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GLOAD

This command allows a previously saved picture to be recalled.

FILL

This command colours in an outlined shape.

CURSOR

This command returns the current cursor co-ordinates.

CHECK

This returns the colour of a specified pixel.

DASH

This allows the user to specify that lines and shapes are to be drawn using dotted or dashed lines.

The preceding commands are mainly concerned with the way in which pictures will be draw. The commands which follow specify the actual drawing operations.

PLOT

This command sets the colour of a specified pixel. The position of the pixel can be expressed in absolute terms, or relative to the current position of the cursor.

LINE

This command draws a line on the display. The positions of the start and end points can be absolute or relative to the current cursor position, and lines can also be specified in terms of their length and direction.

The shapes produced can also be scaled, rotated and sheared, Shearing refers to an angular displacement of parts of the shape, so that, for example, a square becomes a diamond, or capital letters become italics.

TRI

This command is used to draw triangles, and can cope with all types of triangle.

RECT

This command is used to draw rectangles. Like other commands it provides for displacement, scaling, shear rotation and colouring.

POLY

This command draws polygons, ranging from triangles through to circles. Many parameters can be specified, such as drawing the radii or chords of circles. The command can also be used in drawing curves.

MAT

This is a special command which allows the user to define a shape and then move, colour, scale, rotate, shear etc it – a macro facility. There is no limit to the complexity of shape defined in a macro – other than the memory capacity of the computer!