FAQ

See also the official FAQ, and the github FAQ.

Common abbreviations

• 1bm: One Bit Memory. The component in the game capable of storing a single bit with a save signal.
• CC: Custom Component, one made in the Component Factory.
• CLA: Carry Look Ahead. A special way of building Byte adders that reduces delay.
• CS: Computer Science.
• DAG: Directed Acyclic Graph. A special kind of graph, used in the game for simulation. This is the reason why cyclic dependencies aren't possible without Delay Lines.
• DB: Delayed Buffer. An obsolete term for the Delay Line component in the game that outputs the value that was input in the tick before.
• FA: Full Adder. The level/component in the game that adds 3 bits to a 2 bit result.
• LFSR: Linear Feedback Shift Register. A NAND efficient alternative to Counters.
• LUT: Look Up Table. A common pattern for good solutions for combinatorical levels.

How do I Rotate?

• You can rotate a component before it is placed with the hotkey, which by default is Space.

• A single placed component can be rotated the same way provided it is not connected to anything else.

• A group of connected components and wire can be rotated by selecting, cutting, rotating and then pasting it. By default this is
  • Shift-drag, CTRLX, Space, CTRLV
  • Any wire connection internal to the selection will be preserved.
  • However this will break any wire connections (and watch links) between the selection and the rest of the circuit. You cannot rotate a selection without disconnecting it from the rest of the circuit.

I've finished the last level but my profile says "Complete: 95%"

Some levels have not syncronised with the server for some reason. To resubmit them go to the game Options → Score Sync. This will show Resubmit for the levels that the game is resubmitting. This fixes this issue most of the time.

TODO: Other options to try if this doesn't resolve it.

What are the extra RAM input/outpus for?

They allow the RAM to load and store words wider than 64 bits on 64 bit wires.

RAM, Latency RAM and Fast RAM have 4 Input value and Output pins. Only the first is used when the data width is set to 8, 16, 32 or 64 bits. The first 2 are used when the data width is set to 128. All 4 are used when it is set to 256.