created: 06/25/96; 2nd edition: 05/13/01; little bitty changes: 09/01/01

# CHAPTER 3 — Bits and Bit Patterns

Computers represent data and instructions with patterns of bits. You must become familiar with bit patterns! This chapter will help you. It discusses the fundamentals of bit patterns.

Chapter Topics:

> - Patterns of bits.
> - The number of patterns that can be formed for N bits.
> - How to systematically list all the patterns for N bits.
> - Multiplying powers of two.
> - Bytes, kilobytes, megabytes, and gigabytes.
> - Names for four-bit patterns.
> - Hexadecimal names for bit patterns.
> - Octal names for bit patterns.

In most computer documentation, 8 contiguous bits are called a byte. A bit holds a zero or a one, possibly representing the on/off condition of a switch.

### QUESTION 1:

How many patterns can be formed with a single bit?