1.1.3 Input, output and storage Flashcards
What is input?
Entry of data
What is output?
Printing of data in some way.
Is sensor an input or an output ?
input
Name some outputs..
Monitor Speakers Earphones Lights Projector Printer Vibrations
Name some inputs…
Keyboard Mouse Scanner Touchscreen Microphone Webcam Gamepad Barcode Reader RFID readers Sensors
How does a barcode reader work ?
Bars and spaces represent characters, which are scanned. During scanning the laser light is either absorbed or reflected, creating an electrical signal.
How does a RFID reader work?
A number is found in the computer’s database to obtain details.
How does a digital camera work ?
Picture taken is stored digitally. The camera magnifies and focuses while CCD with transistors creates an electrical signal depending on light intensity.(TRANSISTOR IS A PIXEL)
What are the three types of printers?
LASER
THERMAL
PLOTTER
What does ROM stand for ?
Read Only Memory
Characteristics of ROM…
Data stored cannot be altered
Non-volatile
Contains BIOS
What does ROM do and what does it use to do that?
It is used to boot up systems with BIOS.
What does non-volatile mean?
Doesn’t lose data when power is lost
What does volatile mean?
Loses data when power is cut.
What does BIOS do?
Its a bootup program that checks computer’s functionality. It performs check using bootup loader and gives control to the OS.
What does RAM stand for ?
Random Access Memory
What does RAM do?
Stores working programs and applications
Characteristics of RAM?
Can be accessed and data can be altered at any time
Volatile
OS needs to be copied into it to run
Directly written to and read by the processor
What is DISC THRASHING?
The process of having to move between RAM and secondary memory constantly, slowing down the computer - this happens with virtual memory.
What is virtual memory?
Part of the hard drive used as an extension of RAM.
When is virtual memory used?
When RAM is full, so that wanted programs can keep on running.
What needs to happen before a program from virtual memory is opened?
The data of that program needs to be copied back into RAM.
How can we overcome the need for virtual memory ?
QUIT PROGRAMS
ADD RAM
What is paging?
A memory managment scheme by which the computer stores and retrieves data from secondary storage. That data is read in PAGES, which are all equal.
What is secondary storage?
A hard disk or any device that stores information permanently and is not immediately accessed by the processor.
What are the three types of secondary storage ?
Magnetic
Flash
Optical
