CE100: Intro to Computer Systems

• The CE100 course is titled Introduction to Computer Systems.
• The material for section 1 and 3 of this course is taught by Tariq Mohedat.
• The material for section 2 of this course is taught by Farid Jradi.
• The course duration is 16 weeks (1 + 1 CH per week).
• Lecture notes and homework will be posted on the webpage along with a tentative schedule.
• Soft copies of homework are to be submitted to Moodle by the due date.
• 25% of the marks will be deducted per day for late submissions of homework.
• No submission is accepted after the fourth day of the due date of homework.
• Quizzes will be conducted in class with a policy of 10% on each.
• Lecture slides will be available online and lecture videos will be available on YouTube soon after class.
• Exams consist of one Midterm (20%) and one Final Term (40%)
• KCST rules and regulations must be followed, and the Moodle web portal should be checked regularly for exam schedules.
• 15% absences are allowed for various emergencies.
• Attendance will be marked randomly during class and students cannot attend another section.
• Sick leave or emergency leave is not acceptable via email.

Introduction to Computer and Systems

• Computers are electronic devices.
• Computers can perform all arithmetic and logical operations.
• People use computers at school for writing papers, research, email, and online classes.
• Computers are used at work for analyzing data, making presentations, business transactions, communicating and controlling machines.
• People use computers at home for paying bills, shopping online, communicating, and playing computer games.
• Devices that are computers are SmartPhones, iPods, Tablets and Car navigation systems (GPS).
• Computers are designed to do any job that their programs tell them to do.
• A program is a set of instructions that a computer follows to perform a task such as Microsoft Word and PowerPoint.
• Programs are commonly referred to as software.
• Programmers or Software Developers create computer software including designing, creating and testing computer programs.

Hardware and Software

• Physical devices that a computer consists of, are referred to as the computer's hardware.
• Programs that run on a computer are referred to as software.
• A computer is a system of devices that work together consisting of:.
  • Central Processing Unit (CPU)
  • Main memory
  • Secondary storage
  • Input devices
  • Output devices
• The CPU is the part of a computer that runs programs and is also referred to as the processor.
• A computer cannot run software without a CPU.
• Running or executing a program happens when a computer performs the tasks that the program tells it to do.
• ENIAC was the world's first programmable computer.
  • ENIAC was built in 1945.
  • ENIAC was designed to calculate artillery ballistic tables for the U.S. Army.
  • The CPU for ENIAC was 8 feet tall, 100 feet long, and weighed 30 tons.
• Computer memory can be primary or secondary.
• Types of data access are random access and sequential access.
• Random Access, also called Direct Access, retrieve data directly such as CD-ROM drive, Hard disc drive, and floppy disc drive
• Sequential access devices have to move through all the data to find what is needed, such as Cassette tape and magnetic tape.
• Sequential access goes from file A to file Z passing through all files in between and is sometimes called serial access.
• Tapes are sequential access media.
• Random Access refers to the ability to access data at random in a random-access system and jump directly to a file.
• Disks are random access media.
• RAM is considered the computer's work area while the computer stores what program that is running as well as the data.
• RAM is commonly known as random-access memory.
• Data is quickly accessed randomly, also it is a volatile(temporary) type of memory.
• RAM is used for temporary storage and is erased when computer is turned off.
• Read-Only Memory (ROM) can read the contents but its contents cannot be changed or store any additional data there.
• ROM is nonvolatile, meaning it does not lose its contents, even when the computer's power is turned off.
• ROM is used to store programs that are important for operating a system, such as the computer's startup program, which is executed each time the computer is started.
• Secondary Storage Devices are types of memory that can hold data for long periods of time.
• Programs and important data is stored in secondary storage.
• Data is magnetically encoded onto a circular disk
• Most computers have an internal disk drive although some have external disk drives which are used to create backup copies.
• Solid-state drives are becoming increasingly popular, does not contain a disk, and stores data in solid-state memory.
• Solid-state have no-moving parts and operates faster than a traditional disk drive
• USB drives are small devices that plug into the computer's universal serial bus (USB) port.
• USB do not contain a disk, data is stored on flash memory and are known as memory sticks and flash drives, they're inexpensive, reliable, and small.
• Optical devices (CD or DVD) data is encoded as a series of pits on the disc's surface and uses laser to encode the data.
• Optical devices holds large amounts of data and is great for creating backups.
• Storage devices and optical disks formats are CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD+RAM, Tape.
• Cloud Storage stores data on a remote server via the internet or through a company's private network.
• Access is possible form many different devices, and from any location with a network connection.
• Cloud data can be used as backup for important data stored on a computer's disk.
• Input is any data the computer collects from people and other devices and the hardware component that collects the data is called an input device.
• Common input devices are Keyboard, Mouse, Touch screen, Scanner, Microphone and Digital camera
• QWERTY Keyboards was designed by Christopher Latham Sholes in 1870s to "slow down" typing, and to prevent the types from jamming.
• Doug Englebart invented Mouse in 1966, at Xerox PARC.
• Footmouse is equivalent to conventional mouse but no RSI (Repetitive Stress Injury).
• Bar Code Readers has Photoelectric scanner and can Read bar codes that uses alternating black & white vertical bars.
  • The most common code is Universal Product Code (UPC).
  • Barcode readers is seen in grocery stores and retail stores.
• Microphones records Speech (also for text input).
• Brain activity input using a neural network system can distinguish 5 brain patterns for up, down, L, R & click.
• Touchscreens also serves as input.
• Output is any data the computer produces for people or for other devices.
• Hardware that formats and presents the data is called an output device.
• Common output devices include monitors and speakers.

Monitor and Printer output

• Monitor output is characterized by Resolution, Pixel (Picture element) and Size.
• Printers prints what it gets as output with two main categories, Inkjet (liquid) and Laser Jet Printer (toner).
• Everything a computer does is controlled by software divided into system software and application software.

System Software

• Programs control and manage the basic operations of a computer are referred to as system software.
• System Software Includes the following types such as Operating System, Utility Programs and Software Developments Tools.

Application Software

• Programs people normally spend most of their time running on their computers performing tasks such as word processing, spreadsheet database and presentation
• All data in a computer is converted to sequences of 0s and 1s.
• A computer's memory is divided into tiny storage locations known as bytes.
  • One byte represents one number.
  • A byte is divided into eight smaller storage locations known as bits (binary digits).
  • Bits are tiny electrical components that can hold either a positive or a negative charge.
  • A positive charge is similar to a switch in the on position, represented by the digit 1.
  • A negative charge is similar to a switch in the off position, represented by the digit 0.
  • Each digit in a binary number has a value assigned to it.
  • The largest value that can be stored in a byte with eight bits is 255.
  • Two bytes are used for larger numbers with maximum value of 65535

Data Storage

• Characters are stored in the computer's memory as binary number.
• ASCII (American Standard Code for Information Interchange) is a coding scheme.
• ASCII is a set of 128 numeric codes is limited.
• Unicode is an extensive encoding scheme.
• It is compatible with ASCII.
• It represents characters for many languages in the world
• Other types of Data
  • Digital data is data that is stored in binary.
  • A digital device is any device that works with binary data.
  • Digital images are composed of tiny dots of color known as pixels (picture elements)
  • Digital sound is broken into small pieces known as samples.
• A computer's CPU can only understand instructions in machine language because people find it difficult, thus other programming languages have been invented

How A Program Works

• CPU is the most important component in a computer.
• CPU is not a brain or smart, but it is an electronic device that is designed to do specific things.
• Operations a CPU is designed to do are:
  • Read a piece of data from main memory.
  • Adding two numbers or subtracting one number from another number.
  • Dividing one number by another number or multiplying two numbers.
  • Moving a piece of data from one memory location to another.
  • Determining whether one value is equal to another value.
• The Fetch-decode-execute cycle is when a CPU executes the instructions in a program and consists of Fetch, Decode and Execute.
• Assembler translates an assembly language program to a machine language program.
• Assembly language uses short words that are known as mnemonics.
• Machine language is difficult to write.
• An assembler is used to translate an assembly language program to machine language.
• High-level languages allow for creating powerful and complex programs without knowing how the CPU works, using words that are easy to understand.
• Assembly language is regarded as low -level languages, some examples of High-level languages are:
  • Java, C++, Python, Visual Basic, C#, Ada, and Fortran.
• Key words or reserved words have have specific meaning and purpose in the programming language.
• Operators perform various operations on data
• Syntax is a set of rules that are to be followed writing a program
• Statements are individual instructions written in a programming language

Compilers and Interpreters

• Compilers and Interpreters include
  • The statements written in a high-level language are called source code,
  • The source code is translated to machine language using a compiler or an interpreter.
  • Syntax error is a mistake such as a:
    • Misspelled word, missing punctuation characteror, or Incorrect use of an operator
    • A Compiler is a program that translates a high-level language program into a separate machine language program
    • A n interpreter is a program that both translates and executes the instructions in a high-level language program.

Software

• Software can be divided to:.
• System software that controls operations that enhance a computer- Such as operating system, utility programs software and development tools.
• Application Software such as Microsoft Word, email programs and web browsers.