Computing Fundamenatls CMSC 201 Computer Science I Penny Rheingans University of Maryland Baltimore County (with inspiration from previous 201 instructors and the creators of UMBC

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Computing FundamenatlsCMSC 201Computer Science
I Penny RheingansUniversity of Maryland
Baltimore County(with inspiration from previous
201 instructors and the creators of UMBCs CMSC
101 and HMCs CS5)
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Learning Objectives

• To have a very basic overview of the components
  of a computer system
• To understand how data is represented and stored
  in memory
• To be aware of elements of the UMBC computing
  environment

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Computing Systems

• Hardware Components
• Central Processing Unit (CPU)
• Auxiliary Processors (GPU, etc)
• Memory
• Bus
• Secondary Storage (hard disk, flash drive, ...)
• Network Connection
• External Devices keyboard, monitor, printer
• Software Components
• Operating System Linux, MacOS, Windows, etc
• Applications

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Binary Representation

• All information is store in a binary
  representation (ie, its all 1s and 0s) code,
  text, images, sounds
• For each type of item/object, there are specific
  formats that define who to represent that thing
  (character, digit, sound, image, etc) in binary
• But why use binary?

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But why binary ?
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Place Value Notation
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Converting from Binary

• What are the decimal equivalents of
• 101
• 1111
• 10 0000
• 10 1010

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Converting to Binary

• What are the binary equivalents of
• 9
• 27
• 68
• 1000

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UMBC Computing Environment

• We will develop our programs using UMBCs GL
  system
• GL is running the Linux Operating System
• GUI interface Graphical user interface
• Command-Line Interface When you connect to GL
  using SSH
• Lab 1 will walk you through using the UMBC
  computing environment

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How do I connect to GL?

• Assuming you have Internet access, use SSH
• Windows
• Download Putty (Lab has a video about this)
• Hostname gl.umbc.edu
• Make sure you pick SSH
• Put in username and password
• Mac
• SSH client already installed
• Go to the Application folder and select Utilities
• Open up a terminal Window
• Type ssh -l username gl.umbc.edu
• Put in your password

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Linux Commands

• See
• http//www.csee.umbc.edu/resources/computer-scienc
  e-help-center/Resources
• For now, lets just learn
• ls list
• Display the files and directories in your
  current directory
• cd change directory
• Directory is another word for folder
• .. parent directory
• . current directory
• mkdir- make directory
• Note Commands are case-sensitive

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Directories

• Can contain files and other directories
  (calledsubdirectories)

/afs/umbc.edu/users/first/second/username/home
201
myOtherClass

• When you log into Gl, you will be in your home
  directory
• use the cd command to go to subdirectories

lab1
HW1
lab1.py
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emacs

• Reference
• http//www.csee.umbc.edu/summary-of-basic-emacs-co
  mmands/
• emacs a text editor
• We will generally use emacs to write our python
  code
• To open a file that you want to call example.txt
  (replace example.txt with your file name)
• Type emacs example.txt
• To save a file
• CTRL X and CTRL C
• To reopen the file
• Type emacs example.txt
• To remove the file
• Type rm example.txt