local p = { 0,memory.readbyte(0x508),
        0, memory.readbyte(0x50b) }
local c = { 0, memory.readbyte(0x53b), 0, memory.readbyte(0x6b)}
local fail = 0
local lastpos = memory.readbyte(0x508)

local function Stuff()
p[1] = memory.readbyte(0x508)
p[3] = memory.readbyte(0x50b)
c[1] = memory.readbyte(0x53b)
c[3] = memory.readbyte(0x6b)

gui.text(120,115,string.format("Cam X: %3d (%3d)\nCam Y: %3d (%3d)\nX: %3d (%3d)\nY: %3d (%3d)",c[1],c[1]-c[2],c[3],c[3]-c[4],p[1],p[1]-p[2],p[3],p[3]-p[4]),"#ffffff","#00000060")

if (c[1] - c[2] == 0) then
    gui.box(10,10,150,150)
    fail = fail + 1
end

gui.text(10,10,string.format("Fails: %4d - Speed-o-meter: %3i",fail,memory.readbytesigned(0x4dc)))

p[2] = p[1] - p[2]
p[4] = p[3] - p[4]

c[2] = c[1] - c[2]
c[4] = c[3] - c[4]

p[2] = p[1]
p[4] = p[3]

c[2] = c[1]
c[4] = c[3]

end

emu.registerafter(Stuff)