Unit 1 Flashcards
(25 cards)
What is a PC, and its 5 main functions?
An assembly of electronic modules that interact with software to create, modify, transmit, store, and display data.
What is the difference between digital and analog?
Digital electronics use on and off conditions; there is no in-between. Either there is full voltage or none
Ex: a flashlight
Analog electronics use and produce varying voltage levels
Ex: a dimmer switch
What are the types of data?
- letters (text)
- numbers
- sounds
- images
How is data represented electrically within a computer?
High and low voltages represent data.
These high and low pulses create a digital signal
What is a digital signal?
High and low voltages represent data in a computer. These voltages are sent as pulses. These high and low pulses are called a digital signal.
Digital signals are ways that data is transmitted
What is the binary system?
- a system that represents data in a computer using the numbers 0 and 1
- base 2
- Good to represent digital electronic systems (0 is off, 1 is on)
- Similar to morse code
What does a computer do with data?
Stores, manipulates, and displays data.
What is the hexadecimal numbering system?
- base 16 (0-9, A-F)
- This system best matches the hardware system of most computers (data lines in a computer are 8, 16, 32, or 64 lines wide)
Why/when is the hexadecimal system better than the binary system?
The binary system’s numbers are too long and awkward for analog electronics. The hexadecimal system takes up less space
What does ASCII stand for?
American Standard Code for Information Interchange
What is the ASCII system?
- It was the first attempt to standardize computer character codes among the varieties of computer hardware and software
- a 7-digit (7-bit) code BUT there are several different 8-bit extended versions
- A 7-bit code can represent 128 values, and the 8-bit code can represent 256 (double)
- The 8 bit code can represent enough to include the characters used in the English alphabet, as well as some non-English characters, the 10 decimal digits, the other characters usually found on a keyboard, and many special characters not included on a keyboard such as
mathematical symbols, graphic symbols, additional punctuation marks, and other symbols.
What are the limitations to the ACSII system?
- it does not allow for certain unique characters to be transmitted; variations of fonts, bold, italics, or underlined letters are sometimes not allowed (for example)
What is cache memory?
A group of fast memory circuitry located on or near the Central Processing Unit to help speed up processing.
What is UNICODE?
- Quickly replacing ASCII
- a universal coding system designed to represent text-based data written in any ancient or modern-day language
- 1- 4 bytes (8 to 32 bits)
- It can represent over a million characters, which is more than enough unique combinations to represent the standard characters in all the world’s written languages, as well as thousands of other symbols and signs
- The most recent version of Unicode is Unicode 6.0
What is the definition of a bit?
A bit is short for BINARY DIGIT. It is a single binary unit of 1 or 0
What is a byte?
A byte is equal to 8 bits
What is a word?
A word is the total amount of bytes a computer can process at one time
What is serial and parallel data transfer?
These are the two modes by which data is transferred on a computer
What is the difference between serial and parallel data transfer?
Serial: When data is sent through a port, one bit at a time in successive order
EX: Keyboard and mouse
Parallel: When more than one bit is sent side-by-side at the same time. Usually, more data can be transferred at a time through a parallel port than a serial port
EX: Data is transferred in parallel on the computer bus system between devices such as the HARD DRIVE
How are bits and bytes represented?
Bits: b
Bytes: B
Bit (b)
Byte (B)
Kilobyte (kB)
Megabyte (MB)
Gigabyte (GB)
BBKMG
What is a bit?
The smallest unit of data a computer can process and store
What is the downside of parallel data transfer?
- Maybe too much interference, affecting the signal transfer (unreliable)
- When frequency is increased with the parallel transfer, there is the creation of a magnetic field around the pulses which could also cause interfearance
What are ways that computers process data?
- sorting items
- comparing and locating data
