
Students Guide to Information
Technology
A-
AND gate
NOT gate
Figure 2.5 Symbols used for
AND,
OR
and
NOT gates
AND I»· Units
Figure
2.6
A
half-adder gate
above. It is circuits like these that enable chips to perform calculations
and therefore to be used in calculators, cars, cameras, and computers.
Microprocessors and computers
Any suitable type of switch can be used to build up the logic gate
circuits used in the central processing units (CPUs) of computers.
However, because many thousands are required to construct
circuits for even the simplest computer, it is important that they
should be small, reliable, cheap, and consume little power