Matrix

codes = {}
function randGreen()
local a = math.random(1,2)
if a == 1 then
return colors.lime
elseif a == 2 then
return colors.green
end
end

function newCode()
local template = {
x = math.random(1,51),
size = math.random(1,4),
y = 0,
color = randGreen()
}
template.y = 1 - template.size
table.insert(codes,template)
end

function increment(one,two)
if one > two then
return -1
elseif one < two then
return 1
end
end

function drawLine(sX,sY,eX,eY,tColor,bColor)
paintutils.drawLine(sX,sY,eX,eY,bColor)
term.setCursorPos(sX,sY)
for i=sY,eY,increment(sY,eY) do
term.setCursorPos(sX,i)
term.setTextColor(tColor)
term.write(string.char(math.random(33,126)))
end
end

function redraw()
term.setBackgroundColor(colors.black)
term.clear()
for i,v in pairs(codes) do
v.y = v.y + 1
drawLine(v.x,v.y,v.x,v.y+v.size,colors.black,v.color)
if v.y > 19 then
table.remove(codes,i)
end
end
end

while true do
for i=1,3 do
newCode()
end
redraw()
sleep(0.1)
end