big.
4. They were not very powerful, not very effective ant not very reliable.
5. The first generation employed vacuum tubes.
6. The example were ENIAC, BESM-1, MINSK-32. IBM-650.
7. The second generation was built in the late 1950's.
8. They used transistors in place of vacuum tubes.
9. They were IBM computers, BESM-4, 6, MINSK-32, M-220.
10. Their size was reduced.
11. The third generation computers began in the mid 1960's.
12. Their processors were made of integrated circuits.
13. These computers were IBM computers, ES computers, M-6000, NAIRI-3, SM-3.
14. The third generation introduced Operating System and Data Base Management System.
15. On Line system were widely developed.
16. The fourth generation started in the mill 1970's.
18. The example are IBM computers, ES computers, NAIRI-4, ELECTRONICA-60, ISKRA-1256.
19. The fifth generation is not yet built