Billboard Engine

Install: put billboard-1.1.0.jar into the mods folder, together with Fabric API. Needs Fabric Loader 0.19.5 or newer and Java 25. CC: Tweaked is optional. Worlds from 1.0.x load as before.

Script Box (new block)

• Runs one Lua program that drives the engine it touches, no other mod needed. Recipe: the engine recipe with paper instead of the glass pane.
• Drag the .lua file and up to 8 images from your file manager onto its screen. The screen lists the files (with a button to remove each), shows the last output lines and has Restart and Stop. Only the placer and operators may change a box. In single player a Folder button opens the box's folder, and a click on a file opens it in your editor.
• Files live in <world>/billboard/scripts/<id>/; the program starts with the world and runs while its chunk is loaded. Breaking the box drops it blank and deletes its files.
• The engine table has the same functions as the ComputerCraft peripheral (drawImage takes an image name), plus sleep, print, os.time (Minecraft time), os.date (real time), os.clock, os.epoch, os.day and textutils.formatTime.
• Texture: a cardboard box with a paper label of code lines and a small light: dark when stopped, flickering green while the program runs, red after an error.
• /billboard script <pos> restart|stop|status. New settings in config/billboard.properties (time per tick, limits, operators only, switch off). Lua VM: Cobalt (MIT), packed into the mod.

Engine

• Letter size 1 to 9: every dot of the 5x7 font becomes n x n blocks, up to 45 x 63 blocks per letter. Set it with Size - / + in the engine screen. A size change redraws a running or stopped text at once.
• The pixel slot is now a sample slot: clicking it with a block copies the block, you keep it. Blocks can also be dragged there from JEI or REI. Breaking the engine drops only the wand. Engines from older versions hand their real pixel blocks back (they pop out on top of the engine).
• The engine must now touch its wall: place it directly behind one wall block, full face contact. It no longer works from up to 16 blocks away, and it refuses a wand marked for a different wall or without both corners. An engine that already shows text keeps running; the rule applies at its next start.
• The engine ignores redstone power from the side that touches the wall, so a redstone block pixel can't start it.
• Engine screen messages also go to the chat; a message too long for the status line ends in "...".
• New character · (middle dot): a single dot in the middle row. From Lua write it as "\183".
• Bigger walls: up to 256 wide and 384 high (the whole world height) by default, up to 512 wide with config/billboard.properties.
• The engine screen greys out text, speed, size and Go while a program holds the engine.

Lua control (Script Box and ComputerCraft)

• Pictures and animations: drawImage(data) shows a PNG, JPEG, GIF or BMP on the wall, every pixel as the block with the nearest color (about 260 vanilla blocks, all free). Animated GIFs play by themselves. drawPixels draws pixels made by a Lua program; isPainting, isShowingPicture, play. Big pictures are placed over several ticks (blocks_per_tick), so the server doesn't freeze.
• show(text): sets the text and shows it standing still at the left edge (setText, go and stop in one). The same text again is not redrawn, so a clock can simply call it every second.
• runOff(): the text scrolls through once and the wall is restored afterwards (also /billboard runoff).
• setSize(n) / getSize(), setPixel("minecraft:gold_block") / getPixel().
• go(column) starts the text at a wall column, e.g. right-aligned with go(width - textWidth); getWallSize() returns the width and height of the marked or shown wall.
• claim(), release(), isClaimed(): a claimed engine takes changes only from its holder and ignores sign and redstone; its screen keeps Stop and Restore as an emergency brake.

Other

• Authors are shown as Claude and Konitor.