• The size of computers was very large

• The size of computers was very large.
• Computers depended on only machine language.
• The computers heated very soon.
2) 2nd Generation (1956-1963).
This generation using the transistors for replacing vacuum tubes, the transistors initially created in 1947 at Bell Labs. Transistors weren’t used altogether in PCs until the point that the finish of the 1950s.In any case they were superior to anything the vacuum tubes, making PCs smaller, quicker, less expensive and less substantial on power use. More dependable and more vitality effective, than original forerunners, the language evolved from cryptic binary language to symbolic (Assembly) languages. Regardless they depended on punched cards for input and printouts for output.