Plot Numbers
------------

b0-b1: 00 move
       01 plot in current foreground colour
       10 plot in logical inverse colour
       11 plot in current background colour
b2   : 0  relative coords
       1  absolute coords

b6-b7=00 - draw line:
b3   : 0  last point not omitted
       1  last point omitted
b4   : 0  solid line
       1  dot-dash line
b5   : 0  first point not omitted
       1  first point omitted

b6-b7<>00:
40 Plot point
48 Fill to non-background
50 Fill triangle
58 Fill to background
60 Fill rectangle
68 Fill to foreground
70 Fill parallelogram
78 Fill to non-foreground

80 Flood to non-background
88 Flood to foreground
90 Circle outline
98 Circle fill
A0 Circle arc
A8 Circle segment
B0 Circle sector
B8 Block copy/move/swap:
    b0-b1: 00 no action
           01 copy
           10 move
           11 swap (copy and move)

C0 Ellipse outline
C8 Ellipse fill
D0 Font plot
D8
E0
E8 Sprite plot (BBFW: block swap)
F0
F8


CIRCLE x,y,r                      -> MOVE x,y:PLOT 145,t,0
CIRCLE FILL x,y,r                 -> MOVE x,y:PLOT 153,r,0
DRAW x,y                          -> PLOT 5,x,y
DRAW BY x,y                       -> PLOT 1,x,y
ELLIPSE x,y,a,b                   -> MOVE x,y:PLOT 0,a,0:PLOT 193,0,b
ELLIPSE FILL                      -> MOVE x,y:PLOT 0,a,0:PLOT 201,0,b
FILL x,y                          -> PLOT 133,x,y
FILL BY x,y                       -> PLOT 129,x,y
LINE x1,y1,x2,y2                  -> MOVE x1,y1:DRAW x2,y2
MOVE x,y                          -> PLOT 4,x,y
MOVE BY x,y                       -> PLOT 0,x,y
PLOT x,y                          -> PLOT 69,x,y
PLOT BY x,y                       -> PLOT 65,x,y

RECTANGLE x,y,w,h                 ->
RECTANGLE FILL x,y,w,h            -> 
RECTANGLE x1,y1,w,h TO x2,y2      ->
RECTANGLE FILL x1,y1,w,h TO x2,y2 ->
RECTANGLE SWAP x1,y1,w,h TO x2,y2 ->

CLS                               -> VDU 12
CLG                               -> VDU 16
COLOUR n                          -> VDU 17,n
GCOL n                            -> VDU 18,0,n
GCOL m,n                          -> VDU 18,m,n
COLOUR l,p                        -> VDU 19,l,p,0,0,0
COLOUR l,r,g,b                    -> VDU 19,l,16,r,g,b
MODE m                            -> VDU 22,m
PLOT k,x,y                        -> VDU 25,x;y;
ORIGIN x,y                        -> VDU 29,x;y;
TAB(x,y)                          -> VDU 31,x,y