Source : Free On-Line Dictionary of Computing

third generation computer
     
         A computer built with small-scale integration
        {integrated circuits}, designed after the mid-1960s.
     
        Third generation computers use {semiconductor} memories in
        addition to, and later instead of, {ferrite core memory}.  The
        two main types of semiconductor memory are {Read-Only Memory}
        (ROM) and read-and-write memories called {Random Access
        Memory} (RAM).
     
        A technique called {microprogramming} became widespread and
        simplified the design of the {CPU}s and increased their
        flexibility.  This also made possible the development of
        {operating systems} as {software} rather than as hard-wiring.
     
        A variety of techniques for improving processing efficiency
        were invented, such as {pipelining}, (parallel operation of
        {functional units} processing a single instruction), and
        {multiprocessing} (concurrent execution of multiple programs).
     
        As the execution of a program requires that program to be in
        memory, the concurrent running of several programs requires
        that all programs be in memory simultaneously.  Thus the
        development of techniques for concurrent processing was
        matched by the development of {memory management} techniques
        such as {dynamic memory allocation}, {virtual memory}, and
        {paging}, as well as {compilers} producing {relocatable code}.
     
        The {LILLIAC IV} is an example of a third generation computer.
     
        The CTSS ({Compatible Time-Sharing System}) was developed at
        {MIT} in the early 1960s and had a considerable influence on
        the design of subsequent timesharing operating systems.
     
        An interesting contrasting development in this generation was
        the start of mass production of small low-cost
        "{minicomputers}".