User:Munin295/Memory circuit

A memory circuit is a redstone circuit which "remembers" its output state until told to change it.


 * T Flip-Flop
 * One input: toggle output state between off and on.
 * A t flip-flop answers the question: "How do I turn a button into a lever?"


 * SR Latch
 * Two inputs: set output on, reset output back off.


 * SRT Latch
 * Three inputs: set output on, reset output back off, and toggle output between off and on.


 * D Flip-Flop
 * Two inputs, a data input and a clock input, and only changes its output to match its data input when the clock input triggers it.


 * JK Latch
 * Two inputs: set output on, and reset output off, but toggle output if both inputs turn on simultaneously.

T Flip-Flop
A T Flip-Flop has one input and one output, and toggles its output between off and on when triggered by its input.


 * Lever
 * A lever can act as a simple T Flip-Flop. Its input is player activation, and it remembers its output state until told to change it.


 * Dropper-Loop T Flip-Flop


 * 1x2x2 (4 block volume), 1-wide
 * circuit delay: 3 ticks
 * When the item is in the bottom dropper, turning on the input pushes the item into the top dropper, turning the output comparator on. When the item is in the top dropper, turning on the input causes the top dropper to eject the item, but the hopper immediately sucks it in and returns it to the bottom dropper, turning the output comparator off.
 * Even though the item is being ejected, it is not possible to (accidentally or purposefully) pick it up before the hopper sucks it in. When an item is ejected into the Minecraft world as an entity (either by the player, mob death, a dropper, etc.), there is a short period of time in which it cannot be picked up, and hoppers suck items in before this period ends. So it is safe to stand around or on the circuit without interfering with it.
 * Because the output comes from a comparator used as an inventory counter, the output power level will only be 1 (with a stackable item) or 3 (with a non-stackable item).
 * Variations: The comparator can be moved to another side of the droppers. This can allow you to place a repeater on the hopper facing the dropper to activate it. Combined with the original version, this makes the circuit 1-wide alternating tileable.


 * {| class="collapsible wikitable"

! Schematic Gallery: Dropper-Loop TFFs


 * }


 * Dropped-Block T Flip-Flop
 * ''features vary (see schematics)
 * A dropped-block T flip-flop uses a 1-tick pulse to cause a sticky piston to push a block and not pull it back (called "dropping the block"), or retract a dropped block.


 * {| class="collapsible wikitable"

! Schematic Gallery: Dropper-Loop TFFs


 * }


 * Opposed-Piston T Flip-Flop


 * 1x4x3, 1-wide
 * circuit delay: 2 ticks (rising output) or 1 tick (falling output)


 * Locked-Hopper T Flip-Flop
 * features vary (see schematics)
 * A locked hopper TFF consists of an inverted rising edge detector keeping two hoppers deactivated until the input's rising edge. When the input turns on, the hoppers are activated just long enough for the item inside to move once, toggling the output.


 * {| class="collapsible wikitable"

! Schematic Gallery: Locked-Hopper TFFs

In both designs, the left hopper contains a single item.
 * }


 * Locked-Repeater T Flip-Flop


 * 2x5x2 (20 block volume), flat, silent
 * circuit delay: 3 ticks


 * Locked-Clock T Flip-Flop


 * 3x5x2 (30 block volume), flat, silent
 * circuit delay: 4 ticks