What are the disadvantages of the fourth generation of computer?

The
fourth generation computers are characterized by microprocessors, which contain a large number
of integrated circuits (IC). The first microprocessor chip, Intel 4004 chip, was developed in
1971. Very large scale integration (VLSI) allowed a large number of ICs to be squeezed onto a
single chip, resulting in microprocessors that power these computer and a large number of other
devices. The computers that we use today are all fourth generation systems.

The disadvantage of these computers is that the microprocessor design and fabrication
is very complex and requires expensive setup and highly skilled staff for manufacturing. This
has limited the design and fabrication to very few companies (Intel, AMD, etc.) and made
everyone dependent on them. Another disadvantage is susceptibility to large-scale attack on
networked system. Smaller computers meant that they could be networked, paving the way for
internet. This also leaves the possibility of a virus attack on the entire system, making
everyone vulnerable. 

Hope this helps.