AMSTRAD CPC464 User Manual page 43

PLOT
Unlike the locate command, plot is used to determine the position of the graphics cursor, using pixel
co-ordinates. (A pixel is an extremely small segment of the screen).
Note that the graphics cursor is not visible and is different to the character cursor.
There are 640 horizontal pixels by 400 vertical pixels. The x,y co-ordinates are positioned with
respect to the bottom left corner of the screen, which has x,y co-ordinates of 0,0. Unlike the locate
command use-d for characters, the co-ordinates do not differ in modes 0,l, or 2.
To see this, first reset the computer using [CTRL] [SHIFT] [ESC], then type in (remembering to
[ENTER]) :
p l o t 3 2 0 , 2 0 0
A small dot will appear in the centre of the screen.
Now change the mode by typing:
mode 0
p l o t 3 2 0 , 2 0 0
You will see the dot is still in the centre but is now larger. Change the mode again and type in the
same command to see the effect in mode 2. Type in:
mode 2
p l o t 3 2 0 , 2 0 0
The dot is still in the centre, but it is now much smaller.
Plot several dots over the screen in various modes, in order to accustom yourself with this command.
When you have finished, return to mode 1 and clear the screen by typing in:
mode 1
DRAW
First reset the computer using [CTRL][SHIFT] and [ESC]. The draw command draws a line from the
current graphics cursor position. To see this in more detail, draw a rectangle on the screen by using
the following program. We start by repositioning the graphics cursor with a plot command. Then
drawing a line from the graphics cursor position, up towards the top left corner, then from here to
the right corner etc.