Computing Components 01/26/11

Announcements & Reminders Programs 1 due Friday, 9/2/11 What is my late policy? Proxy Codes for Labs  You should be able to get in now, if you have an ID with a gold bar

Change Your Password The command is: passwd  In the lab first do : ssh -Y onyx You will have to see me to change it, if you forget it.  Change it to something you can remember.

Computing Machines

Today Parts of a Computer Instruction Cycle More linux

Parts of Computer

CPU Central Processing Unit  “Brain” of computer Has  Control Unit Decodes instructions Sends signals to rest of System  ALU, Arithmetic and Logic Unit Add, Subtract, Compare  Registers High speed memory locations inside CPU

Memory Integrated circuit chips Used to store data and instructions

Memory Stored as ones and zeroes Bit – binary digit Byte – eight bits, a character Word – 16, 32, 64 bits.

Memory Address  Binary number that tells where something is stored. Contents  Data contained at that address.

Secondary Storage What happens to data in memory when you turn off the machine? What are examples of long term storage devices  Thumb drive  Hard Drive  Tapes

Input/Output Input  Allows information to be sent to the computer  Keyboard, Scanner, Mouse, Microphone Output  Allows user to receive information from the computer.  Monitor, Printer, Speaker

Relationship of Parts Sketch of System Instruction Cycle

How does CPU know what to do? Software – programs. Operating System  Controls interaction of hardware.  e.g. print, copy Application Software  Solve real world problem  e.g. add interest to a bank account

Languages Machine code  Binary code  Specific to CPU Assembly Language  Mnemonic code High Level Language  Machine independent  C/C++, Java, FORTRAN

Compiler Translates H.L. to M.L. Source File --> Object File C++ Text File --> Binary

Other Software Linker  Resolves cross references, e.g.  Creates executable file Loader  Copies executable file to memory  Starts execution

Quiz Monday, 1/31/11 On your own  p. 24 #1-8, 13, 14, 16  Odd answers in text Define  Memory address  Memory contents  Machine language

Reading Read Chapter 2

More Linux Will cover more as semester progresses