Tutorial:Soft inversion

Soft inversion is a mechanic of pistons and sticky pistons that creates a inverter (NOT gate). When a piston is activated even by a weak (soft) power source it turns off any redstone torch attached to its block within a single Bedrock redstone tick (the piston activates on a C-tick and the torch turns off on a P-tick). This NOT gate behavior is the foundational building block for more complex circuitry, all other compact logic circuit designs are built from this core property of soft inversion. The mechanic works even if the piston is blocked and cannot extend.

The key distinction of Soft Inversion lies in the way a piston processes weak (soft) power compared to other opaque blocks.

In Bedrock Edition, a block is considered weakly powered (soft powered) when:

• Redstone dust runs past it, but is not configured to point directly into it.
• Redstone dust is placed directly above it.
• It is adjacent to a strongly-powered block.

For most opaque blocks (e.g., Stone, Wool):

• A block receiving soft power will not turn off an attached redstone torch. A strong power source (e.g., a redstone repeater or redstone comparator facing the block) is required to turn off the attached torch.

For pistons (the soft inversion mechanism):

• A piston receiving soft power will turn off an attached redstone torch.

The primary advantage of soft inversion is its excellent tileability. Because the core mechanism often relies on vertical power transmission through blocks, multiple inverter units can be placed directly adjacent to each other (stacked vertically or side-by-side) without causing cross-talk. This allows for the construction of dense, modular logic arrays, such as for AND gate banks or memory cells, in a footprint that is impossible with traditional 1-wide, tileable torch inverters.

The core sorting mechanism is controlled by a soft inverter (piston + redstone torch). When the hopper is over 41 items (represented as diamonds in the schematic) the comparator activates the piston and turning off the torch, which locks the hopper. This sorter is optimized for bedrock redstone tick speeds, making it faster than using a java design on bedrock.

• Rapid Clocks and Pulse Limiters: Soft inverters can be integrated into clock circuits to create extremely rapid, stable pulsers without the risk of torch burnout associated with 1-tick torches.
• Logic Paths: They enable the creation of complex logic (like XOR or XNOR) where the final output is dependent on an inverted signal.
• Compact Memory Cells: The tileable nature allows for the design of very dense memory circuits, such as shift registers or ROM arrays.
• Implicit Latching: Some soft inverter configurations have inherent latching properties, where the output state persists briefly after the input changes, useful for filtering short pulses.

The piston + redstone torch combination serves as a fast and compact NOT gate (inverter), taking power from adjacent dust and outputting an inverted signal.

The one-wide tileable AND gate is constructed using soft inversion mechanics. It requires two inputs, each connected to a solid block with an attached redstone torch. These torches serve as inverted inputs. The two inverted signals (the torches) are positioned to soft-power a single central piston. An obsidian block is placed on the piston face. The gate functions as an AND gate because the piston is only unpowered (and the output torch is thus powered) when both inputs are ON, which simultaneously turns both input torches OFF. If either input is OFF, its corresponding torch is ON, soft-powering the piston and keeping the output OFF.

The one-wide tileable NAND gate is built by taking the output of the AND gate and inverting it with a final redstone torch. The initial structure is identical to the AND gate. Two inputs feed into two inverting redstone torches, which soft-power a central piston. An obsidian block is placed on the piston face. By attaching a final redstone torch to the output side of this obsidian block, the signal is inverted. The NAND gate outputs ON whenever at least one input is OFF, and outputs OFF only when both inputs are ON. This makes it the inverse of the AND gate.

Soft Inversion allows for the creation of extremely compact, one-wide, tileable, and silent RS NOR Latches (1-bit memory cells). These latches are immune to the noise and signal strength issues of standard dropper-based latches.

• This design requires an input pulse of at least 2 game ticks to prevent the circuit from entering a clocking state.
• The use of pistons (as transparent blocks) in the structure enables a simple, interference-free global reset line to be wired across the top of multiple latches.

Soft Inversion is the foundation for creating the fastest possible one-tick pulse limiters and one-tick clocks in Bedrock.

• One-Tick Pulse Limiter: A piston/torch inverter is looped back to power itself, creating a momentary pulse (1 game tick) before the circuit snaps back to its stable state. This is highly compact, silent, and one-wide tileable.

• One-Tick Clock: Two piston/torch inverters are connected in a loop, creating a self-sustaining oscillation that toggles every game tick (a 2-tick cycle). This is the fastest, silent, and one-wide tileable clock .

A fundamental soft inverter design involves:

1. A (sticky) piston facing upwards or sideways.
2. A redstone block or other conductive block in front of the piston.
3. A control line that directly powers the piston to make it retract.
4. An indirect power source (e.g., redstone dust on a block above the piston) that would cause the piston to extend if it were directly powered.

When the control line is OFF, the indirect power extends the piston, pushing the redstone block to power the output. When the control line is ON, the piston is directly powered and retracts. If the timing is arranged so the indirect power is removed in the same tick, the piston retracts without ever extending, leaving the output OFF.

• Redstone circuits/Logic - For standard logic gate implementations.
• Redstone components - Details on component behaviors.
• Tutorial:Redstone - General redstone guides.