OPTION EXPLICIT ON
OPTION DEFAULT NONE

MODE 3,8
DIM gridSize As Integer  = 5
DIM lineWeight As Integer = 1
DIM lineColour As Integer = RGB(150,150,150)

DIM boxLeft As Integer = 10
DIM boxTop As Integer = 10
DIM boxCols As Integer  = 5
DIM boxRows As Integer  = 5
DIM boxWidth As Integer = (gridSize+lineWeight)*boxCols + lineWeight
DIM boxHeight As Integer = (gridSize+lineWeight)*boxRows + lineWeight
DIM boxLineWeight As Integer = 1
DIM boxLineColour As Integer = lineColour


DIM x As Integer = 0
DIM y As Integer = 0

PAGE WRITE 2
CLS
BOX boxLeft, boxTop, boxWidth, boxHeight, boxLineWeight, boxLineColour

IF lineWeight > 0 AND gridSize > 0 THEN
 DO
   LINE boxLeft+(x*(gridSize+lineWeight)),boxTop,boxLeft+(x*(gridSize+lineWeight)),boxTop+boxHeight-lineWeight, lineWeight, lineColour
   x=x+1
 LOOP UNTIL x > boxCols
 
 DO
   LINE boxLeft, boxTop+(y*(gridSize+lineWeight)), boxLeft+boxWidth-lineWeight, boxTop+(y*(gridSize+lineWeight)), lineWeight, lineColour
   y=y+1
 LOOP UNTIL y > boxRows
END IF
PAGE WRITE 0
BLIT boxLeft,boxTop,boxLeft,boxTop,boxWidth,boxHeight,2

'Colour the centre marker of each grid square
DIM cursorX As Integer = boxLeft+lineWeight
DIM cursorY As Integer = boxTop+lineWeight

FOR y=0 to boxRows-1
 FOR x=0 to boxCols-1
 
   PIXEL cursorX+(x*(gridSize+lineWeight))+(gridSize\2),cursorY+(y*(gridSize+lineWeight))+(gridSize\2),RGB(255,0,255)
 
 NEXT x
NEXT y

DO
LOOP UNTIL INKEY$<>""

   PIXEL cursorX+(x*(gridSize+lineWeight))+(5\2),cursorY+(y*(gridSize+lineWeight))+(gridSize\2),RGB(255,0,255)

PIXEL cursorX+(x*(gridSize+lineWeight))+(5\2),cursorY+(y*(gridSize+lineWeight))+(gridSize\2),RGB(255,0,255)