Logo is very
simple computer language for giving instructions to a computer. It is usually
used to draw shapes on the computer screen or to move a motorised buggy or
"turtle" around the floor, e.g.
REPEAT 4 [RIGHT 90 FORWARD 5]
(Just follow the commands by stepping forward 5 paces and turning right 90
degrees, then repeat this 4 times and you will end up moving in a square.)
**Most
GCSE exam papers include a question using or interpreting simple Logo commands**
HyperText Markup
Language (HTML) (not required for GCSE)
is a very different, but still quite simple, language for telling the computer
how to display text and pictures on the screen. It is used by all Internet
browsers to communicate with each other via the telephone line, e.g. the
following will put some bold text and a picture called Image1.gif on the screen:
<b>A picture of me</b> <img src="Image1.gif">
These instructions are saved with .htm or .html added to the end of the
filename.
Visual Basic (not required for GCSE)
is used to write many of the simpler programs you use on a computer. It is
written with a normal text editor using simple (but modified) English commands
then 'compiled' into binary number code (00101011) that is faster for the
computer to use. The compiled program is saved with .exe added to the end of the
filename.
Some application programs,
like MS Word, Excel and Access (themselves written using a more advanced
programming language) also include a simple Visual Basic editor.
This enables the more experienced user to write small programs,
called macros, to enhance the functions of these applications
even further. For example, the European accent toolbar we have in
this school for use in Word uses macros like this one:
Rem Cedilla
CharLeft 1, 1
c$ = Selection$]()
p = InStr("cCçÇ", c$)
If (p <> 0) Then
EditClear
Insert Mid("çÇcC", p, 1)
Else
CharRight 1, 1
End If
(This basically moves the
cursor and selects the last character typed. If it is the letter c it deletes it
and replaces it with a ç or vice versa.) Fortunately,
this is A'level material and only put here to wet your appetite.