Computers: Computer Language, Operating Systems. Book: Chapters 5, 8, 9
ITC QUIZ 1, due Sunday, October 12.
ITC ASSIGN 1, due Sunday, October 12.
- Human Requests to Computers
- Computer Translations
- Data Units of Information
- Bits, Bytes, Character encoding
- Operating Systems
- Humans have many ways of requesting info from computers:
- Hand activity (mouse, keyboard, touchscreen, etc.)
- Asking questions/making computer requests in human terms
- Computers do not speak human. They do not acgtually recognize the meaning of data at all. Computers just respond to electrical impulses, which is their Primer.
- Computers handle 2 decisions:
- Don't Act or Do Act, or No and Yes, or Off and On,
etc. Current on or off.
- Are there M&Ms? Yes, or No.
- However, computers need instructions to act if we want more than just a simple yes or no. This is considered to be an If-Then query.
- If there are M&Ms, then eat some. If there are not M&Ms, then do not eat some.
- But, what if you want more options? Let's face it, if everything was just yes and no, even basic processing gets boring and not very helpful. Therefore, we have the If-Then-Else query:
- If there are M&Ms, then eat some. If there are not M&Ms (say they have all been eaten), then (do something else) are there Reeses Pieces?
- If there are Reeses Pieces, then eat some. If there are not Reeses Pieces, then don't eat some.
- There are several additional decision structures that computers process by, but this gives you a starting point in basic computer logic.
- Computers do not comprehend or care what M&Ms are. M&Ms and every other request is just dumb input data for a computer and means nothing. The only thing that means something is Inactive or Active. But how does a computer take what we input and translate it so that it can process
and output a response to our requests?
- Computer applications just manipulate the contents of memory stores with the no/yes decisions. Note that this does not mean that the contents of those memory stores have a guarantee of accuracy.
Data Units of Information
- Bits are the smallect basic unit of information in computing.
- Bits use the binary numeral system, or base-2 numeral system, which represents numeric values using two symbols: 0 and 1.
- Bits are machine language, and a computer will represent that language as voltage levels - charge or no charge for memory stores.
- A bit can be only 0 or 1, don't act or do act, off or on, down or up, less voltage or more.
- 8-bit computer: CPUs that can access 8 bits of data in a single machine instruction, or the number of bits used to represent memory addresses.
- Humans count with 'finishing' numbers - real quantities of something that exists.
- Human numerical digits start with 1.
- Example: We don't tend to count Zero M&Ms - since Zero, to humans, means there are actually NO M&Ms. We start with M&Ms we see as existing
- 1, 5, 34, etc.
- However, Computers don't see Zero as a non-entity. Zero is more of a "bridge" number between positives and negatives which have equal existance.
- Computer numerical digits start with 0.
- Example: A computer's logic accepts that Inactivity is a state and that Activity is an equal state. For instance, the fact that there are Zero M&M's is a prompt for one type of action, while any other quantity or M&Ms prompts another type of action.
Building Complex Data Units
- If everything Humans need to be translated into computer terms stayed at 0 or 1, nothing would get done.
- The problem is, there is no "binary" number for 2, or 10, or 9999 M&Ms. Argh!!!
- In Decimal counting (0-9), after 9 we add a "1" to the left of the "0" to get 10, and do the same thing as the decimal numbers move up.
- This happens in Binary as well! 0=0, 1=1, 10=2, 11=3, 100=4, 101=5, 110=6, 111=7, etc.
- Here is a great simple explanation of binary math.
A Bit about Bits and Bytes
- A bit is a single binary digit, of 0 or 1. This is a useless
amount of information but when you group bits together and get 8 bits, this makes one byte.
- Combinations of 0s and 1s, or bytes, create sequences that computers can accept as input, process, release as output, and store.
- A byte is the number of bits used to encode a single character (visual symbol) of text in a computer. A single byte can have up to 256 different combinations of 1s and 0s (numbers 0-255).
- Typically information is broken up into bytes to be stored, calculated, or transmitted. This is why it is the basic addressable element in many computer architectures.
What does the computer DO?
Say that you type an "a" on your keyboard. The keyboard uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches. A computer keyboard distinguishes each physical key from every other and reports all key presses to the controlling software. They include control circuitry to convert key presses into key codes that the computer's electronics can understand. Here is a crude and simplified example of what is going on:
- You input the "a"
- The computer experiences a signal from the peripheral hardware.
- Is there a peripheral keyboard? YES.
- Did part of the keyboard experience input? YES.
- Did the "ESC" key of the keyboard experience the input? NO.
- Did the other keys before the letter "a" experience the input? NO.
- Did the key of the letter "a" experience the input? YES.
- And so on. Very, very fast. As computers became more efficient, the computer electronics could simply sense the specific letter key being pressed down, activating a bit of current, without needing to go through all other keys first.
Binary Blocks of Data
- The American Standard Code for Information Interchange ASCII chart is a character-encoding scheme originally based on the English alphabet (52 letters!!!).
- ASCII is 7-bit, and includes definitions for 128 characters. 33 are non-printing control characters, used for thinhgs like teletype characters for operators. 95 are printable characters or graphic symbols, including the space (which is considered an invisible graphic.
- ASCII codes represent text in computers, communications equipment, and other devices that use text.
- UTF-8 (UCS Transformation Format—8-bit) is a variable-width encoding that can represent every character in the Unicode character set, and was designed to be backward compatible with ASCII.
- Byte Me, in UTF-8 Binary Code = 01000010 01111001 01110100 01100101 00100000 01001101 01100101
- Introduction to number systems and binary
- Binary Translator: Check it out!!
Storage of information
A Byte = 8 bits of info, and can have 2 to the 8th variations, or 256 (2 to the 8th) codes of 0 and 1 variations.
- Common reference is actually, after the Byte, calculated by powers of 10, NOT powers of 2, though either can be used.
Kilobyte (kb) = 1000 bytes storage (10 to the 3rd), or 1024 bytes (2 to the 10th).
- Megabyte (mb) = 1000 killobytes (kb) storage or 1 million bytes (10 to the 6th), or 1,048,576 bytes (2 to the 20th).
- Gigabyte (gb) = 1000 megabytes (mb) storage or over 1 billion bytes (10 to the 9th)
- Terabyte (tb) = 1000 gigabytes (gb) storage or 1 trillion bytes (10 to the 9th).
- Yottabyte (yb) = 1 quadrillion bytes, or 10 to the 15th, or approximately 2 to the 80th. Whew!
- Operating Systems
- Windows 7 as example
- Windows 7 Accessories and Utilities
- An operating system (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs.
- The OS manages the computer's resources, such as the central processing unit, memory, disk drives, and printers
- It establishs a user interface (GUI) that allows applications to interact graphically with the OS and applications.
- It executes and provides services for applications software.
- The OS/GUI also allows users to interact with electronic devices using images rather than text commands
- Illustration of OS in hierarchy.
- PC Operating systems include Unix, Mac OS X, GNU/Linux, Google Chromium OS, Microsoft Windows, plus a variety of older ones.
- Tablets have even more OS software: Android, Blackberry, Apple iOS, Linux, Firefox, Windows, MS Surface, and older ones.
- In this class we will focus on the use of Windows 7, since it is what Seattle Central provides for this class.
- Windows 8 peek
- Explore Windows 7 Features
- Operating system/interface
- Built-in programs/utilities
- Services: background programs/processes that provide support to other programs,
often through Internet connectivity.
- Desktop: user interface
- Windows explorer: file locations and search
- Quickbar: shortcuts and messages
Windows 7 comes with several built-in tools to help users see their computer's status/hardware, streamline their computer's operations, loading speed, memory management, etc.
- Information: System Info, Task Manager, Device Manager, various monitoring tools/logs
- Speed/Clean-up: Services, Registry (clean-up)
- Hard Drive: Defrag, Disk Cleanup, Install/Uninstall Programs
- Memory Management: Disk Clean-up
- Problems: Troubleshooters, File Recovery, System Restore, Registry tweaking
Windows comes with various security protection options. Many users prefer another package like McAfee, Norton, Kaspersky, AVG, etc,
- Action Center
- Windows Defender
- Optional gadgets
- Press and click: link to programs and tools
- Personalization: Desktop background, Themes, Sounds
Programs access - Start Button
- Start button
- Shortcuts vs real links
- Start Button Area recent files and programs
Built-in programs - Start Button
- Accessories: calculator, notepad, paint, etc.
- Administrative Services: performance, system issues and tools
- Control Panel: links to manage functions like devices, preferences, passwords, and more.
- Bottom of screen
- View program shortcuts
- View/hide utilities
- Open programs thumbnail view
Help Section - Start Button
- Help and Support at Start button
- Blue icon with question mark
- Online vs Offline
Closing Windows 7/the computer - Start Button
- Shut Down
- Alt Tab: shift between open windows
- Ctrl C: Copy
- Ctrl V: Paste
- Ctrl W: Close Window
- Save fave program shortcuts on taskbar
- DO NOT save program files on desktop
- Windows Explorer/Computer
- File Management
- Good practices
Windows Explorer - Start Button
- Choose Computer, or Accessories/Windows Explorer
- Lists files and program locations
- Sections: Favorites, Libraries, Homegroup, Computer, Network
- Folders: contain one or more files in organized fashion
- Files: documents and media, like notes, spreadsheets, video clips, programs
- Program files: active files that execute an action (open a program)
- Static/Info files: Files that hold information
- NOTE: Opening static files actually executes the program the file was created
- USB Flash drive file structure
- A file name and icon is an original of the file or program.
- A shortcut is a copy of the original file icon that you can move elsewhere,
open, and delete.
- A shortcut icon shows a tiny arrow on it.
- DO NOT delete a program file.
- DO NOT delete original document or media files unless you are sure.
- Deleting a shortcut icon does not delete the program.
- Warning messages.
- Tree/outline format of folders and files.
- Hierarchical from outside to inside.
Non Windows systems
- Mac maintenance/cleanup/fixes can include: force-quit stuck programs, viewing the activity monitor, Apple Utilities, disk management, software updates, booting into safe mode, running malware and virus checks, etc.
- Tablet maintenance/cleanup/fixes can include: keeping it charged and clean, deleting unused applications, freeing up RAM, full restarts, have updated apps, factory reset, using virus and malware protection, and rooting.
- Phone maintenance/cleanup/fixes can include: Using a web/downloadable troubleshooting service from the carrier, doing a master reset, remove/replace battery, update phone software, make sure call forwarding is set properly, and eliminate some 3rd-party apps.
Organizing your files
- Name folder by topic
- Name files by purpose
- Use simple names
- Use consistent names
- If making copy of files or folders, add a, 01, 02 afterwards
- Example: SCHOOL/ITC102/notes042014.docx
- ITC QUIZ 1: Due Sunday, October 12.
- ITC ASSIGN 1: Due Sunday, October 12.
- ITC EXTRA 1: Word Search, 2 points. Print out, have fun, turn in the print-out before Wednesday, October 22.
- ITC EXTRA 2: Byte Me. Your Name in Binary, 1 point. Translate your name into binary, and UPLOAD it on the CANVAS tool, due Wednesday, October 29. Example: Lisa Bothell = 01001100 01101001 01110011 01100001 00100000 01000010 01101111 01110100 01101000 01100101 01101100 01101100