Graphics Utility

Graphic Aid


East Horsley, Surrey.





This is a machine-code routine to overcome an annoying


feature of Sinclair Basic: the CLS command must follow a


global PAPER, INK, FLASH or BRIGHT command or statement.


This means that if you have created a screenful of high-


resolution graphics and you want to make the whole screen


flash or change the ink or paper colour over the whole


screen, you have to execute a global colour statement then


clear your display and then redraw it.


This can be undesirable especially if your display took a


long time to draw. The machine-code routine can be called


during or after the program execution. The new attributes


for the screen are set using the RANDOMIZE N sequence where


N is chosen, according to page 116 of the manual. Then the


routine is executed by a call to 1+RAMTOP - this is 32570


on the 16K machine. [No, it isn't, but it doesn't matter;


the routine is relocatable - RLB]