User guide

e.g. *PO. 80
This command is used to specify which icons are to be used as the pointer: Each
pointer consists of two parts. The first icon, i1, is used as the black part of the pointer. The
second icon, i2, is used inverted to draw the white mask for the pointer: If icon i2 is not
specified then it is assumed that icon number i1+1 is to be used: This method is used to
ensure that if the pointer moves over a black area it does not disappear, but a white border
can be seen.
If an icon is to be used which has not got a mask then you can either use itself (e:g:
*POINTER 80,80) or use icon 95 as the mask (e:g: *POINTER 80,95) which is full white
square. If the icon itself: or a blank mask are used, the icon will disappear on black areas: It
is therefore recommended that icon 95 is used as the mask when no special mask is
available. Try modifying line 100 of the following program to use masks of 80 and 95 to see
the effect.
10 MODE 4
20 *DESK
30 *MCURSOR OFF
40 *BUTTONS 0
50 *WINDOW 5,20,20,5
60 MOVE 0,0
70 MOVE 639,0
80 PLOT 85,0,511
90 PLOT 85,639,511
100 *POINTER 80
110 *SHOWPOINTER
120 REPEAT
130 *MOVEPOINTER
140 UNTIL FALSE
e.g. *PO. ON
Whenever the pointer is to be used a *POINTER ON command MUST be used first.
This command reserves 256 bytes of memory as workspace. This workspace is only
claimed when the BREAK key is pressed, or a *BREAK command is used. (Note: when a
second processor is used this memory is always available, but it doesn't affect PAGE).
If the pointer is not being used, and the extra 256 bytes are required then a
*POINTER OFF command, followed by *BREAK will allow the memory to be used.