Second Generation (1954-1962)
The second generation saw various significant developments at every level of computer system design, from technology used to build the basic circuits to programming languages used to write scientific applications.
Electronic switches in this age were based on discrete transistor and technology with a switching time of about 0.3 microseconds. The first machines that was built with this technology include TX-0at MIT's Lincoln Laboratory and TRADIC at Bell Laboratories in 1954. Memory technology was based on magnetic cores that could be accessed in random order, in oppose to mercury delay lines, in which data was stored as acoustic wave which passed sequentially through the medium and could be accessed only when data moved by the I/O interface.