CS 121 Lecture Notes - Lecture 4: Binary Number

• School: Pace University
• Department: Computer Science
• Course: CS 121
• Professor: Shan

Document Summary

Binary values & digital electronic signals go hand in hand: they improve the ability to transmit info reliably along a wire. An analog signal has continuously varying voltage w/ infinitely many states, but a digital signal is discrete, which means the voltage changes dramatically between one extreme (+5 volts) & the other (-5 volts). At any point, the voltage of a digital signal is considered to be either (cid:498)high(cid:499), which represents a binary (cid:883), or (cid:498)low(cid:499), which represents a binary (cid:882). A digital signal degrades just as an analog signal does, but b/c the digital signal is originally at one of two extremes, it can be reinforced before any info is lost. The voltage can change slightly from its original value, but it can still be interpreted correctly as either high or low. The number of bits reuse in any given situation determines the number of unique items we can represent.