1-12
Here, as in the decimal system, the MSD is the digit that will have the most effect on the number; the
LSD is the digit that will have the least effect on the number.
The two numerals of the binary system (1 and 0) can easily be represented by many electrical or
electronic devices. For example, 12 may be indicated when a device is active (on), and 02 may be
indicated when a device is nonactive (off).
Figure 1-1. —Binary Example
Look at the preceding figure. It illustrates a very simple binary counting device. Notice that 12 is
indicated by a lighted lamp and 02 is indicated by an unlighted lamp. The reverse will work equally well.
The unlighted state of the lamp can be used to represent a binary 1 condition, and the lighted state can
represent the binary 0 condition. Both methods are used in digital computer applications. Many other
devices are used to represent binary conditions. They include switches, relays, diodes, transistors, and
integrated circuits (ICs).
Addition of Binary Numbers
Addition of binary numbers is basically the same as addition of decimal numbers. Each system has
an augend, an addend, a sum, and carries. The following example will refresh your memory:
Since only two symbols, 0 and 1, are used with the binary system, only four combinations of
addition are possible.
0 + 0
1 + 0
0 + 1
1 + 1
