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storage types, COMPUTER SCIENCE - Coggle Diagram
storage types
types of secondary storage
optical
Optical storage is very portable and cheap as it can be brought in the form of a CD, which can easily have data copied onto it and read with relative ease
Optical storage: Optical devices use a laser to scan the surface of a spinning disc made from metal and plastic. The disc surface is divided into tracks, with each track containing many flat areas and hollows. The flat areas are known as lands and the hollows as pits.
SSD
Solid state drives are also very durable due to their absence of moving parts, this further means that any data stored on devices can be easily copied and have minimal chance of corrupting
Most solid state devices use a type of flash memory to store data indefinitely. They tend to have much faster access times than other types of device and, because they have no moving parts, are more durable.
Magnetic
Magnetic devices also have much higher capacity due to their form of storage, this makes them ideal for people who have large amounts of files to store
Devices such as hard disk drives use magnetic fields to magnetise tiny individual sections of a metal spinning disk. Each tiny section represents one bit. A magnetised section represents a binary '1' and a demagnetised section represents a binary '0'.
primary storage
This include RAM and ROM, these are Read Only Memory, and Random Access Memory.
In these options we can see that Ram is clearly volatile, whilst Rom is not, and that neither is very portable whilst Ram can both read and write in the memory, rom can only read, they are both rather slow, however, Rom is significantly faster then ram
COMPUTER
SCIENCE
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fILE SYSTEMS:
A file system is created to organise files and directories.
This gives programs a consistent way to store and retrieve data.
The OS is also responsible for the naming, sorting, deleting, moving and copying of files (at the request of the user).
Add pictures below that represent each of these responsibilities highlighted and label them.
OS
the operating system is responsible for transferring programs to and from memory.
It keeps track of memory usage, and decides how much should be given to each program.
The OS also decides what happens if there is not enough memory.
Features of the Operating System
User Interface: A user interface (UI) is provided by an operating system to allow users to interact with the hardware of the computer system. ...
Memory Management: ...
Process Management: ...
Device Management: ...
File Management: ...
Security: ...
Performance:
Common Operating Systems:
Microsoft Windows. Microsoft Windows is one of the most common graphical OS. ...
Linux. Linux is a popular operating system. ...
Android. It is one of the most common versions of the operating system today. ...
Apple iOS. After android, it is one of the most popular OS. ...
Apple macOS. ...
Solaris.
An operating system is system software that manages computer hardware and software resources, and provides common services for computer programs.
An important piece of a computer's utility software is its file management program, which manages all the files stored on its drive. Computers store all data in files, so the file management tool allows the user to browse and search the stored files.
Utility software is a program specifically designed to help manage and tune system or application software. It is used to support the computer infrastructure - in contrast to application software, which is aimed at directly performing tasks that benefit ordinary users.
The main functions of Utility Software include system maintenance, data compression, file management, and security.
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FDE (fetch decode execute)
The fetch-decode-execute cycle describes the basic operation of modern computer systems.
Programs, for example those that allow you to play a video game, use a spreadsheet, debug a program, or check your emails, are made up of thousands of instructions. To run a program these instructions must be fetched, decoded, and executed.
These stages form the fetch-decode-execute cycle — or fetch-execute cycle or instruction cycle — because they are repeated over and over again for every instruction of every program that is run inside a computer.
The cycle
Fetch
The instruction is fetched from main memory and stored in the processor. The control unit can then access the instruction so that it can be decoded and executed.
Decode
The instruction needs to be decoded before it can be run. This is the process the control unit uses to work out what signals to issue to the other components for the instruction to be executed.
Execute
The control unit will send signals to the relevant components so that the instruction is carried out.
The CPU
The purpose of the CPU is to continuously fetch, read and execute instructions stored in memory by repeatedly carrying out the fetch-execute cycle. The CPU contains the Arithmetic Logic Unit and the Control Unit, in addition to several general-purpose and special-purpose registers.
in computing, an arithmetic logic unit is a combinational digital circuit that performs arithmetic and bitwise operations on integer binary numbers.
The control unit is a component of a computer's central processing unit that directs the operation of the processor
In computing, the clock rate or clock speed typically refers to the frequency at which the clock generator of a processor can generate pulses, which are used to synchronize the operations of its components, and is used as an indicator of the processor's speed.
A processor register is a quickly accessible location available to a computer's processor. Registers usually consist of a small amount of fast storage, although some registers have specific hardware functions, and may be read-only or write-only.
Embedded systems
Disadvantages
Limited user interaction
Development complexity
Limited upgradability
An embedded system is a small computer that forms part of a larger system, device or machine. It includes both hardware and software and its purpose is to control the device and to allow a user to interact with it. They tend to have one, or a limited number of tasks that they can perform.
Advantages
Flexibility in design
Cost efficiency
Real time performance
Low power consumption
Perform specific actions
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Levels of language
Low-level languages can offer several advantages over high-level languages in certain scenarios. For example, they can produce faster and more efficient code that optimizes the use of hardware resources and minimizes the overhead of abstraction layers
Machine Code
Machine code is made up of the data that is being worked on and a list of instructions that tell the processor to do something. Because everything in a computer is stored as binary (1s and 0s)
Translators convert code into
binary for the cpu to execute
The main difference is that assembly language is a symbolic representation of machine language, consisting of binary code executed directly by the computer's hardware. Machine code, object code, or machine language is a collection of bits (or binary digits) to be read and interpreted by a computer.
Low-level languages also have some challenges that make them harder to use and maintain. They are more difficult to learn, write, read, debug, and update. They are less portable and compatible across different platforms and devices.
Translators are needed to translate programs written in high level languages into the machine code that a computer understands. Tools exist to help programmers develop error-free code.
Compiler
a computer program that changes instructions into machine language
Compiler: A compiler translates code from a high-level programming language into machine code before the program runs. Interpreter: An interpreter translates code written in a high-level programming language into machine code line-by-line as the code runs.
A computer system can have a compiler, but it is not pre-installed universally. While some systems may come with a compiler installed, it's not necessarily standard. A compiler is a special type of software that translates programming code written by programmers into binary code that a computer can execute.
A compiler is similar to an interpreter. However, a compiler is faster than an interpreter and translates the entire file at once. An interpreter reads the source program line by line and, therefore, is a slower process. TurboC++ and Keil are two specific examples of commonly used compilers.
Translator
and interpreter
An interpreter translates source code into object code one
instruction
at a time. It is similar to a human translator translating what a person says into another language, sentence by sentence, as they speak. The resulting object code is then executed immediately. The process is called
interpretation
.
Interpreters have several advantages:
Instructions are executed as soon as they are translated.
Since instructions are executed once translated, they are not stored for later use. As a result, interpreters require less available memory.
Errors can be quickly spotted - once an error is found, the program stops running and the user is notified at which part of the program the interpretation has failed. This makes interpreters extremely useful when developing programs.
Interpreters also have several disadvantages:
Interpreted programs run more slowly as the processor has to wait for each instruction to be translated before it can be executed.
Additionally, the program has to be translated every time it is run.
Interpreters do not produce an executable file that can be distributed. As a result, the source code program has to be supplied, and this could be modified without permission.
Interpreters do not optimise code - the translated code is executed as it is.
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Binary
Made up of 0's and 1's
1's and 0's are like on and off
Computers language
128 64 32 16 8 4 2 1
You put the 1's and 0's on this chart and add up all the numbers above the ones. e.g. 00010101 = 21
A binary number is a number expressed in the base-2 numeral system or binary numeral system, a method of mathematical expression which uses only two symbols: typically "0" and "1". The base-2 numeral system is a positional notation with a radix of 2. Each digit is referred to as a bit, or binary digit
Hexadecimals
Like denery
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