What is a Computer

• A computer is a device that can store and process data
• First modern computer was made in 1945
• It was called ENIAC, which used vacuum tubes
• ENIAC only worked for 15 minutes at a time

How do Computers Store Data

• Data is stored in binary bits, 0 & 1
• 0 is off, 1 is on, 1 bit has 2 patterns
• 8 bits is 1 bytes
• 1 byte can store any number between 0-255

Binary-Decimal Conversion

• Binary and Decimal are positional number systems
• Decimal means Base-10, made with digits 1-9
• Binary means Base-2, made with digits 1 & 2

Binary to Decimal

$1101_2 = 13_{10}$

Decimal to Binary

$15_{10} = 1111_2$