Explain the roles of computers and where they can be found
- Computers are found everywhere
- Not one industry can operate without a computer
- They can be found in banks, military aircraft, automobiles, televisions, communication systems, home appliances, satellites, submarines, and police stations
Explain the differences within computers
Computers aren’t just the ones we use but they can vary in size from a small microprocessor that can be found in a coffee pot to huge mainframe systems used for research and government systems
Why are computers supposed to be understood and how are they understood?
- Computers may be difficult but to be understood then you have to understand the interaction of hardware and software, grasp different operating systems and recognize different areas that can be upgraded and compatibility issues
- By knowing which part is not working then it is an easy task to replace the part
- The challenge is by determining the problem and whether it is software or hardware related
Explain a digital system and give examples.
- Digital: system represented by a simple switch where two conditions (on and off) are present
- The switch controls all the power to the lamp which can be either on (full voltage) or off (no voltage)
- No other electrical condition can be be put into this simple circuit
- Digital electronics in computers use these on and off conditions
- Examples: streetlight, car horn, flashlight
Explain analog electronics and give some examples.
- Analog electronics: use and produce varying voltage levels
- Uses a dimmer switch
- The intensity of the lamp varies as the dimmer switch is turned
- The dimmer varies the amount of electrical energy the lamp receives
- Ex. Automobile gas pedal, wind speed, slide trombone, drum
What are digital circuits combined with and how do people repair it?
- Computers have very complex digital circuits that are combined into modules such as circuit board cards
- PC technician is responsible for replacing the module not repairing digital circuits
- To repair a PC, lots of background on electronics isn’t needed
- If a capacitor breaks, the whole circuit breaks
What is a computer and the 5 main functions of a typical computer?
Assembly of electronic modules that interact with computer programs known as software to create, modify, transmit, store and display data ← 5 main functions of a typical computer
Why aren’t computers intelligent?
- Computers are NOT intelligent, only processes and stores data
- Computers cannot think, they can only be programmed
What are 3 ways that computers process data?
Processing data includes sorting items, comparing and locating previously stored data ← 3 ways computers process data
What percentage do computers make of the world?
Computers make up 30% of world, the embedded systems like electronic cars make up 70% of market
What is data and 3 forms of it?
Data is information that comes in many forms such as text, graphics and sounds ← 3 forms of data
What is a digital signal?
A digital signal is a signal that represents data as a sequence of discrete values. A digital signal can only take on one value from a finite set of possible values at a given time. Like in binary form
Digital signals, however, remain clear despite interference because they only need to distinguish between ones and zeros.
How is a digital signal created and what do these pulses do?
- Data in the computer is represented electronically as high and low voltages that are pulsed through the system which creates a digital signal
- These pulses of electrical energy can do many things such storing data in memory chips, or hard drives
- When data is written to a hard drive, the electrical pulses are converted to magnetic patterns on the surface of the disk
- A digital signal translates information using 1s and 0s for reliable data storage in electronics.
- Can store in I-cloud, microsoft cloud and google drive
What do digital patterns represent?
Some of the digital patterns represents words, pictures and sounds and others represent commands like load file, find file and save file
What can computers only do?
Computers can only manipulate, store and display data
How can data be expressed?
Data can be expressed in different forms such as voltage levels, numeric systems like binary and hexadecimal and symbolic codes.
Why should data be represented in the easier form?
- The form in which data is represented in should be the one that is easiest to grasp for the given material
- Ex. It is easier to express memory location as hexadecimal values rather than binary even though memory location can be expressed in either value
- Computer technicians chould be clear on all of this
What is the binary system and what does it consist of?
Consists of 0 and 1
Perfect numbering system to present digital electronic systems
Two states (on and off)’
The 1 and 0 also represent data stored on disks and memory chips
What is the binary system compared to?
The binary is compared to a switch where 1 is full voltage or on and 0 is no voltage or off
Binary uses patterns as switches
How is Morse Code similar to the binary system?
It may be too simple of a system to represent data but it can be compared to Morse code
Morse code has two states: a short beep and long beep (dot and dash)
The become combined to represent alphabet and numbers
Morse code transmits information worldwide
How is the binary system present in the fax machine?
Similar to digital electronic, graphics are transmitted using fax machine where light and dark areas are represented by full voltage or no voltage, a certain number is assigned to each pixel to determine level of darkness in the picture
What base is binary code and explain it.
- Each digit represents an increasing amount of power with a base of 2
- It goes from right to left with 20, 21…
- This is evaluated and the 1’s in the pattern, their values with base 2 become added together
- (ASCII) codes. Each letter consists of eight numbers. Uppercase letters start with 010 and lowercase letters start with 011. The letter “a” is 01100001.
What is the hexadecimal system?
Base 16
Uses 16 characters
Numerals 0-9 from the decimal number system and letters A-F that represent numbers
A = 10, B = 11, C = 12, D = 13, E = 14, F = 15 → 16 isn’t included because 0 is considered that value
Why is the hexadecimal system useful for?
- This system is very useful because binary numbers are long and awkward to express computer values like memory locations so hexadecimal numbers are used instead because they take up less space
- The more bits there are in a binary number, the harder it makes for a human to read. Numbers with more bits are more prone to errors when being copied.
