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How do signals work?
A signal is a number from 0 to 255, carried by a thin signal cable, an optical fibre or by radio. It counts as on from 128. Logic parts answer 255 or 0, and each part adds one turn of 50 ms (cables, junctions and repeaters add none), so you can watch a signal travel through a build. Signals and power are two different things: the signal cable carries only information, while lamps and motors need a power cable (power). Logic parts need no power cable: the signal cable that feeds them is enough. An unplugged input reads 0.
What does each logic part do?
| Part | What it does |
|---|---|
| Delay | Gives back what it received N turns ago: 0.05 s to 30 s (0.5 s by default). |
| Logic gate | AND, OR or NOT, bit by bit on the 8 bits. NOT gives 255 minus A. |
| Op-amp | A + B (capped at 255), A - B (floor 0), A x B / C (C unplugged = 255, a percentage), A > B, A = B. |
| Memory | On the rising edge of its Write input, copies its Value input and keeps it (starts at 0). |
| Optical coupler | 8 command channels on one side, a fibre on the other. As a laser it sends, as a photocell it reads. 5 W on a small power cable. |
| Display panel | A wall plaque with 4 inputs; {1} to {4} in its text show the live values. 1 W on a small power cable. |
| Light switch, button | The switch sends a value you choose (0 to 255, 255 by default); the button stays pressed for 1 second. |
The mode of each part (gate type, delay, op-amp operation) is set on its sheet and engraved on its model, so you can read a circuit by looking at it. Each part is crafted: the coupler wants a lens, the gate silicon and gold contacts.
How do I make a machine react to the world?
- Presence sensor: puts 255 on its signal cable while a player or creature stands in front of it, within 1 to 8 m (4 by default), and holds it 3 s by default after the last one left. 3 W on a small power cable.
- Level sensor: set against a tank, it gives the tank's fill from 0 to 255. 3 W.
- Chunk sensor: 255 while the land around it is loaded and settled. 5 W.
- Relay and dimmer: an electric relay closes its power line when the command is 128 or more (2 W). A transistor passes signal / 255 of the current, so lamps shine in quarters. Doors and trapdoors open at 128 and fall shut below.
- Metres: tachometer (shaft speed), voltmeter, ammeter and torque metre turn a reading into a 0-255 signal, scaled by a range you set on the sheet.
- Signal writer: a chart recorder. 15 W and paper required; it draws the signal (8 coloured pens from an octo fibre), 128 points a sheet, and keeps up to 16 finished sheets.
How do I build a clock or a counter?
- 1
A clock
Loop a delay into a NOT gate and back into the delay: the output flips every delay time.
- 2
A pulse
A button into a memory's Write input stores a value at the click.
- 3
A counter
Button to Write, memory to op-amp (A + 1) and back to Value. Every click adds one.
- 4
A threshold
A switch set to a value and an op-amp in A > B mode: on when the reading passes it.
- 5
A battery gauge
The battery's charge signal times 100, divided by 255 (op-amp A x B / C), on a display panel.
How does radio work?
- 256 channels, an amplitude of one byte. An emitter sends its signal-cable value; a receiver puts the amplitude it hears on its signal cable. The strongest emitter on a channel is the one a receiver hears.
- Omnidirectional antenna (a mast) or dish (a 2 degree cone, aimed by hand or following the Earth or the Moon). Radio never goes through the ground: a dish under the horizon of the body it follows stays silent.
- Pick a target on the sheet: Nearby (100 m), Village (1 km), Region (10 km), Far (100 km), the Moon or the Earth. It tells you in big letters what it will consume. An omni emitter takes up to 2 kW, a dish up to 100 kW.
- Fibres carry signals up to 10 km: mono (1 byte) or octo (8 channels, one colour each). A signal cable reaches 256 m; place a repeater to go farther.
Questions
Why is my signal late?
Every logic part adds one turn of 50 ms. A chain of ten parts delays the signal by half a second; cables and junctions add nothing.
Do logic parts need power?
No. The signal cable that connects them feeds them. Only the optical coupler (5 W) and the display panel (1 W) want a small power cable.
How do I make a lamp turn on when I come near?
Put a presence sensor on a small power cable, run its command output to an electric relay on the lamp's power line, and the lamp lights while you stand in front of it.
Can I build a computer?
The parts are enough for registers, counters and an arithmetic unit; players build processors for the art of it.
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