The College of Saint Rose CSC 202 – Introduction to Programming David Goldschmidt, Ph.D.

 Hardware consists of five key subsystems: from Fluency with Information Technology, 4th edition by Lawrence Snyder, Addison-Wesley, 2010, ISBN

 Each instruction goes through this cycle: from Fluency with Information Technology, 4th edition by Lawrence Snyder, Addison-Wesley, 2010, ISBN

 We use ten symbols to count  Digits:  Computers use two symbols to count  Digits: 0 1 (why?)  What is the exact mechanism for counting?  How do we count from 1 to 20?

 The powers of 2 give us the decimal weights  Convert from binary to decimal:  in decimal is = 153  What about negative numbers? powers of decimal weights binary digits

 Use two’s complement representation for negative numbers  Convert from binary to decimal:  in decimal is = -103 powers of decimal weights binary digits

 Hexadecimal is base 16  It uses 16 digits: A B C D E F  Why use hex?  Binary numbers are too long  What’s 2BAD in decimal? decimalbinaryhexadecimal A B C D E F

 Represent printable and special characters  What about Unicode? from Fluency with Information Technology, 4th edition by Lawrence Snyder, Addison-Wesley, 2010, ISBN