SDD Notes lol Flashcards
Define: the ALU
the [Arithmetic Logic Unit] deals with all calculations and logic decisions
the more bits used to represent each character;
the larger the file size will be
parts of the processor: (3)
registers
the ALU
the control unit
Define: array
arrays store multiple values of the same data type
is a gif standard file format?
yes
Compilers: translate speed
all at once - faster
largest unit of storage?
Petabyte (Pb)
example of a logic error
trying to calculate average from sum of 4, 5 and 6 but instead of the output being 5 it is 15
Define: Interfaces
an interface allows two devices to communicate with each other
equals
=
Integer
Whole Number
how does using a breadcrumb aid navigation
helps user view path taken to reach this page OR
useful to retrace steps and go back to previous pages OR
useful in indicating section of current page to orientate user
what is Unicode mainly used for
storing languages with very large character sets
state the data structure that would be used to store a list of Price values
examples of Price values: 34.3, 66.1, 92.3
an array of real numbers
how many bits does Extended ASCII use per character
8-bits; 2^8
Define: graphical object
An object that can be placed on the user interface that can contain a picture
Interpreters: when does the program need to be translated
every time the program is run - slower
Define: pre-defined functions
Code that has been created to perform a certain action which does not need to be programmed but can be used by the programmer
explain how a search engine is used to produce a list
through a search that matches user searched keywords then searches a database of known pages.
Python expression(s) to assign values to variables
declaring it: counter=0
requesting input: age=input(“How old are you?”)
changing an existing value: total=total+mark
real numbers are stored using
a mantissa and exponent
Define: Machine Code
the language that a computer understands which is made up from a combination of 1s and 0s
why is file compression used before transferring files to cloud storage
so the upload / transfer is faster OR
so more files can be stored
Compilers: when does the program need to be translated
only once as the translated code can be saved - faster
purposes of using an interface (3)
temporary storage of data handling of status signals data conversion - serial to parallel voltage conversion communication between devices
what is the domain name of
http://www.sqa.org.uk/sqa/41288.html
(www.)sqa.org.uk
If a number begins with a 0 does it need to be declared as a string?
yes
why must high level languages be translated into machine code in order for them to be run?
computer systems only speak machine code so out programs must be translated into machine code I order to have our instructions carried out.
how many bits does ASCII use per character
7-bits; 2^7
Features of a web browser (5)
shortcuts favourites bookmarks refresh home search box address bar stop button tabbed browsing customisation of toolbars change default homepage
an algorithm to check that the data that is inputted can be accepted
Get input from user
While input = incorrect
Display error message
Get input from user
End whilevectors graphics are stored as
individual objects with attributes such as StartPoint X, StartPoint Y, EndPoint X, EndPoint Y, line thickness, line colour etc.
pro of using bitmapped graphics
realistic
not equal to
!=
Fixed loops will
always execute a set number of times
more than or equal to
> =
what makes a program more readable? (3/4)
internal commentary
meaningful identifiers
indentation and whitespace
Interpreters: translate speed
one line at a time - slower
Will your program run with a logic error?
yes but will display an unexpected output
basic computer architecture: (4)
the processor
main memory
buses
interfaces
1D Arrays are declared with
[ ]
square brackets
characters can be stored using what formats? (3)
ASCII, Extended ASCII and Unicode
Define: the registers
fast access temporary storage locations
con of using bitmapped graphics
loses quality when scaled up
objects cannot be overlapped
name the two translators
compiler & interpreter
Define: ROM
[Read Only Memory] cannot be altered and is not lost when the computer is turned off
bitmapped graphics are stored as
an array of pixels
exponent
deals with the range of the decimal number
borrowing someones wireless network / wifi without their permission is breaking what law
communications act
smallest unit of storage?
bit (binary digit)
Example of a complex condition
while (age>=12) and (age<=18)
whole numbers are stored using
binary
Interpreters: when are errors displayed
if an error is found the translation stops and it is highlighted - useful
Interfaces compensate for (3)
differences in data transfer speed, power usage, languages that the devices use to enable these devices to communicate with each other
Will your program run with an execution error?
yes but may crash due to unexpected input
Define: pseudocode
text representation of what your code will do
example of an execution error
contains a conditional loop with a condition that cannot be met.
Real
Decimal Number
Define: string
a variable containing a combination of letter, symbols and numbers
con of using vector graphics
unrealistic
Define: exceptional test data
data that is outwith the range that our program is expecting to be entered. This input will be rejected and inform the user why it has been rejected.
less than or equal to
<=
less than
<
mantissa
deals with the accuracy of the decimal number
Python expressions to return values using arithmetic operators
+, -, *, /, ^
Example of a simple condition
if (age>18)
why do programmers use high level language for coding instead of machine code
it is easier for humans to understand since they use everyday words like: IF, FOR, PRINT, WHILE etc.
equal to
==
Example of a pre-defined function
the Round function: number=round(number,1)
this rounds to one d.p.
what is similar to pseudocode that can be used?
graphical representation ( as in graphic as in picture )
parts of the main memory: (2)
ROM
RAM
how is a real number stored
as a mantissa and an exponent
Define: readability
how easy it is for other programmers to understand what is happening in your code
examples of interfaces
USB2.0
USB3.0
Thunderbolt
HDMI
Define: extreme test data
data that is the largest and smallest value that can still be accepted and will still produce the result we predict
Will your program run with a syntax error?
no
graphics can be either
bitmap or vector
Define: the Control Unit
it controls the order in which instructions are executed within the processor. also in charge of prioritising
Define: boolean
A variable that can only have two values, true or false
example of a syntax error
priint(“hello”)
Conditional Loops will
execute an unlimited amount of times until the condition is met
Compilers: when are errors displayed
upon completion of translation
Cause of syntax error
code isn’t formed or written properly
Python expression example to concatenate strings and arrays using the & operator
school=”Albyn”
form=”U4D”
joinedTogether=school&form
Pro of using an array
saves large amount of coding by not having to declare lots of single variables e.g. names1, names2, names3 etc.
how many bits does Unicode use per character
16-bits; 2^16
more than
>
Define: RAM
[Random Access Memory] is temporary storage where its data is lost when the computer is turned off
Define: normal test data
data that we are expected to enter and will give us the result we predict
pro of using vector graphics
allows objects to be overlapped
can be rescaled with no effect on quality of image
Ways a company should dispose of old computer systems
removing data from hard drive
using collection company
recycle individual components appropriately
dispose of dangerous elements
remember to end loops when writing pseudocode
lol
why is solid state storage more suitable for a digital camera than magnetic storage (2/3)
solid state has no moving parts
robust storage more suitable
solid state can be removed
faster transfer of data from solid state
advantages of using a tablet rather than a laptop to show people stuff at an event
simple interface for a range of users
touch screen is easy to use
more portability as it is lightweight
more robust
concerns when using free wifi
slow data transfer speed compared to wired connection
security issues
lack of coverage across area
signal interference from other devices
State the feature of HTML code that allows a webpage to be formatted.
Tags or Styles
Clicking on a “Location Map” button opens the Planet Earth Maps website in a new window. Explain why the HTML code for this link uses absolute addressing.
because it is an external link to another site/server
State the standard algorithm that is used to ensure that data entered is acceptable.
(input) validation
Reasons a webpage could be unsuitable for use on portable devices such as tablet or smartphone. (2/3)
> Navigation bar does not fit across small screen
Too many columns
Too much information for small screen >Icons too small to click on right hand side
Would take too long to load images on portable device
When buying items online, encryption is used. Explain why customers should be reassured by this feature.
Personal details transmitted in code cannot be read (by hackers). OR Keeps personal data secure/safe OR Only the company can access the encrypted data
Explain why different types of smartphone would require different versions of an app. (2)
Different types of smartphone have:
>Different operating systems on devices
>Hardware differences (resolution, dual core processor, memory etc)
What is a carbon footprint?
Carbon Footprint is the overall harmful emissions associated with a life of a product/time frame.
