BCD

Binary coded decimal is a binary representation of decimal numbers where each nibble (4 bits) in a word represents a separate decimal digit.

For example, in BCD, the value 128 would be represented in a 16-bit value as:

Binary:    0 0 0 0     0 0 0 1      0 0 1 0     1 0 0 0
Decimal:         0           1            2           8

(Note that, in traditional binary integer representation, the same binary number represents the decimal value 296).