PLOT

Syntax: PLOT x,y,colour     (Fast PLOT Toolkit)
   and: PLOT [#ch,] x1,y1   (DIY Toolkit)
Location: Fast PLOT/DRAW Toolkit and DIY Toolkit Vol G

These commands force a pixel to be set at the absolute screen position x,y.

On the Fast PLOT/DRAW Toolkit version, the origin (0,0) is the upper left corner of the full QL screen, the opposite corner(diagonally) is (511,255). Two neighbouring points do not have any space between them.

The DIY Toolkit version uses co-ordinates calculated by reference to the top left hand corner of the specified window (default #1).

Co-ordinates greater than 511 (x) or 255 (y) or smaller than 0 are modulated (eg. x MOD 511).

The base address of the screen used by the Fast PLOT toolkit version is defined with SCRBASE.

CROSS-REFERENCE:
DRAW draws a line, SCLR clears the screen, and REFRESH makes the screen defined by SCRBASE visible. 
Compare the other implementation of PLOT.
