#include "crt.bi"

screenres 640,480,8

dim as double dStart = timer
dim as long iScale = 32

do

  dim as string sGrid = "BH50"
  for Y as long = 0 to 99
    randomize ((Y\2)+33)*timer
    dim as long iR
    for X as long = 0 to 99
      if (X and 1)=0 then iR = cint(rnd)
      if ((X+Y+iR) and 1) then if iR then sGrid += "BDE" else sGrid += "FBU" else sGrid += "BR"
    next X
    sGrid += "BL100BD"
  next Y

  draw "S" & iScale
  do
    screenlock : cls
    draw "bm320,240TA" & cint(fmod((timer-dStart)*18,360))
    draw sGrid ': draw "bm321,240" : draw sGrid
    screenunlock : sleep 5,1
    do
      var sKey = inkey : if len(sKey)=0 then exit do
      dim as long iKey = sKey[0]: if sKey[0]=255 then iKey = -sKey[1]
      select case iKey
      case asc("+"),asc("="): if iScale < 256 then iScale += 1 : draw "S" & iScale
      case asc("-"),asc("_"): if iScale > 2 then iScale -= 1 : draw "S" & iScale
      case 13 : exit do,do
      case 27 : exit do,do,do
      end select
    loop
  loop
loop