Computercraft Multi-purpose Ticker Sign V2

-- Auto detects monitor
tSides = {"left","right","bottom","top","front","back"}

for i = 1, #tSides do
  monitor = peripheral.wrap(tSides[i])
  if monitor then
        side = tSides[i]
        break
  end
end

mon = peripheral.wrap(side)

-- number of signs
signs = 3
--color variable
c = 0

-- Randomizes text color
function raincol()
    c = math.random(1,15)

    --Converts the random number into a valid color value
    if c == 3 then
        c = 4
    elseif c == 4 then
        c = 8
    elseif c == 5 then
        c = 16
    elseif c == 6 then
        c = 32
    elseif c == 7 then
        c = 64
    elseif c == 8 then
        c = 128
    elseif c == 9 then
        c = 256
    elseif c == 10 then
        c = 512
    elseif c == 11 then
        c = 1024
    elseif c == 12 then
        c = 2048
    elseif c == 13 then
        c = 4096
    elseif c == 14 then
        c = 8192
    elseif c == 15 then
        c = 16384
    end
    mon.setTextColor(c)
end

-- Beginning position of scrolling text
local pos = 18
pos2 = 24

-- Initial Setup

mon.clear()
raincol()
mon.setTextScale(5)
sign = 1

-- Main Program
while true do
    -- Sign Toggle and reset
    if pos == -pos2 then
        pos = 18
        raincol()
        if sign == signs then
            sign = 1
        else
            sign = sign + 1
        end
    end

    --clears monitor and adjusts cursor position
    mon.clear()
    mon.setCursorPos(pos,1)

    --Displays Signs
    if sign == 1 then
        mon.setTextColor(colors.orange)
        pos2 = 24
        mon.write("Welcome to Rolcam's Shop")
    elseif sign == 2 then
        pos2 = 50
        mon.write("Eat at Crazy Betty's Canned Bread Emporium!!!")
    elseif sign == 3 then
        raincol()
        pos2 = 15
        mon.write("Your Ad Here")
    end

    --Adjusts Cursor position variable
    pos = pos - 1

    --Prevents overflow errors (Keep this)
    os.sleep(0.1)

end