Examples

All examples are written for the Script Box. For CC: Tweaked add local engine = peripheral.find("billboard_engine") at the top (and see the note at Picture slide show).

Clock

Real time of the server, standing still at the left edge. show() does not redraw the same text, so calling it every second costs nothing.

engine.claim()
while true do
  engine.show(os.date("%H:%M"))
  sleep(1)
end

Minecraft time instead: engine.show(textutils.formatTime(os.time(), true)).

Changing messages

local MESSAGES = { "WELCOME", "SHOP OPEN 9-17", "SALE: DIAMONDS" }

engine.claim()
engine.setPixel("minecraft:gold_block")
engine.setSpeed(6)
while true do
  for _, text in ipairs(MESSAGES) do
    engine.setText(text)
    engine.runOff()                                  -- comes in from the right, crosses once
    while engine.isRunningOff() do sleep(0.5) end
  end
end

Right-aligned number

go(column) starts the text at a wall column. A text is (6 * #text - 1) * size columns wide.

engine.claim()
engine.setSpeed(1)          -- slow, so the text does not move a column between go() and stop()
local width = engine.getWallSize()
local function right(text)
  engine.setText(text)
  engine.go(math.max(0, width - (6 * #text - 1) * engine.getSize()))
  engine.stop()
end
for n = 10, 0, -1 do
  right(tostring(n))
  sleep(1)
end

Picture slide show

Drop the program and the images onto the box.

local SLIDES = { "mona.png", "blocks.png" }
local SECONDS = 10

engine.claim()
while true do
  for _, name in ipairs(SLIDES) do
    print(name, engine.drawImage(name, { fit = "fit" }))
    sleep(SECONDS)
  end
end

On CC, drawImage takes the bytes of the file instead of its name: local f = fs.open(name, "rb") local data = f.readAll() f.close() engine.drawImage(data).

A moving pixel

The middle dot · is exactly one pixel. With a redstone block as pixel it walks along the wall and powers what sits behind each column on its way; see Redstone punch card.

engine.claim()
engine.setPixel("minecraft:redstone_block")
engine.setSize(1)
engine.setSpeed(4)
engine.setText("\183")       -- the middle dot
engine.runOff()
while engine.isRunningOff() do sleep(0.2) end

Countdown launch show

A countdown from 10 at the right end of the wall in gold. The 0 runs off, then a single redstone block walks to the left end of the wall and sets off a contraption there: a lamp, a repeater line, a door, a minecart, fireworks. One engine does it all.

local START, SIZE = 10, 1
local width = engine.getWallSize()
if not width then error("The engine has no wall marked (wand missing?)", 0) end
local function rightColumn(text) return math.max(0, width - (6 * #text - 1) * SIZE) end

engine.claim()
engine.setPixel("minecraft:gold_block")
engine.setSize(SIZE)
engine.setSpeed(1)
for n = START, 0, -1 do
  engine.setText(tostring(n))
  engine.go(rightColumn(tostring(n)))
  engine.stop()
  sleep(1)
end

engine.setSpeed(8)                               -- the 0 walks off to the left
engine.runOff()
while engine.isRunningOff() do sleep(0.2) end

engine.setPixel("minecraft:redstone_block")      -- one dot carries the signal to the left end
engine.setText("\183")
engine.setSpeed(4)
engine.runOff()
while engine.isRunningOff() do sleep(0.2) end
print("Launched.")

Behind the left end of the wall, at the height of the text's middle row, a redstone lamp or comparator picks up the passing dot. Build your contraption from there.