Chapter # 10
Prepared by :Sir Abdul Wajid
Users often need to transfer data
between software packages or
Until relatively recently this was difficult
to achieve, but the increasing use of
computers and the growth of ICT has
forced software designers to make this
File conversion from older to newer
versions of the software.
File conversion is an important part of computing
If you r using new software version then there is a need that this
software will read the files from the old database.
It means that old data can be converted for use on newer
This saves considerable time because it avoids users having to re-
enter existing data onto a new system.
It is always important to make sure that any new software were buy can
read your old files.
Problems might arise with file conversion if the data is very old or
is formatted for a system that not longer exists.
However, most newer version of software are usually capable of
reading data from older versions (e.g. Word97 files can be read
Most database, spreadsheet and word processing files can be read by
other packages as well .
However it is always important to check that this compatibility
between software packages and data works.
ASCII is the acronym for American Standard
Code for Information Interchange.
ASCII is a world-wide standard code for
representing characters (letters, numbers etc.)
as binary code.
Before its introduction, it was almost
impossible to transfer data between software
packages or computers.
For example the letter A has the ASCII code
0100 0001 and B is 0100 0010.
An example of ASCII
HELLO! Is represented by the following
H 0100 1000
O 0100 1111
! 0010 0001
AMERCIAN STANDARD CODE FOR
This code is representing characters ( letters,
numbers) as binary codes.
All computers can store data as ASCII code and a
file used to hold ASCII code is called ASCII file.
The 8 bit binary codes used to hold the letters of
Let suppose ASCII code of character A is
Transferring files between
The most common type of the file transfer is
between different word processors.
In large organizations people use different
versions of word processors, so there is a
need such a word processor which can be
The only way to transfer text between
different word processors is to store
everything as ASCII file.
Comma separated Variables
One common file format is “Comma
Separated Variables ” as CSV
The CSV File format is useful because it is
possible to transfer files.
Files in this format can be read by most
spreadsheets and databases.
File Handling Packages
Backing storage devices such as disk drives are able to store
files outside the CPU.
These files could be program files which holds the series of
instruction then it will perform a useful tasks.
We need to perform file processes such as deleting, copying or
If we want to say, delete or copy a large number of files then
there is a need a special software called the file packages.
A file used to hold a drawing you have drawn using a drawing
Special software is able to reduce the size of
files to about one quarter of their size.
Zip Files are often use for that purpose
You can also unzip or decompress the files.
Program and data files are often compressed
before they are sent over the internet.
It provides continuous value
It represents physical quantities in the form of
It has no state
It has low memory
It is difficult to use
It is used in engineering and science
However, although analogue computers are
quite rare they do perform certain functions
better than digital computers (e.g. controlling
manufacturing processes in a factory; certain
type of modelling).
Position of compass dial
Room light dimmer switch
Speed of the car
It provides us discrete values
It represent physical values with help of
symbols or numbers
It has two states ON and OFF
It has big memory
These are easy to use
It is used in all field of life
Traffic light sequence
Analog to Digital conversion
and vice versa
In chemical factories ,the processes used to
make chemicals are usually controlled with
the help of computers. The signals from a
temperature sensor is a continually changing
analog to Digital (ADC) .
The computer then control the process by
outputting the digital-analog converter(DAC)
A modem is another example
In modem it is used to convert the binary
digits from a digital computer into an analog
signal that may be passed along telephone
Wires convert the analogue signal back into a
digital one that the computer is able to
The sound cards listens to the sound and
takes a measurement of the height of the
signal many times a second. The
measurement called sound sampling.
The sampling rate is the number of times the
sample is measured per second called it is
The higher the sampling rate the better the