Нарисовать прямоугольник, стороны которого состоят из разноцветных квадратиков - QBasic

  DEFINT A-Z
PRINT "Select screen mode"
PRINT
PRINT "    1    :  320 x 200 x 4 bit  [ EGA / VGA ]"
PRINT "    2    :  640 x 200 x 4 bit  [ EGA / VGA ]"
PRINT "    3    :  640 x 350 x 4 bit  [ EGA / VGA ]"
PRINT "    4    :  640 x 480 x 4 bit  [ VGA ]"
PRINT "    5    :  320 x 200 x 8 bit  [ VGA ]"
PRINT " Another :  Exit"
PRINT
  INPUT "Your choise [1-5] : ", Scrn
  cvt = 1
  SELECT CASE Scrn
    CASE 1: SCREEN 7: xr = 320: yr = 200: cv = 16
    CASE 2: SCREEN 8: xr = 640: yr = 200: cv = 16
    CASE 3: SCREEN 9: xr = 640: yr = 350: cv = 16
    CASE 4: SCREEN 12: xr = 640: yr = 480: cv = 16
    CASE 5: SCREEN 13: xr = 320: yr = 200: cv = 256: cvt = 32
    CASE ELSE: END
  END SELECT
  LOCATE 3, 5: PRINT "Resolution  X:"; STR$(xr); "  Y:"; STR$(yr)
  Kv = 10       ' Отношение разрешения к стороне квадрата
  kx = xr \ Kv  ' Кол-во квадратов по X
  ky = yr \ Kv  ' Кол-во квадратов по Y
  xs = xr \ kx  ' Сторона квадрата по X
  ys = yr \ ky  ' Сторона квадрата по Y
 
  FOR ix = 0 TO kx - 1
     cvt = cvt + 1
     LINE (ix * xs, 0)-(ix * xs + xs - 1, ys - 1), cvt MOD cv, BF
     LINE ((kx - ix - 1) * xs, yr)-((kx - ix - 1) * xs + xs - 1, yr - ys), (cvt + ky + kx - 2) MOD cv, BF
  NEXT
 
  FOR iy = 1 TO ky - 2
     cvt = cvt + 1
     LINE (0, (ky - iy - 1) * ys)-(xs - 1, (ky - iy - 1) * ys + ys - 1), (cvt + kx + ky - 2) MOD cv, BF
     LINE (xr - xs, iy * ys)-(xr, iy * ys + ys - 1), cvt MOD cv, BF
  NEXT
 
WHILE INKEY$ = "": WEND