Unit 3 Hardware and Software Pt. 2 Flashcards
Statement summing High and Low level languages
− The structure of language statements in a computer program is called the SYNTAX
− A programming language that uses natural language statements is called a HIGH LEVEL LANGUAGE
− When programs are written in this type of language they need a TRANSLATOR to convert them into MACHINE CODE
− A programming language that is written using mnemonic codes is called ASSEMBLY LANGUAGE language.
− This is an example of a LOW LEVEL LANGUAGE
Describe Primary Storage
− Memory that is directly accessed by the CPU
− An example is RAM / ROM
− RAM stores programs and data that are currently in use and ROM stores boot-up instructions
− RAM is volatile and ROM is non volatile
− RAM typically has more storage than ROM
− Volatile memory means data is lost if device is powered off, non-volatile is when data remains even after device is powered off.
Describe Secondary Storage
− Storage that is not directly accessed by the CPU
− An example is HDD / SSD
− Stores data / files that can be accessed at a later stage
− Non volatile
Describe why is SSD better than HDD and vice versa
SSD better than HDD:
− Faster read/write operation
− Less latency
− Produces less heat // needs less cooling
− Less susceptible to interference/magnets
− Less power consumption
HDD better than SSD
−Cheaper
− Infinite amount of read/write cycles
Describe how a SSD works
SSD
− Flash storage
− Uses transistors and controls gates
− Can be NAND/NOR technology
− Stores data by flashing it onto the silicon chips
− Controlling using the flow of electrons through transistors/chips/gates
− The electric current reaches the control gate and flows through to the floating gate to be stored
− When data is stored the transistor is converted from 1 to 0 / 0 to 1
− Some use EEPROM technology
Describe how a HDD works and benefits
− It has platters
− Platters/disk divided into tracks
− Platter/disk is spun
− Has a read/write arm that moves across storage media
− Read/writes data using electromagnets
− Uses magnetic fields to control magnetic dots of data
− Magnetic field determines binary value
Benefits:
− Has more longevity than solid state storage
− Has more read/write cycles than solid state storage
− Cheaper per unit of data
− Trusted technology used for many year
Describe how off-line storage works
How its read
− Red laser is used, laser beam shone onto disk
− Disc is rotated on a constant speed to be read
− Surface is covered in track
− Data is represented on the surface using pits and lands
− Pits represent binary valves
− Pits reflect light back differently
How data is written − Laser beam is used − Laser makes indentations on the surface of the disc − Data is written in spiral track − Pits and lands represent binary values
− It is non-volatile
− Can be easily disconnected from the computer or inserted
− It is not directly accessed by the CPU
− Suitable example e.g. CD, DVD, USB flash memory
− Portable, small
− Expensive to buy per GB
Examples of optical, solid state, magnetic storages
Optical- CD, DVD, Blu-ray
Solid state- USB flash drive (important to mention flash drive) , SD cards
Magnetic- HDD
Describe features of an operating system
− Manage input output − Multi-tasking − Loading and running of apps − Manage security − Memory management − Error handling − Human computer interface
Describe High level language
High-level
− Makes use of words close to human language
− Machine independent and portable
− Problem and logic focussed
− Needs to be translated/interpreter/compiled (to low-level for processing by
computer) // needs converting to machine code
− Hardware of computer does not matter
Benefits
− Easy to understand as its similar to human language
− Easy to debug, less likely to make mistakes
− Less time to write
− Has a great range of languages
Describe Low level language
Low level
− Closer to/is machine code
− May use mnemonics
− May need an assembler to be translated
− One line of code represents a single instruction
Benefits − Machine dependent − Have direct access to memory locations/registers − May require use of special hardware − Code runs fast
Disadvantage
−Easy to make errors and hard to understand
Examples
− Machine code
− Assembly
Statement summing up them
− The structure of language statements in a computer program is called the syntax
− A programming language that uses natural language statements is called a High level
language
− When programs are written in this type of language they need a translator to convert
them into machine code
− A programming language that is written using mnemonic codes is called assembly
language.
− This is an example of a low level language
Describe Translators
− Programs need to be translated to machine code so we have 3 types of translators
− Compiler, interpreter, assembler
−Compiler translates high level to machine code
− Interpreter translates high level to machine code
− Assembler translates low level to machine code
Describe compiler
− Translates a whole program in one go
− Produces an executable file
− All error list produced at the end
− Once program is compiled, doesn’t need to be recompiled
− One high level statement can be translated into many machine codes
− Executable file usually distributed for general use
− Executable file does not require to be re-translated
Describe Interpreter
− Translates code line by line
− No executable file produced, interpreter required every time
− Stops translation when error found, then allows you to continue from where u started
− Errors shown in real time, when found, easy to debug
− Used in developments of a program or game
