Historical Development of Databases Hierarchical Database Model A data model in which data is organized in a top-down, or inverted tree structure with lower level records subordinate to higher-level records A lower level record is called a child and a higher level record is called a parent Each parent record can have many child records,…
As technology becomes more and more advanced, developments are being made in the world faster than ever. The question is, are these changes more beneficial or detrimental? These modern advancements are in no way one hundred percent beneficial, but they have, truly, improved the quality of people’s lives. Some examples would be: machine-made instruments after…
Computer and telephone networks inflict a gigantic impact on today’s society. From letting you call John in Calgary to letting you make a withdraw at your friendly ATM machine they control the flow of information. But today’s complicated and expensive networks did not start out big and complicated but rather as a wire and two…
Microprocessors are defined as a computer’s central processing unit, usually contained on a single integrated circuit (Wyant and Hammerstrom, 193). In plain English this simply means that a microprocessor is the brain of a computer and it is only on one chip. Winn L. Rosch compares them to being an electronic equivalent of a knee-joint…
Before gophers, hypertext, and sophisticated web browsers, telnet was the primary means by which computer users connected their machines with other computers around the world. Telnet is a plain ASCII terminal emulation protocol that is still used to access a variety of information sources, most notably libraries and local BBS’s. This report will trace the…
A virus is a program that copies itself without the knowledge of the computer user. Typically, a virus spreads from one computer to another by adding itself to an existing piece of executable code so that it is executed when its host code is run. If a virus if found, you shouldn’t panic or be…
In the 1960’s, the use of main frame computers became widespread in many companies. To access vast amounts of stored information, these companies started to use computer programs like COBOL and FORTRAN. Data accessibility and data sharing soon became an important feature because of the large amount of information recquired by different departments within certain…
Central Parts Motherboard The main circuit board of the computer to which all components are attached. It contains metal tracks through which electricity flows, electronic devices, and transistors that control the flow of electricity. (The motherboard is like a city, with highways and streets that connect the buildings together.) CPU (Central Processing Unit) Also called…
There have been many different inventions that have led us to our modern day computer Original computers were non-electronic devices used simply to tally and calculate numbers As time progressed more and more improvements were added to these computers which have led to the modern day computers that we have There have been several different…
Comments Documentation Comment Statement Comments /** * */ E.g., /** This is a sample comment * that would span * multiple lines */ // // This is a sample single line comment Primitive data Type int E.g., int sumOfNumbers; double E.g, double average; char E.g., char singleChar; boolean E.g., boolean isBig; Declaring Variables <Visibility> <type> …
STORING VALUES IN THE COMPUTER’S MEMORY A variable is a named storage place in memory. There are 2 kinds of memory: Temporary memory (RAM), holds the work your computer is currently processing. Permanent memory (disk memory), holds data after you switch off your computer. A variable is stored in temporary memory. Therefore, it only exists…
An array is used to store many similar types of data using a single variable name. The array should be pictured as a container with many compartments. The container has one name, but each of the compartments is numbered. In order to refer to the value stored in a single compartment, we must use the…
Counters There are a number of times in computer programming where the user needs to determine the number of times a certain event occurs. Examples: Counting the number of times a person enters a number (in order to find the average) Determining how many rolls of two dice were needed before a 6 was rolled…
The DO … LOOP is used to repeat a block of statements while a condition is true OR until a condition becomes true. This type of loop is required when you don’t know how many repetitions you will need before you start. When you know the number of repetitions, you use a FOR .. NEXT…
Recall: Computers communicate using binary Therefore, computers do NOT process information using characters (e.g. letters). Each letter or character has a number representation that the computer uses to refer to the character. ASCII: American Standard Code for Information Interchange ASCII is a code for representing English characters as numbers. The ASCII numbers range from 0…
The Internet Large sprawling network on a global scale. A very large sprawling Wide Area Network A network of many networks A little History… 1960’s Advance Researh Projects Agency (ARPAnet) is a system of linked mainframes Developed by military to ensure communication in times of crisis 1980’s MILNET splits from ARPAnet to form the Internet…
Definition In a network, a communication channel is a physical path the transmission signals travel. It is the path information travels from computer to computer. How do the computers in a network “connect” to each other. The 5 communication channels twisted-pair cables coaxial cables fiber optic cables terrestrial stations communication satellites Twisted pair cables Signals…
Definition A computer network is a number of computers linked together to enable them to share computing resources. Networks can be permanent (via cables) or temporary (via modem) The sharing of resources through a network can also be local or global Networks allow different types of computers to communicate. Benefits Information can be accessed in…
Software is the programs, routines, and symbolic languages that control the functioning of the hardware and direct its operation. Types of Software Retail Software type of software is sold off the shelves of retail stores. includes expensive marketing and packaging designed to catch the eye of shoppers generally more expensive OEM Original Equipment Manufacturer designed…
Motherboard The motherboard is the main circuit board of a computer. EVERYTHING in a computer system is connected to it!!! Produced in a variety of sizes (a.k.a. form factor) Components The following are components that are typically connected to a motherboard CPU Hard Drive Optical Drive (DVD, CD, etc)þ RAM Video Card Power supply A…