You may press one or several keys at a time, from either one or both envelopes.

You may replace any of the preset envelopes with one of your own by pressing

followed by the number of the envelope you wish to redefine.

PATTERN EDITOR allows you to design your own colour patterns in any of

the graphics modes.

When it starts you will be asked which mode you wish to use. Choose which you

would like to use and type the number, the possibilities are:

Mode 0 (128) 2 colours, 640 by 256 pixels

Mode 1 (129) 4 colours, 320 by 256 pixels

Mode 2 (130) 16 colours, 160 by 256 pixels

Mode 4 (132) 2 colours, 320 by 256 pixels

Mode 5 (133) 4 colours, 160 by 256 pixels

The other modes are unsuitable because they do not allow the display of

graphics.

Once the mode has been selected, a grid will be shown on the screen, with a

flashing cross in the top left-hand box; the cross can be moved around using the

cursor control keys-

The range of colours you can use to fill each box in the grid is given at the

bottom of the screen and to fill the box currently marked with a cross, simply

press the corresponding number. Each time you fill a box the large rectangle at

the top of the screen will be filled with the current pattern from the grid. The

eight parameters required to specify the current pattern are always displayed

at the side of the grid. Note, however, that the parameters are shown in

hexadecimal notation (i.e. the values are preceded with &).

Having produced a satisfactory pattern you can note down these numbers and

use them in your own programs to fill any of the solid shapes (such as triangles,

circles or ellipses) which the computer can plot.

Down the right hand side of the screen you will see a strip of coloured blocks.

This is the palette -- it allows you to change the relationship between the colour

numbers and the actual colour which is seen. To alter it type P.

The pointer by the palette will then start flashing and can be moved up and

down the strip using arrow up and arrow down. To change the appearance of a colour numberpress one of the keys 0,1,2,3,4,5,6,7 ,8,9,A,B,C,D,E or F; this will select the

actual colour from the 16 which are available. To return to the grid press

B 13