A Bit About Bits

Computer's Information is Digital

• Bit/binary digit
• the smallest unit of information
• can have one of two value: 1 or 0
• can represent numbers, codes, or instructions
• byte: a collection of 8 bits
• using two symbols all numbers represented on a calculator as well as performing arithmetic

0 represents the off signals
1 represents the on signals

Decimal numbers- 0,1, 2, 3, 4, 5, 6, 7, 8, 9

the binary number system works the same way as the decimal number system, but with two digits instead of ten.

• so we add a second column twice the value of the column before
• ex. 10, 11, 100, 101, 110 , 111, 1000...

Binary uses two digits so each column is worth twice the one before , with this and expanded notation we can convert from binary to decimal system. in the binary system, the columns are worth 1, 2, 4, 8, 32, 64, 128, 256, etc. to convert from binary to decimal write as expanded notation

Bits as Numbers

• binary number system
• binary denotes all numbers with combinations of two digits
• decimal numbers are automatically converted into binary numbers and vice versa
• binary number processing is completely hidden from the
  

Bits as Codes

• ASCII Code
  
  
  • American Standard Code for Information Interchange
  • The most widely used code
• Unicode
• A coding scheme that supports 65,000 unique characters

Bits as Instructions in Programs

• Programs are stored as collections of bits
• Instructions are represented in binary notation through use of codes

Bits, Bytes, and Buzzwords

• Byte= 8 bits
• Kilobyte (KB)= 1 thousand bytes
• Megabyte(MB)= 1 million bytes
• Gigabytes(GB)= 1 billion bytes
• Terabytes (TB)=   1 trillion bytes