Multimedia computer

A multimedia computer is a computer that is optimized for high multimedia performance. Early home computers lacked the power and storage necessary for true multimedia.

The Basic Elements of Multimedia

• Text

• Graphic

• Animation

• Video

• Audio

TEXT 

Text are characters that are used to create words, sentences, and paragraphs.

Graphics 

A digital representation of non-text information, such as a drawing, chart, or photograph.

Animation 

Animation is Flipping through a series of still images. It is a series of graphics that create an illusion of motion.

Video

Video means the photographic images that are played back at speeds of 15 to 30 frames a second and the provide the appearance of full motion.

Audio 

Audio means music, speech, or any other sound.

Categorization

Two types of Multimedia presentation

• Linear Presentation

• Non-linear Interactive

 

Linear active content progresses often without any navigational control for the viewer such as a cinema presentation.

Non-linear uses interactivity to control progress as with a video game or self-paced computer based training. Hypermedia is an example of non-linear content.

Usage

Multimedia finds its application in various areas including, but not limited to:

• Advertisements

• Art

• Education

• Entertainment

• Engineering

• Medicine

• Mathematics

• Business

• Scientific research

Advantages of using Multimedia

• It is very user-friendly. It doesn’t take much energy out of the user, in the sense that you can sit and watch the presentation, you can read the text and hear the audio. 

• It is multi sensorial. It uses a lot of the user’s senses while making use of multimedia, for example hearing, seeing and talking.It is integrated and interactive. All the different mediums are integrated through the digitisation process. Interactivity is heightened by the possibility of easy feedback.

• It is flexible. Being digital, this media can easily be changed to fit different situations and audiences.

• It can be used for a wide variety of audiences, ranging from one person to a whole group.

Disadvantages of using Multimedia

• Information overload. Because it is so easy to use, it can contain too much information at once.

• It takes time to compile. Even though it is flexible, it takes time to put the original draft together.

• It can be expensive. As mentioned in one of my previous posts, multimedia makes use of a wide range of resources, which can cost you a large amount of money.

• Too much makes it unpractical. Large files like video and audio has an effect of the time it takes for your presentation to load. Adding too much can mean that you have to use a larger computer to store the files.

 

 

 

Development

Computer science, the study of computers and computing, including their theoretical and algorithmic foundations, hardware and software, and their uses for processing information. The discipline of computer science includes the study of algorithms and data structures, computer and network design, modeling data and information processes, and artificial intelligence. Computer science draws some of its foundations from mathematics and engineering and therefore incorporates techniques from areas such as queueing theory, probability and statistics, and electronic circuit design. Computer science also makes heavy use of hypothesis testing and experimentation during the conceptualization, design, measurement, and refinement of new algorithms, information structures, and computer architectures.

Computer science is considered as part of a family of five separate yet interrelated disciplines: computer engineering, computer science, information systems, information technology, and software engineering. This family has come to be known collectively as the discipline of computing. These five disciplines are interrelated in the sense that computing is their object of study, but they are separate since each has its own research perspective and curricular focus. (Since 1991 the Association for Computing Machinery [ACM], the IEEE Computer Society [IEEE-CS], and the Association for Information Systems [AIS] have collaborated to develop and update the taxonomy of these five interrelated disciplines and the guidelines that educational institutions worldwide use for their undergraduate, graduate, and research programs.)

The major subfields of computer science include the traditional study of computer architecture, programming languages, and software development. However, they also include computational science (the use of algorithmic techniques for modeling scientific data), graphics and visualization, human-computer interaction, databases and information systems, networks, and the social and professional issues that are unique to the practice of computer science. As may be evident, some of these subfields overlap in their activities with other modern fields, such as bioinformatics and computational chemistry. These overlaps are the consequence of a tendency among computer scientists to recognize and act upon their field’s many interdisciplinary connections.

Development Of Computer Science

Computer science emerged as an independent discipline in the early 1960s, although the electronic digital computer that is the object of its study was invented some two decades earlier. The roots of computer science lie primarily in the related fields of mathematics, electrical engineering, physics, and management information systems.

Mathmeatics is the source of two key concepts in the development of the computer—the idea that all information can be represented as sequences of zeros and ones and the abstract notion of a “stored program.” In the binary number system, numbers are represented by a sequence of the binary digits 0 and 1 in the same way that numbers in the familiar decimal system are represented using the digits 0 through 9. The relative ease with which two states (e.g., high and low voltage) can be realized in electrical and electronic devices led naturally to the binary digit, or bit, becoming the basic unit of data storage and transmission in a computer system.

Electrical Engineering provides the basics of circuit design—namely, the idea that electrical impulses input to a circuit can be combined using Boolean Algebra to produce arbitrary outputs. (The Boolean algebra developed in the 19th century supplied a formalism for designing a circuit with binary input values of zeros and ones [false or true, respectively, in the terminology of logic] to yield any desired combination of zeros and ones as output.) The invention of the transistor and the miniaturization of circuits, along with the invention of electronic, magnetic, and optical media for the storage and transmission of information, resulted from advances in electrical engineering and physics.

Managment Information Systems, originally called data processing  systems, provided early ideas from which various computer science concepts such as sorting, searching, databases, information retrievel, and graphical user interfaces evolved. Large corporations housed computers that stored information that was central to the activities of running a business—payroll, accounting, inventory management, production control, shipping, and receiving.

 

Computer security

Computer security, cybersecurity or information technology security is the protection of computer systems and networks from the theft of or damage to their hardware, software, or electronic data, as well as from the disruption or misdirection of the services they provide.

Computer Security and its types

• Information Security is securing information from unauthorized access, modification & deletion

• Application Security is securing an application by building security features to prevent from Cyber Threats such as SQL injection, DoS attacks, data breaches and etc.

• Computer Security means securing a standalone machine by keeping it updated and patched

• Network Security is by securing both the software and hardware technologies

• Cyber Security is defined as protecting computer systems, which communicate over the computer networks

Why is Computer Security Important?

In this digital era, we all want to keep our computers and our personal information secure and hence computer security is important to keep our personal information protected. It is also important to maintain our computer security and its overall health by preventing viruses and malware which would impact on the system performance.

Computer Security Practices

Computer security threats are becoming relentlessly inventive these days. There is much need for one to arm oneself with information and resources to safeguard against these complex and growing computer security threats and stay safe online. Some preventive steps you can take include:

• Secure your computer physically by:
  • Installing reliable, reputable security and anti-virus software
  • Activating your firewall, because a firewall acts as a security guard between the internet and your local area network 
• Stay up-to-date on the latest software and news surrounding your devices and perform software updates as soon as they become available
• Avoid clicking on email attachments unless you know the source 
• Change passwords regularly, using a unique combination of numbers, letters and case types
• Use the internet with caution and ignore pop-ups, drive-by downloads while surfing
• Taking the time to research the basic aspects of computer security and educate yourself on evolving cyber-threats
• Perform daily full system scans and create a periodic system backup schedule to ensure your data is retrievable should something happen to your computer.

Computer security threats

Comupter Security Threats are possible dangers that can possibly hamper the normal functioning of your computer. In the present age, cyber threats are constantly increasing as the world is going digital. The most harmful types of computer security are:

Viruses

A computer virus is a malicious program which is loaded into the user’s computer without user’s knowledge. It replicates itself and infects the files and programs on the user’s PC. The ultimate goal of a virus is to ensure that the victim’s computer will never be able to operate properly or even at all. 

Computer Worm

A computer worm is a software program that can copy itself from one computer to another, without human interaction. The potential risk here is that it will use up your computer hard disk space because a worm can replicate in greate volume and with great speed.

Phishing

Disguising as a trustworthy person or business, phishers attempt to steal sensitive financial or personal information through fraudulent email or instant messages. Phishing in unfortunately very easy to execute. You are deluded into thinking it’s the legitimate mail and you may enter your personal information.

Botnet

A botnet is a group of computers connected to the internet, that have been compromised by a hacker using a computer virus. An individual computer is called ‘zombie computer’. The result of this threat is the victim’s computer, which is the bot will be used for malicious activities and for a larger scale attack like DDoS.

Rootkit

A rootkit is a computer program designed to provide continued privileged access to a computer while actively hiding its presence. Once a rootkit has been installed, the controller of the rootkit will be able to remotely execute files and change system configurations on the host machine.

Keylogger

Also known as a keystroke logger, keyloggers can track the real-time activity of a user on his computer. It keeps a record of all the keystrokes made by user keyboard. Keylogger is also a very powerful threat to steal people’s login credential such as username and password.

 

Fundamental Concepts

A computer is basically a programmable machine capable to perform arithmetic and logical operations automatically and sequentially. It is also known as a data processor, as it can store, process, and retrieve data as per the wish of the user.

Basic Functions of a Computer

Taking data and instructions from a user, processing the data as per instructions, and displaying or storing the processed data, are the four major functions of a computer. These functions are also known as the input function, process function, output function, and storage function, respectively.

To provide these functions, a computer uses its components or devices. Usually, components of a computer are designed to perform only one of these four functions. But, some specialized components or devices are designed to perform two, three or all four functions. For example, a hard disk can perform three functions: input (when files are read), storage (when files are saved), and output (when files are written).

Components or devices of a computer, based on the function in which they are used, can be classified into four major types: the input devices, output devices, storage devices, and processing devices. For example, if a component processes the given instructions, the component is known as the processing device. Or if a device displays the processed data, the device is known as the output device.

Input function and devices

 

A computer is a data processing machine. It does nothing until a user (or a script or a program) provides the data that needs to be processed and the instructions that tell it how to process the data.

Any standard device or component that a user uses to instruct a computer is known as the standard input device. In other words, a computer uses its standard input devices or components to get instructions from a user.

The most common input devices are the keyboard and mouse. Almost all modern computers have these devices. Other common input devices are scanners, microphones, USB drives, and webcams.

Input data and instruction can also be generated from a non-standard input device such as the hard disk and CD/DVD. For example, a batch file in the Windows system may instruct the CPU to execute a program or a script at a particular time.

Installation disks are another good example of non-standard input devices. Usually, they contain a script or an executable program that automatically starts the installation process as soon as the disk is read.

Process function and devices

Once the data and instructions are received by the input function, the computer starts the processing function. In this function, a computer processes the received data according to the instructions.

To process the input data according to the instructions, the computer uses the CPU. A CPU is the main processing component of a computer. It processes user instructions, executes scripts and programs, and runs commands of the OS that provide a platform for installing and using application software.

Other important processing components are auxiliary processors. Auxiliary processors are also known as onboard processors. Auxiliary processors are used in devices to enhance their functionalities. You can think of an auxiliary processor as the private CPU of a device.

Only components or devices that provide the complex functionality such as Graphics cards, I/O devices, and network interface cards use auxiliary processors. For example, if a user draws an image, the auxiliary processor on the graphics card performs all calculations that require in drawing the image on the display device.

The following image shows a sample of both a CPU and an auxiliary processor.

Output function and devices

 

After processing the input data, the CPU, auxiliary processor, or the process function sends the processed data to the output function or to the default or configured output device. By default, computers use monitors as the default output device.

Aside from monitor, a variety of output devices are also available. Each output device presents the processed data in a different form, for example, a monitor, a printer, and a speaker displays, prints, and plays the processed data, respectively.

A user, based on his requirement, can connect and use two, three or more output devices to the computer. For example, after viewing the processed data, a user can send it to the printer for printing.

Storage function and devices

Storing data and information is the fourth major function of a computer. This function allows us to save the processed data for later use. To store data and information, a computer uses two types of storage components: temporary and permanent.

Temporary storage components are used to store data temporarily. Data stored in a temporary storage component is erased when the system is shutdown. RAM is a compulsory temporary storage component. A computer uses the ram to store the running applications and their data.

Permanent storage components are used to store data permanently. Data stored in a permanent storage component is not erased when the system is shutdown. The hard disk is the most common permanent storage component. Usually, all computers have at least one hard disk to store data. Other common permanent storage components or devices are external drives, USB drives, and CD/DVD.

The 4 Primary Hardware Concerns for New Computers

Computer descriptions these days come with a lot of specifications that use a lot of technical jargon. This can be confusing if you aren't sure what you're looking for! By following the information listed below, you can look for key words that will help you zero in on the computer that will last for your entire time here at UNI!

Computer Speed (the processor)

The most common processor found in computers today is from Intel. The Intel Core series of processors perform well and are generally recommended for a computer that you will bring to UNI. When reading a computer listing, look for something similar to Intel 6th generation Core processors. For gaming, intense graphic design or video editing, or just maximum longevity, pick a Core i7 processor (the most powerful). The Core i7 processor will deliver the fastest speed and most processing power. Keep in mind, on laptops, a Core i7 may slightly reduce the battery life due to the extra power needs for the stronger processor. UNI Information technology recommends a Core i5 at a minimum.

Storage (the hard drive)

Hard drives come in two varieties today: the magnetic, spinning disk (HDD) or the Solid State Drive (SSD). SSDs are more expensive, but recommended for maximum longevity of your computer.

• The spinning disk (HDD) is generally cheaper and comes in much larger sizes. These drives are good for storage (for example, if you have a lot of digital pictures, music, or movies). You can find HDDs in 500GB to several terabytes in size.
• The Solid State Drive (SSD) is generally smaller in terms of amount of storage available and more expensive. It is however, much faster than it's older, HDD cousin. Upgrading from an HDD to a SSD in an older computer will make it have new life! Ensuring the computer you bring to UNI has an SSD will make it faster and lighter. With cloud storage available to you at UNI (Google Drive), the smaller hard drive might not be an issue. Pick up an SSD no smaller than 256GB if possible.

Memory (RAM)

If a hard drive is like the bookshelf in a computer (where the computer stores information for retrieval, like a bookshelf storing books) then the RAM or computer's memory is like the desk surface. The larger the desk surface (the greater the amount of RAM or memory), the more things a person can do at once. If you have a large desk you can have several papers laying out at once, a book open, and generally it is more conducive to having more research materials spread out and available. Likewise, the more memory your computer has, the more programs or applications it can run at the same time. UNI recommends no less than 8GB of RAM. For maximum longevity, pick 16GB.

WiFi Ability (wireless network card)

UNI has deployed high-speed and secure WiFi across campus in areas that are important to students like Maucker Union, the Rod Library, classrooms, and even outside in some instances! To take full advantage of the WiFi, you should ensure that your wireless network card is a dual band radio capable of both 2.4GHz and 5GHz frequencies (most modern computers have this). You'll want to look for dual band AC wireless or something similar in the specifications listing. This will be the most compatible with UNI's wireless network.

Other Concerns for a New Computer

If you've followed the hardware advice above, you should have a computer that is fairly well equipped for your entire collegiate career here at UNI. There are a few other things to consider, however, when making a new computer purchase. The following section will review those with you.

Warranty

UNI Information Technology recommends a minimum three year hardware warranty. This will ensure the manufacturer or reseller will cover any broken computer hardware for at least three years. This is especially important for laptops as they are harder to work on yourself. 

UNI does not recommend that you purchase any type of software tuning/maintenance/assistance from your manufacturer or reseller. Some companies will try and sell you a "tune up" before you even walk out of the door! You do not need this assistance as Information Technology at UNI can help you with the software on your computer.

Size/Weight

More and more professors are allowing the use of laptops during class. A smaller, lighter laptop will be easier to carry across campus during your day. It is also more likely to have better battery life. Larger, heavier laptops are often-times better for gaming or video-intense applications, but will not be as fun to carry across campus.

Operating System

For Windows-based computers, UNI Information Technology recommends Windows 10 home or professional.

For Apple computers, UNI recommends the latest version of macOS.

Major/Field of Study

Some majors or fields of study use different types of computer hardware. It might be worth checking with the departmental office of the department your major resides in.

Motherboard

The motherboard is the backbone that ties the computer's components together at one spot and allows them to talk to each other. Without it, none of the computer pieces, such as the CPU, GPU, or hard drive, could interact. Total motherboard functionality is necessary for a computer to work well.

A motherboard provides connectivity between the hardware components of a computer, like the processor (CPU), memory (RAM), hard drive, and video card. There are multiple types of motherboards, designed to fit different types and sizes of computers.

Each type of motherboard is designed to work with specific types of processors and memory, so they don't work with every processor and type of memory. However, hard drives are mostly universal and work with the majority of motherboards, regardless of the type or brand.

Below is a picture of the ASUS P5AD2-E motherboard with labels next to each of its major components. Clicking on the image directs you to a larger and more detailed version.

What was the first motherboard?

The first motherboard is considered to be one used in the IBM Personal Computer, released in 1981. At the time, IBM called it a "planar" instead of a motherboard. The IBM Personal Computer and the motherboard inside it would set the standard for IBM-compatible computer hardware going forward.

Motherboard components

• Expension Slots
• 3 pin case fan connectors.
• Back pane connectors.
• Heat Sink.
• Inductor.
• Capacitor.
• CPU socket.
• Northbridge.
• Screw Hole.
• Memory Slot.
• Super I/O.
• Floopy Connection etc.

The Characteristics of a Motherboard

While many people think of the CPU as their computer's brain, the motherboard is like its nervous system and spinal cord. Not only does the motherboard provide a place for the CPU to sit, but it also handles every bit of data that passes in and out of the CPU.

Form Factor

While you can get capable motherboards in any size, its form factor is an important factor in choosing a motherboard. If you want to build a very small computer, a small form-factor board like a 9.6-inch square micro-ATX or 6.7-inch square mini-ITX board is your best choice. Larger motherboards, like the 11.2-by-8.2 inch mini-ATX or 12-by-9.6 inch full-size ATX board, not only fit in larger cases, but also have room for more components, connectors and expansion slots.

CPU Socket and Chipset

When choosing a motherboard, look for one with a CPU socket that will accommodate your chosen type of CPU. Not only do processors from Intel and AMD have different socket requirements, but different processors from the same manufacturers will also require a specialized socket. In other words, an Intel motherboard won't support an AMD processor and won't support certain Intel processors as well. In addition to choosing a compatible socket, the chipset on the motherboard will determine how quickly the computer can run, what additional features it supports and how much memory it can access.

Slots

Motherboards typically have three types of slots. Memory slots let you plug RAM modules into the computer. The more slots you have, the more memory you can add. The slots are also specific to a given type of RAM, so a motherboard with double data rate type 3 slots will only accept DDR3 memory modules. Motherboards also have high-speed PCI Express slots for graphics cards as well as regular PCI slots for expansion cards. While devices that once would have plugged into a PCI slot, like video capture cards or modems, are frequently now available as USB devices, the high-speed PCI-Express x16 slots are still necessities for graphics cards.

Connectors

Motherboards have a broad range of both internal and external connectors. At a minimum, you can expect to find internal USB headers and external USB ports, internal serial advanced technology attachment ports for drives, connectors for case LEDs and switches, and external audio ports. Some motherboards add support for USB 3.0, graphics connectors for their on-board graphics system, an external eSATA port for high-speed connections to external drives and even legacy ports like parallel or serial connectors.

 

ROM

ROM (read only memory) is a flash memory chip that contains a small amount of non-volatile memory. Non-volatile means that its contents cannot be changed and it retains its memory after the computer is turned off.

History of ROM

Read-only memory were employed as non-volatile storage for programs in most early stored-program computers, such as ENIAC after 1948. ... Most home computers of the 1980s stored a BASIC interpreter or operating system in ROM as other forms of non-volatile storage such as magnetic disk drives were too costly.

Types of ROM

• Programmable read-only memory (PROM), or one-time programmable ROM (OTP), can be written to or programmed via a special device called a PROM programmer. Typically, this device uses high voltages to permanently destroy or create internal links (fuses or antifuses) within the chip. Consequently, a PROM can only be programmed once.

• Erasable programmable read-only memory (EPROM) can be erased by exposure to strong ultravoilet light (typically for 10 minutes or longer), then rewritten with a process that again requires application of higher than usual voltage. Repeated exposure to UV light will eventually wear out an EPROM, but the endurance of most EPROM chips exceeds 1000 cycles of erasing and reprogramming. EPROM chip packages can often be identified by the prominent quartz "window" which allows UV light to enter. After programming, the window is typically covered with a label to prevent accidental erasure. Some EPROM chips are factory-erased before they are packaged, and include no window; these are effectively PROM.

• Electrically erasable programmable read-only memory (EEPROM) is based on a similar semiconductor structure to EPROM, but allows its entire contents (or selected banks) to be electrically erased, then rewritten electrically, so that they need not be removed from the computer (or camera, MP3 player, etc.). Writing or flashing an EEPROM is much slower (milliseconds per bit) than reading from a ROM or writing to a RAM (nanoseconds in both cases).

Where is the ROM on a computer?

For the computer, the main EEPROM and BIOS is on the computer motherboard.

How does ROM work?

ROM is sustained by a small, long-life battery in the computer. It contains two basic components: the decoder and the or logic gates. In ROM, the decoder receives input in binary form; the output will be the decimal equivalent. The OR gates in ROM use the decoder's decimal output as their input.

ROM performs like a disk array. It contains a grid of rows and columns that are used to turn the system on and off. Every element of the array correlates with a specific memory element on the ROM chip. A diode is used to connect the corresponding elements.

When a request is received, the address input is used to find the specific memory location. The value that is read from the ROM chip should match the contents of the chosen array element.

 

 

 

RAM

Alternatively referred to as main memory, primary memory, or system memory, RAM (random-access memory) is a hardware device that allows information to be stored and retrieved on a computer. RAM is usually associated with DRAM, which is a type of memory module. Because data is accessed randomly instead of sequentially like it is on a CD or hard drive, access times are much faster. However, unlike ROM, RAM is a volatile memory and requires power to keep the data accessible. If the computer is turned off, all data contained in RAM is lost.

History of RAM

The first form of RAM came about in 1947 with the use of the Williams tube. It utilized a CRT (cathode ray tube); the data was stored on the face as electrically charged spots.

The second widely used form of RAM was magnetic-core memory, invented in 1947. Frederick Viehe is credited with much of the work, having filed for several patents relating to the design. Magnetic-core memory works through the use of tiny metal rings and wires connecting to each ring. One bit of data could be stored per ring and accessed at any time.

However, RAM, as we know it today, as solid state memory, was first invented in 1968 by Robert Dennard. Known specifically as dynamic random-access memory, or DRAM, transistors were used to store bits of data.

 

Types of RAM

• DRAM (pronounced DEE-RAM), is widely used as a computer’s main memory. Each DRAM memory cell is made up of a transistor and a capacitor within an integrated circuit, and a data bit is stored in the capacitor. Since transistors always leak a small amount, the capacitors will slowly discharge, causing information stored in it to drain; hence, DRAM has to be refreshed (given a new electronic charge) every few milliseconds to retain data.
• SRAM (pronounced ES-RAM) is made up of four to six transistors. It keeps data in the memory as long as power is supplied to the system unlike DRAM, which has to be refreshed periodically. As such, SRAM is faster but also more expensive, making DRAM the more prevalent memory in computer systems.

What are the common types of DRAM?

• Synchronous DRAM (SDRAM) “synchronizes” the memory speed with CPU clock speed so that the memory controller knows the exact clock cycle when the requested data will be ready. This allows the CPU to perform more instructions at a given time. Typical SDRAM transfers data at speeds up to 133 MHz.
•  Rambus DRAM (RDRAM) takes its name after the company that made it, Rambus. It was popular in the early 2000s and was mainly used for video game devices and graphics cards, with transfer speeds up to 1 GHz.
• Double Data Rate SDRAM (DDR SDRAM) is a type of synchronous memory that nearly doubles the bandwidth of a single data rate (SDR) SDRAM running at the same clock frequency by employing a method  called "double pumping," which allows transfer of data on both the rising and falling edges of the clock signal without any increase in clock frequency.