CSE 3 Final Exam Details and History of Computing

• The CSE 3 Final Exam contains 80 questions.
• 20 questions will be sourced from the Midterm material.
• 60 questions will be sourced from the material after the Midterm.
• The exam is on Wednesday, March 19, from 8 AM to 10 AM.
• The exam is two hours long.
• The location is Baskin Engineering 152.

Computing Before Computers

• Augusta Ada King, Countess of Lovelace was an interpreter and promoter of Babbage's visionary work..
• Ada King wrote a plan using the Analytical Engine to calculate Bernoulli sequences.
• Ada King is known as the first computer programmer.

Computers in Perspective: An Evolving Idea

• At the same time as Ada King, the British government was assembling a top-secret team of mathematicians and engineers to crack Nazi military codes.
• The team, led by mathematician Alan Turing, completed Colossus in 1943 Colossus is considered by many to be the first electronic digital computer.
• Alan Turing was important in breaking Enigma, which was the German military's chief cipher machine.
• Turing is also known for the Turing Test, which is a basic test for artificial intelligence.

Evolution and Acceleration

• Vacuum tubes were used in early computers.
• Transistors replaced vacuum tubes, starting in 1956.
• By the mid-1960s, transistors were replaced by integrated circuits commonly known as silicon chips.

Freeware and Open Source

• Freeware is actually free without conditions.
• It can range from being unsophisticated to sophisticated, like Firefox or VLC Media Player.
• Open Source is free software with free source code.
• It is free to download, modify, and improve.

Moore's Law

• Gordon Moore's real version states that the number of transistors that can be inexpensively placed on an integrated circuit doubles every two years.
• Popular variations include the doubling of transistors every 18 months.
• Another variant is that processing speed and storage capacity will double every 18 months.
• The exponential growth can't continue forever and miniaturization will eventually approach atomic sizes, according to Gordon Moore.
• This trend isn't a true physical law, but more so a description of a modern trend.

Terminology

• Byte = 8 bits
• Kilobyte (KB) = 1 Thousand Bytes
• Megabytes (MB) = 1 Million Bytes
• Gigabytes (GB) = 1 Billion Bytes
• Terabytes (TB) = 1 Trillion Bytes
• Petabytes (PB) = 1 Quadrillion Bytes

Chapter 2 A Bit About Bits (continued)

• Two symbols can be used to represent or calculate all numbers.
• A calculator translates touching the numeric keypad into a series of 0s and 1s.
• Each number is then looked at as a component of its positional values, specifically a power of two.
• 19 will be represented as 00010011.

Input devices – dvorak keyboard

• The Dvorak keyboard was developed in 1936 to improve efficiency.
• The keyboard intends to limit hand movement.

Input devices – touch screen

• Resistive screens have edges that emit horizontal and vertical light beams.
• Capacitive screens create an electromagnetic field that is blocked by the electromagnetic field of your skin.
• This allows for multi-touch input.
• Touch screens allow for input and output from the same device.
• They are good for systems where a keyboard would be cumbersome.
• Touch screens are now common on smartphones, tablets, and some laptops.

US Copyright Law

• The US Constitution( Article I, Section 8) gives Congress the power to enact statutes to promote science and useful arts.
• Copyrights cover ideas and creative works.
• They last for 70 years + the life of the author, or up to 120 years for corporate authorship.
• Before the Bono Act of 1998, it was 50 years + the life of the author.
• Patents cover inventions.

Fair Use

• In general, exceptions are made for duplicating copyrighted content for criticism or commentary.
• This includes parody(even for commercial gain).
• Exceptions are also given for teaching, scholarship, or research.
• These exceptions aren't absolute.
• Courts can consider the amount of work duplicated and its effect on the market.
• Fair Use is a defense someone can bring up in court; it is not a guarantee to avoid being sued.

Linus Torvalds and the Software Nobody Owns

• Linus Torvalds is best known as the creator of Linux.
• The Linux kernel is an open-source operating system core
• Linus Torvalds also created Git.
• Git tracks changes in programming files modified by multiple authors.
• Github is a large repository of open-source software.
• Specific Linux Distributions include Ubuntu, CentOS, and Fedora.
• Local Connection: SCO Litigation took place in 2003.

Processing with Programs

• Natural languages resemble languages spoken by humans.
• Programming languages fall between machine language and natural human language.
• Compilers translate programming languages into machine language.
• Examples of this language are C++, JavaScript, Perl, and PHP.
• Machine language uses numeric codes that represent data.

Software Revsions, Updates, and Patches

• Software testing:
• Alpha testing involves trials by internal users and very select groups.
• Beta testing involves trails by external users (usually by volunteers).
• Newer releases often include additional features, with fixes to previous bugs.
• Major updates often come with new problems.
• Minor fixed, called "patches," are usually available for free.
• The advice to consumers is to never buy version 1.0 of anything.

Emulator Programs

• Emulator programs can "pretend" to be another operating system or hardware device.
• They can run programs written for that system.
• All applications may not work perfectly in an emulator.
• Can cause a drop-in system performance, especially with resource/graphics-intensive applications.
• Older systems are easier to emulate.

Software Applications: Tools for Users

• Licensing commercial software is copyrighted so it can't be legally duplicated for distribution to others without a software or volume license.
• Commercial software can be distributed via direct sale, retail stores, and websites.
• EULA is the end-user license agreement.

System Software: The Hardware-Software Connection

• Device drivers are small programs that enable input/output devices(keyboard, mouse, printer) to communicate with the computer.
• These drivers can either be included with the operating system or bundled with peripherals.
• Simpler devices, such as mice and keyboards, work without the full manufacturer's driver package installed.
• If a device doesn't work, replace the drivers on the manufacturer's website.
• Video drivers and printer drivers are the most troublesome.
• New PCs include hardware compatible with the newest Windows, but not older versions of Windows.
• This is not an accident.

The Electronic File Cabinet: Database Basics

• Database program: software tool for organizing the storage and retrieval of information.
• Database: A collection of information stored in an organized form on a computer.
• Databases are typically composed of one or more tables.
• A collection of records.
• A collection of related information.
• The type of information a field can be determined by its field type.
• Field type can be referred to as data type or field data type.
• It can be text or numeric.
• Numeric: date, GPA, account balance
• Text: Name, Major, Outstanding arrest warrants
• Database programs provide more than one way to view data.
• Form views show one record at a time.
• List views display several records in lists, similar to a spreadsheet.
• Most modern database management programs support standard language for programming complex queries called SQL.
• This is helpful for programmers and advanced users.
• Graphical user interfaces allow for point-and-click queries, which insulates users from any complexities.
• Specialized database software: preprogrammed for specific data storage and retrieval purposes.
• Geographical information systems (GIS): include geographic and demographic data in map form.

Key Concept: Data Compression

• Shrinking a file for smaller file sizes and faster transmission over the network.
• Data compression can be used for photos, videos, audio, text, and programs.
• Removing redundant information: repeated text, sounds, images, etc.
• Removing unnecessary information: sounds beyond the human hearing range or images too detailed to see at a given resolution.
• Lossy compression permanently loses some information.
• Lossless Compression can have all its information restored on decompression.

Vector vs bitmapped graphics

• Disclaimer: product contains neither ice nor cream and may contain traces of cheese, so do not consume.

Graphics File Formats

• GIF has a maximum of 255 colors per frame.
• GIF supports animation and lossless compression.
• JPG/JPEG offers a full range of colors and lossy compression.
• PNG is full of color range, very crisp and clear, and can be lossless.
• PNG file sizes are so large that they are better for infographics and banners than high-resolution photos.
• WebP is a newer Google-created image format that compresses existing JPGs and PNGs to smaller file sizes.
• WebP doesn't work with every browser or viewing software.
• HEIF is a high-efficiency file format with Lossy compression and small file sizes with good image quality; however, it is not compatible with web browsers yet.
• PDF is a vector file format that scales perfectly when magnified with full color and lossless compression; however, it has large file sizes.

Digital Audio Formats

• WAV/ AIFF: Standard formats for uncompressed audio; supported on Windows, Mac OS, and Linux.
• They create large files and are lossless.
• a CD track encoded with WAV or AIFF sounds identical to the original.
• MP3: A popular format for transmitting audio on the Internet.
• A CD track converted to MP3 format can be 1/10 the size of the original, but it still sounds very similar.
• WMA: An alternative to MP3 developed by Microsoft for Windows.
• WMA compression can result in smaller files of higher fidelity.
• WMA files may be protected by DRM.
• AAC: Apple's alternative to MP3 and WMA is used primarily by iTunes and iTunes Music Store.
• AAC compression is sonically superior to MP3 compression, and the files may be protected by DRM.
• OGG: Similar to WMA and AAC in sound quality and compression, and OGG Vorbis is open source and freely available.
• Not controlled by any company.
• FLAC: Free Lossless Audio Codec, which compresses audio files by about 40-50%, losing no information along the way.
• The broadcast format of choice for many audiophiles and the European Broadcasting Union.

Basic Network Anatomy

• A computer network is any system of two or more computers that are linked together.
• Networking is important because people share computer hardware, reducing costs as a result.
• People share data and software programs, thus increasing their efficiency and production.
• Networking helps people work together in a way that is otherwise difficult or impossible.
• Broadband connection:generally defined as a "fast" connection (cable, DSL, satellite)
• DSL uses standard phone lines and is provided by phone companies
• Cable modems provide fast network connections through cable television networks.
• High-speed wireless connections can connect computers to networks using radio waves rather than wires.
• Satellite dishes can deliver fast computer network connections as well as television programs.
• In 2015, the FCC redefined "broadband" to describe only connections of 25Mbps down/3Mbps up This was objected to strenuously by certain congress members as this does not currently meet Zoom's recommendation for a single-user connection.
• Fiber optic connections have DSL and cable modems don't have the bandwidth of fiber optic cables.
• The fiber optic cables replace copper wires in the worldwide telephone network.
• A fiber optic network can rapidly and reliably transmit multimedia data at the same time that it's handling voice messages.
• The type of network is built on physical media
• Twisted pair- Small LANs, 300 feet, low cost
• Coaxial cable- Large LANs, 600-2,500 feet, Medium cost
• Fiber optic- Network backbones: WANS, 1-25 miles, High cost
• Wireless/infrared- LANS 3-1,000 feet, Medium cost
• Wireless/radio-connecting things that move, varies considerably, High cost

Email, Instant Messaging, and Teleconferencing: Interpersonal Computing

• Private browsing is available in most web browsers and disables your browser history to keep it private from others to access that computer.
• This does NOT delete any records kept by other networks you are connected to.
• TOR Browser is more private browsing, connects to an anonymizing network that doesn't reveal your true IP address to any site you connect to.
• It can be slow and is not completely invulnerable to dedicated investigation. An IP address is not a person.
• If there is a legal offense tied to a particular IP address, then there needs to be additional verification to prove what person committed that offense.

Onion Browser

• This browser can browse the internet anonymously.
• You can download the laptop/desktop app from https://www.torproject.org/.
• It uses the TOR network to mask internet activity.
• Caution is advised when blindly downloading mobile TOR apps.
• Some are a little sketchy. If they cost money or are ad-supported, then avoid them. Use the apps recommended at https://support.torproject.org/tormobile/.
• DuckDuckGo is a privatizing search engine, which does not track your activity or personalize your results.
• Can also be used as your chosen/default search engine on any Web Browser.

VPN

• Virtual private networking subscription services are not free, but they can keep everything you do anonymous.
• To choose your VPN provider wisely, search for providers that do not keep logs of your data. -Free VPNs are almost always bad VPNs, except for the UCSC VPN. -Which isn't really free, you're just paying for it whether or not you use it.
• recommended Services (for now - always check recent reviews):
• IPVanish
• ExpressVPN
• NordVPN

Inside the Internet

• The host is named using DNS(domain name system), which translates IP addresses into a string of names.
• This has led to legal fights over rights to certain domain names and Cyber-squatting, which is grabbing domain names to resell later.
• Top-level domains include:
• .edu - educational sites
• .com - commercial sites
• .gov - government sites
• .mil - military sites
• .org - nonprofit organizations
• TCP breaks messages into packets. -Each packet has all the information needed to travel from network to network. -Host systems called routers determine how to route transmissions.
• IP is the address for the packets. -Each Internet host computer has a unique IP address. -Each address(using IPv4) is comprised of four sets of numbers between 0 and 255 separated by periods, such as128.114.113.19.
• The world is gradually moving to IPv6 instead of IPv4.
• IPv4: 232: 4,294,967,296 addresses.
• Example: 128.114.113.19 = ucsc.edu
• IPv6: 2128: 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses Example: E42B.324D.3C34.324A.C3D9.5F32.8BB8.32D2

Software Sabotage: Viruses and Other Malware

• Malware: malicious software, or any type of intentionally invasive, unwanted software.
• Malware can include:
• Trojan horse: Performs a useful task while also running undesired or actively harmful routines Example: A bittorrent client that uses your processor to mine cryptocurrency- Example: An"anti-virus"program that installs ransomware.
• Virus: spreads by making copies of itself from program to program.
• Can corrupt data, damage systems, spread malware/spyware, or often do nothing at all, making it only an intellectual challenge.
• Examples: Macro viruses and email viruses - most are filtered out by email servers.
• Worm: Program that travels independently over computer networks and seeks uninfected sites.
• Make online purchases using a credit card.
• Separate credit card with low credit for online transactions, as credit card charges are easier to dispute than debit card charges.
• Make certain a secure Web site is is managing any sensitive transactions; should look for "https" in the URL.
• Refrain from putting personal information in the subject line of an email.
• The subject line is visible to anyone monitoring network traffic.
• Do Not disclose personal information over the phone.
• Refrain from giving social security or driver's license numbers over the phone.
• Shred or burn sensitive information

Computer Security: Reducing Risks

• The security system you are granted access to is based on:
• Identity Token- Something you have
• i.e. A key, an ID card with a photo, or a smart card containing digitally encoded identification in a built-in memory chip.
• Do not confuse with a Token ID, which is used by online services for a single-sign-on across multiple applications.
• Passcode ID - Something you know.
• i.e. A password, an ID number, a lock combination, or a piece of personal history, such as your mother's maiden name.
• Signature ID -Something you do.
• i.e. Signature, typing speed, and error patterns.
• Biometric ID - Something about you.
• i.e. A voice print, fingerprint, retinal scan, or other measurement of individual body characteristics.
• These measurements are collectively called biometrics and multi-factor authentication, which is two or more of the above methods.
• Hacker(or cracker) refers to people who break into computer systems.
• Webjackers hijack Web pages and redirect users to other sites.
• Denial-of-service attacks(DOS attack) bombard servers and Web sites with traffic that shuts down networks.
• Passwords are the most common tool for restricting access to a computer and should be effective.
• Here are some recommendations.
• Not real words
• Not names
• Changed frequently
• Kept secret
• A combination of letters and numbers
• Not shared across multiple accounts Choosing a real word or name for your password makes it susceptible to a dictionary attack, which is a comparison of your password to every word in the dictionary.
• Beware of hardware and software keyloggers.
• Software keyloggers can log all keystrokes.
• USB Keyloggers can be placed between external keyboards and desktop computers.
• Keylogger may not be able to be detected by software. Making messages secure from outsiders requires encryption software as encryption software scrambles the sent message using a key. -There needs to be a different key to unscramble the message. Uninterruptible power supply (UPS) can protect computers from data loss during power failures. -A laptop's battery can serve as a built-in UPS. Surge protectors shield electronic equipment from power spikes. Have a routine for making regular backups Best back ups are automated.