Chapter 3 Flashcards
What are the two broad components of a computer system?
Hardware and Software
What does hardware refer to in a computer system?
The physical units or machines that make up the computer configuration
What are the three areas into which hardware can be divided?
- Central Processing Unit (CPU)
- Main Memory
- Peripheral Units
What is the Central Processing Unit (CPU) commonly referred to as?
Processor
What are the two sections of the Central Processing Unit?
- Control Unit
- Arithmetic and Logical Unit (ALU)
What is the role of the Control Unit?
Supervises the execution of instructions in the correct sequence
What are Registers in the context of the Control Unit?
Special storage locations used by the control unit
List the operations carried out by the Control Unit while executing an instruction.
- Obtain address from the program counter
- Copy instruction into the Instruction Register
- Increment the Program Counter
- Decode the instruction
- Execute the instruction using the ALU
What does the Arithmetic and Logical Unit (ALU) do?
Performs arithmetic and logical operations on operand inputs
What types of operations can the ALU perform?
- Arithmetic operations (addition, subtraction, multiplication, division)
- Logical operations (comparison, shifting)
What is the main memory also known as?
Immediate Access Memory or Random Access Memory (RAM)
What does the main memory hold?
The program being executed and the data to be processed
What is Read-Only Memory (ROM) used for?
Holding short programs that help to start up the system
What are the three types of peripheral units?
- Input Devices
- Output Devices
- Auxiliary Storage Devices
What purpose do input devices serve?
Allow data to be read into the CPU from the outside world
Give examples of input devices.
- Punched Card Reader
- Paper Tape Reader
- Keyboard
What is the function of output devices?
Permit results of processing to be transferred from the CPU to the outside world
List some examples of output devices.
- Printers
- Visual Display Unit (VDU)
- Graph Plotters
What are auxiliary storage devices also known as?
Backing storage, external store, or secondary store
What is the main advantage of auxiliary storage?
Higher storage capacity with lower costs compared to main memory
What is Magnetic Ink Character Recognition (MICR)?
A method where human-readable characters are printed with magnetizable ink
What does Optical Mark Recognition (OMR) entail?
Making small marks on documents that are interpreted by a computer program
How does Optical Character Recognition (OCR) work?
Scans characters with light and converts brightness variations into electrical signals
What is the primary output from printers referred to as?
Hard copy of data
What is the role of a Visual Display Unit (VDU)?
Displays processed data/information before it is sent to the printer
What is Computer Output on Microfilm (COM)?
A method of storing large quantities of data in readable form on photographic film
What is the main advantage of microfiche over microfilm?
More compact and easier to update and view
True or False: Semiconductor memories are volatile.
True
Fill in the blank: The ALU produces outputs that represent the results of operations performed on the _______.
[operand]
What are the two outputs produced by the ALU?
- Results of the operation
- Status information sent to the status register
What is a dedicated graph plotter used for?
Output of graphical information on large and small computers
What type of printer is most common for human interpretation?
Printers that produce output on sheets of continuous stationary
Name the two categories of printers.
- Impact Printers
- Non-Impact Printers
What do impact printers use to print characters?
Impact onto paper by means of an ink ribbon and print wires or hammers
Examples of impact printers include:
- Line Printers
- Daisy Wheel Printers
- Dot Matrix Printers
- Teletypes
- Typewriters
How do line printers operate?
They print a line at a time using rows of character sets on a drum or a chain
What is a daisy wheel printer?
A printer that prints a character at a time by impact using a plastic wheel with characters on spokes
What is the print quality of a dot matrix printer?
Not usually of letter quality type
What distinguishes non-impact printers from impact printers?
Non-impact printers work without something hitting the paper
How does an ink-jet printer function?
It squirts a jet of ink on the paper to form dots that make up characters
What does a thermal printer use to print?
Very small wires to burn a special paper
What is a laser printer?
The latest printer technology that prints a full page at a time using a principle similar to photocopying
Define graphics in the context of computer usage.
Pictures including graphs, diagrams, charts, and moving images on a video screen
What is the purpose of a light pen?
To display, modify or detect images on the screen in CAD applications
What is a graphic table also known as?
Digitizing table
What is the function of a mouse in computer graphics?
It can be moved to plot images in defined locations on a screen
What are auxiliary storage devices?
Cheaper forms of storage that can store a lot of information until needed
Common types of auxiliary storage devices include:
- Magnetic disks
- Tapes
What is a Winchester disk?
An in-built auxiliary storage media in the computer system with greater storage capacities
What are soft disks commonly referred to as?
Floppy disks
What is the capacity of an 8-inch floppy disk?
Approximately 250k bytes for single sided double density, 500k bytes for double density
What are optical discs used for?
Mass storage devices that record and read information using a laser
What is a CD-ROM?
A disk that can store as much as 660 megabytes of information, read-only
What does WORM stand for?
Write Once/Read Many
What is a rewriteable magneto-optical disk?
A disk that can be erased and written over using a high-powered laser beam
What are integrated discs?
Discs stored in the same cabinet as the processor and memory
