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102 Cards in this Set
- Front
- Back
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what is a computer |
an electronic device which is capable of receiving information ,forms a sequence of operation, produces a result |
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what is computer science |
the study of the principles and use of computers |
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what is an output |
the output is the stage where the information obtained via processing is presented in a suitable format |
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what is storage |
where data is held. may be saved to come back to at a later date, may be an output you want to keep. |
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what is the architecture of a computer |
the internal, logical structure and organisation of the computer hardware |
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advantages of the VON NEUMANN ARCHITECTURE |
area efficient but requires higher bus bandwidth because instructions and data must be complete for memory |
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advantages of the HARDVARD ARCHITECTURE |
coined to describe machines with separate memory’s, speed effiecient, increased parallelism |
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what is a computer system |
a computer system is one that is able to take a set of inputs, process them and create a set of outputs, this is achieved by a combination of hardware and software |
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what is software |
programs and applications that we cannot touch |
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what is the role of an input |
the role of an input in a computer is provided by data for further processing |
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what is the process |
processing is the stage where the input data is manipulated in order to produce meaningful information. It can include a number of stages such as sorting and searching |
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what is a general purpose computer |
this generally refers to those systems that can be programmed to perform a wide range of tasks. the typical desktop system, tablet or laptop device can be programmed to perform multiple tasks. they can be used for a wide range of applications |
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what is a dedicated system |
these are produced to perform a single function or set of instructions it is not capable of performing any other tasks |
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what is a control system |
these are designed to control machinery and probably provide limited output for humans to respond to they are manufacturing process. industrial robots are an important application of the control system |
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what is an embedded system |
a computer that forms part of an electronic device they are found in many household devices such microwaves and telephones |
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what are advantages of embedded systems |
they are created to only serve a single purpose which means they are smaller and it wouldn’t be as expensive. they are ready programmed from the factory. they are very low powered |
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what is firmware |
the software on a device. it is usually for very specialised tasks and doesn’t usually contain an operating system |
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what is inside the cpu |
it contains the control unit, the ALU and cache memory along with billions of transistors |
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what is the cpu’s hat is t |
the central processing unit carries out all of the processing for the computer system by following the instructions given to it |
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what is the processor speed measured in |
hertz |
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what is clock speed |
number of cycles per second |
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what does GHz mean |
Hertz |
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what is cache |
it is very fast memory in the cpu, it’s slower than the registers but faster than ram. the cache acts as an intermediary between the processor and the main memory (ram) it stores regularly used data so that the cpu can access it quickly next time it is needed. it has a very low capacity |
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what is a data bus |
it carries data between cpu and memory(bi-directional,data can be read/written to |
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what is a control bus |
it carries control signals around the cpu and memory |
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what is an address bus |
it carries memory addresses for locations to be read from or written to |
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what is level 1 cache |
it is the quickest but has low capacity (often located on the cpu) |
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what is level 2 cache |
slower than level 1 but can hold more ( often part of the cpu module) |
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what is level 3 cache what is |
even slower than level 2 but can hold even more (further away from the cpu on the motherboard) |
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how does clock speed affect the performance of the cpu |
doubling the clock speed will double the number of instructions executed per second |
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how does cache size effect the performance of the cpu |
increasing the cache size will reduce the number of memory to disk transfer and this may speed up the processing of these instructions |
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how do cores effect the performance of the cpu |
quadrupling the number of cores may quadruple the number of instructions executed per second |
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what are the two main components of the processor |
the ALU and CONTROL UNIT |
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what is the ALU |
it carries out all the calculations and logical decisions required by the programme instructions (for example addition, subtraction and comparisons such as equal to, greater than or less than |
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what is the control unit |
the control unit is responsible for decoding instructions and sending out signals to control how data moves around the parts of the cpu and memory to execute these instructions (the control bus contains a control line for right instructions ) |
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how do control busses work |
control signals are sent along the control bus. this instructs which was data will be travelling to and from memory |
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how do address busses workwear is |
it carries addresses from the processor to main memory or other I/O devices it is one directional the processor generates an address all data/instructions are returned to the address bus |
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what is a register |
a register is a memory location within the cpu and can be accessed very quickly |
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what is a programme counter (PC) |
it stores the location of the next instruction in a program to be executed |
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what is a memory address register (MAR) |
it stores the location for the data to be fetched from or sent to memory |
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behe |
nene |
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name five registers |
•memory address register •accumulator •memory data register •current instruction data •program counter |
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what is the current instruction registers (CIR) |
they store the next instruction ready to be decoded |
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what is the memory data register (MDR) |
it stores all the data that has been fetched from, or is waiting to be sent to memory |
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what is the accumulator (ACC) |
it stores the results of any arithmetic or logic operations carried out by the ALU (maths) |
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what is the hardware within a computer system or smartphone which carries out instructions of a computer program |
the cpu |
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what are the three main components of the CPU |
•control unit •memory unit •ALU |
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when we are talking about a computer system what is memory |
a temporary storage |
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what three things might you find stored in memory |
instructions, commands and the operating system |
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when referring to computer memory what is meant by random access |
you can write anywhere in that space at any time |
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what does 3MGz mean |
3 billion cycles per second |
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who might use flash memory and why |
anyone who needs to transfer data from one place to another |
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what type of memory does a USB stick use |
flash memory or solid state |
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what is flash memory also know as |
solid state memory |
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what does the SD stand for in SD card |
secure digital |
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what type of memory is used in smartphones and tablets |
flash memory |
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what does the RW stand for in DVD-RW |
re-writable |
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what is the difference between DVD-R and DVD-RW |
DVD-R can only be written to once |
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what is a solid state drive |
a form of flash memory, portable storage that does not use magnetic tape |
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what is cloud storage |
online storage |
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what is an advantage of cloud storage |
it’s cheaper and automatically backed up meaning it’s secure it also needs a password |
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what is a bit |
a single 1 |
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what is a disadvantage of cloud storage |
it relies on the internet and its speed depends on the internet connection speed |
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do input devices deal with analogue or digital data |
analogue |
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name two features of a hard drive |
large capacity , fairly cheap , magnetic storage , non portable |
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name two features of CD-ROM |
small and portable , can be used in most devices , read only so can not be copied over , small capacity |
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name a feature of a solid state drive SSD |
very portable |
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give an example of magnetic storage |
hard drive, magnetic tape |
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state two functions of the operating system |
provide a user interface provide a platform for applications to run perform a platform for applications to run preform memory management perform disk/file management |
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name two different operating systems |
windows , IOS , android |
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name two utility programs and their uses |
system clean up- searches for and deletes files/programs which are no longer used automatic update- checks on the (software manufacturers site on the) internet for newer versions of programs which are installed disk defrag- cleanup of the hard drive , move files , anti virus |
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why would a company need custom written software |
if software does not exist to do the job the company wants or if the software that does exist doesn’t do exactly what they need |
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what is a byte |
8bits |
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what do we mean by of the shelf software |
software that is available in shops |
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what are two features of open source software |
it is free , lots of people contribute to it , doesn’t need a licence. |
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what is a pixel |
the smallest element of an image , dots that make up an image on a screen |
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give an example of met data stored with an image |
height , width , resolution , colour depth , date it was produced |
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what are the two types of memory |
primary and secondary storage |
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what is RAM |
random access memory is used as the main memory in a computer and it can be read and written to, when a program is loaded , it’s loaded from secondary storage (such as a hard drive) into the ram , so that the cpu can access the program instructions and associated data ram is required to boot a computer because the boot information is translated from secondary storage to ram to turn the computer on |
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why would a company need custom written software |
if software does not exist to do the job the company wants or if the software that does exist doesn’t do exactly what they need |
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what is faster ram or cpu cache |
cpu cache however ram is a lot faster than secondary storage |
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what will happen if you don’t have enough ram |
your computer may run slowly |
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what might happen if you upgrade your ram |
you will be able to run more programs and it will make your computer quicker |
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how many bytes are in a kilobyte |
1024 |
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what happens if your computer already has a lot of ram and you add more to it |
your computer may run no different to beforehand |
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what is DYNAMIC RAM |
this has a single transistor and a capacitor that can hold a charge of a few milliseconds to represent one bit |
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what is STATIC RAM |
this is more complex with four or five transistors wired together for each bit. this means it can maintain data without the need to be refreshed every few milliseconds (provided there is a power source) •expensive , faster access to data •static ram is ideally used for cache memory |
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gg |
hh |
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how many kilobytes are in a mega byte |
1024 |
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how does having more ram improve the performance of a computer |
it can load more programs and data at the same time |
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name the type of secondary storage that is built into a computer system |
hard disk drive, magnetic hard disk |
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what is DYNAMIC RAM |
this has a single transistor and a capacitor that can hold a charge of a few milliseconds to represent one bit. in order to maintain the charge in the capacitor, this type of ram must be refreshed often |
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what is STATIC RAM |
this is more complex with four or five transistors wired together for each bit. this means it can maintain data without the need to be refreshed every few milliseconds (provided there is a power source) •expensive , faster access to data •static ram is ideally used for cache memory |
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what does BIOS stand for |
basic input output system |
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where does rom copy the operating system to |
ram |
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what is virtual memory |
virtual memory is secondary storage used as extra ram. computers have limited amounts of ram, as applications are opened , ram fills with data , when ram is full , the computer needs somewhere else to put application data. |
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when would virtual memory be needed |
if there are too many applications open at once or it is particular memory intensive application being used |
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what happens when the cpu needs to read data stored in virtual memory |
it must move the data back to the ram this then slows the transfer rate |
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what is firmware |
permanent software programmed into ROM |
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what is paging |
in computer operating systems , paging is a memory management scheme by which a computer stores and retrieves data from secondary storage |
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what is disk thrashing |
when a computers virtual memory subsystem is in a constant state of paging |
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heh |
jrn |
