CH 1 A Digital Basics What is the

CH 1 A Digital Basics

What is the Digital Revolution? • The digital revolution is an ongoing process of social, political, and economic change brought about by digital technology, such as microchips, computers, and the Internet. • Digital – data represented by numbers (such as 1 s and 0 s) • Digit refers to a numeral less than 10. • Digital innovations challenge the status quo and require societies to make adjustments to traditions, lifestyles, and legislation. • EX: Data can be easily duplicated. Digital copies are essentially indistinguishable from originals, which has created new possibilities for content distribution on platforms such as i. Tunes and Netflix.

What is Data? • Data refers to the symbols that represent people, events, things, and ideas. Data can be a name, a number, the colors in a photograph, or the notes in a musical composition. • Data becomes information when it is presented in a format that people can understand use. • As a general rule, (technically speaking) data is used by machines, such as computers; information is used by humans. • Data representation refers to the form in which data is stored, processed, and transmitted.

What is the difference between analog and digital data? • Digital Data is text, numbers, graphics, sound, and video that have been converted into discrete digits such as 0 s and 1 s • EXs: traditional light switch, digital clock • Analog Data is represented using an infinite scale of values • EX: dimmer light switch, your car’s speedometer

How is digital data stored? • Digital data is typically stored in files. • A file is a named collection of data that exists on a storage medium, such as a hard disk, CD, DVD, or flash drive. • Can contain data for a term paper, Web page, email message, or music video. • Every file has a unique name, such as Thriller. mp 3. • A file name extension, such as. mp 3, can be appended to the end of the file name after a period. This extension indicates the file format; the type of data in the file and the way it is encoded. • . zip is a compressed file • . doc and. docx are Microsoft Word • . pdf is adobe acrobat

How does digital data work? • Digitalization is the process of converting information, such as text, numbers, photos, or music, into digital data that can be manipulated by electronic devices • Computers use 1 s and 0 s to represent digital data. The 1 s and 0 s are referred to as binary digits. • Binary - relating to, composed of, or involving two things. FOR EXAMPLE: Imagine that you want to send a message by flashing a light. Your light switch offers two states: on and off. You can use sequences of ons and offs to represent various letters of the alphabet. BUT to write down the representation for each letter DIGITALLY, you can use 0 s and 1 s. • The 0 s represent the off state of your light switch; the 1 s indicate the on state • For example, the sequence on on off would be written as 1100, and you might decide that sequence represents the letter A.

Programmers write computer code and this is converted by a translator into binary instructions that the processor can execute.

Are there other ways digital data is represented? Digital devices are electronic and so you can envision bits flowing within these devices as pulses of light. But digital signals can take many forms, as shown in the figure:

NEXT YR: Cut out the code. org binary activity? HOW DO WE MAKE IT SHORTER?

Code. Org Sending Binary Messages Activity • Prompt: Imagine that you and your friend have not been able to communicate for the entire summer, and you have a chance to ask her one binary question that she will answer. • Brainstorm: What binary question do you want to ask? • How could you answer it? • Answering a binary question is easy when we speak to each other, but it becomes more difficult when we are separated. • Today we will focus on how a binary message can be sent over a distance. You will build the device that sends them. A binary question is a question to which there are only two possible answers. EX: the question "Do we have a quiz today? " is a binary question, as there are only two possible responses, "yes" and "no. " Typically we think of binary questions as ones that can be answered "yes/no, " "true/false, " etc. BUT many either/or type questions have binary responses as well, such as in “Which do you prefer: Coke or Pepsi? ” or “Country music or hip hop? ”

5 t o g e v ’ u Yo ! O G ! s e t u n mi

Share out with the class • What question did you start with? • What were the two possible answers and what device did you build to answer those? • How did you change your device for 4 answers and 8 answers (and what were those answers? ) • Could you use this method for a question with more possible answers?

Fill out rubric. Don’t forget to do the questions on the back!

What is the difference between “numeric data” and “character” data?

What is the difference between “numeric data” and “character” data? Numeric Data consists of numbers that can be used in arithmetic operations. EX: your annual income your age Digital devices represent numeric data using the binary number system

How do digital devices represent numbers? • Digital devices represent numeric data using the binary number system • Binary number system allows digital devices to represent virtually any number simply by using 0 s and 1 s. Digital devices can then perform calculations using these numbers. The ability to perform rapid and accurate calculations was the key feature of the first computers, and it now provides the foundation for online banking and ecommerce.

The Binary Number System PPT

How do digital devices represent character data? Character data (aka “text”) is composed of letters, symbols, and numerals that are NOT used in calculations. Digital devices employ several types of codes to represent character data: ASCII (American Standard Code for Information Interchange. ) Requires 7 bits for each character Provides 128 characters, including: uppercase, lowercase, punctuation, numerals. Extended ASCII is a superset of ASCII Uses 8 bits for each character (allows for graphical symbols) Unicode Uses 16 bits Provides code for 65, 000 languages

You Try! What does this say? 1010011 1110101 1100011 1100101 1110011 100001

Spell your first name with the ASCII Codes at the top of the noteguide! Share with your partners.

What is ASCII text? • Plain, unformatted text is sometimes called ASCII text and is stored in a so-called “text file” with a name ending in. txt. • On Apple devices, these files are labeled “Plain Text. ” • On Windows, these files are labeled “Text Document, ” like this: • ASCII text files can be created with text editors, such as Text. Edit and Notepad. • They are typically used for writing computer programs because executable program code cannot include formatting such as underlining and special fonts. They can also be used for creating Web pages.

How Does Formatting Get Added to Documents? • ASCII text files contain no formatting. They have no bold, italics, underlining, or font colors. There are no margins, columns, bullets, headers, or page numbers. • To create documents with styles and formats, formatting codes have to be embedded in the text. • There are many techniques for doing so, and each one produces a unique file format. These formats can be opened by the software that produced them. • Opening those files with other kinds of software requires conversion.

• Microsoft Word produces formatted text and creates documents in DOCX format • i. Work Pages produces documents in PAGES format. • Adobe Acrobat produces documents in PDF format. • The HTML markup language used for Web pages produces documents in HTML format. • Ebooks are created using the EPUB format. ***Formatting codes can be added to documents directly within the text stream, using some sort of delimiter to signal the beginning and end of the formatting command. When the document is displayed, the formatting codes are hidden. ***

What happens when you scan a document? When scanning to “digitalize” a document, you might have a choice between graphics formats and OCR. Graphics formats essentially capture a photo of the document OCR (optical character recognition) is a process that interprets individual characters during of after a scan. It assigns an ASCII code to each letter and outputs the document in a format that can be edited by a word processing software.

What is the difference between bits and bytes? • A bit (b) is an abbreviation for binary digit. Usually used in describing transmission speeds (data rates) EX: a cable Internet connection might transfer data from the Internet to your computer at 8 megabits per second EX: movie download speeds • A byte (B) is a group of 8 bits. Usually used in describing storage space or file sizes. EX: your i. Pad might store up to 60 gigabytes of music and video.

What Do the following prefixes mean? Kilo- “thousand” Giga- “billion” 1 kilobyte is approx. 1000 bytes 1 gigabyte is approx. 1, 000, 000 bytes Mega- Tera- “trillion” “million” 1 megabyte is approx. 1, 000 bytes 1 kilobyte is approx. 1, 000, 000 bytes

What comes next?

You Try! 2, 000 bytes = 2 MB 23, 000 KB = 23 MB (1000 KB = 1 MB) 500 KB = 0. 5 MB 16 GB is 16, 000 MB and 16, 000 / 5 = 3, 200 images

The next 3 questions here are from: https: //web. stanford. edu/class/cs 101/bits-gigabytes. html 5) Alice has 600 MB of data. Bob has 2000 MB of data. Will it all fit on Alice's 4 GB thumb drive? 6) Alice has 100 small images, each of which is 500 KB. How much space do they take up overall in MB? 7) Your ghost hunting group is recording the sound inside a haunted classroom for 20 hours as MP 3 audio files. About how much data will that be, expressed in GB? 8) Assume your Internet connection can transmit 1 million bits per second. Approximately how long would it take you to download 1 Terabyte of data? (Hint: first figure out how many bits a terabyte is, second be prepared to wait a long time).

Finish this table at home. Find on your own computer (people’s Answers will be slightly different)