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]