[MCPE-11906] Redstone Torches hold a steady signal instead of creating a burnout clock Created: 30/Nov/15  Updated: 21/Aug/17  Resolved: 21/Aug/17

Status: Resolved
Project: Minecraft (Bedrock codebase)
Component/s: None
Affects Version/s: 0.13.0
Fix Version/s: None

Type: Bug
Reporter: Cameron Young
Resolution: Cannot Reproduce Votes: 0
Labels: redstone

Attachments: PNG File Bluesideon.png     PNG File RedSideOn.png     PNG File torch-taking-1-tick-to-turn-on.png    
Issue Links:
Relates
relates to MCPE-12776 Dropper or dispenser is not activated... Resolved
Confirmation Status: Unconfirmed
Platform: Windows

 Description   

A redstone torch burnout clock seems to not work quite well: the torches themselves pulse, but the connecting redstone wire does not

To reproduce: Place two solid blocks next to each other on the ground. Place four torches, on opposite sides of the blocks. Put one solid block on top of each torch, and run a redstone line atop the two original blocks.

What I expected: Random and sporadic pulsing of the torches and a one tick pulsing of the redstone line above the torches

What happened: The redstone line stayed solidly powered through the cycles of the clock, causing this to not qualify as a one tick clock.

Description of the screenshots: In RedSideOn, the torches of the red side are both on, and in Bluesideon, the blue side torches are on, and in both the redstone lamp is powered. These two screenshots represent the only two states that the clock goes through in a cycle, where in neither state is the upper redstone (represented by the lamp) un-powered.

Add a comment with any issues regarding this. The closest I could find to this was MCPE-11547, but I feel that the other report is not quite about this.



 Comments   
Comment by [Mojang] Mega_Spud (Jay Wells) [ 21/Aug/17 ]

This ticket has been resolved as 'Cannot Reproduce' as it has not been updated recently (1 year+)

Comment by AMAN4700 [ 02/Jun/16 ]

Does this bug still appear in 0.14.3? Please respond.

Comment by PHO [ 04/Dec/15 ]

I think it is possible that MCPE-11953 is the source of the glitch.

Comment by Cameron Young [ 02/Dec/15 ]

With the redstone lamp being used to show the states of the redstone wire, I found it to be inaccurate, as redstone lamps do not update within one tick. When replicating this with a door in place of the lamp (since doors are proven to detect very short pulses), I found that the door made no sound, did not interact differently, and did not visually change. This addresses a downfall of RedSIdeOn and BlueSideOn.

Comment by PHO [ 01/Dec/15 ]

In my last comment I suspected that torches had no delay to turn on. This was proven to be wrong in the general case by the circuit shown in torch-taking-1-tick-to-turn-on.png. It has a NOR gate where one of its input is directly connected to an activated lever and another is negated by a torch. When the lever is deactivated, there will be 1 tick of moment where both inputs being low if and only if the torch takes 1 tick to turn on, producing a 1 tick pulse from the NOR gate and thus initiates the clock connected to its output. The result was that the clock did get initiated so the turning-on delay was proven to be 1 tick, at least in this setup.

Comment by PHO [ 01/Dec/15 ]

Confirmed on 0.13.0 / iOS. At first I thought this was just another example of MCPE-11871 but soon realized I was wrong. In this setup, torches behave as if they had 1-tick delay for turning off but no delay for turning on. That is,

  1. Torches on the blue side are turned on. On the red side they are turned off. Due to the solid blocks above them powering the wire, the blocks on the ground are weakly powered at this point.
  2. 1 tick later, two torches on the blue side turn off. As soon as the wire gets unpowered, torches on the red side turn on and thus the wire gets powered again in the same tick.
  3. 1 tick later, torches on the red side turn off, and then blue side torches turn on instantaneously.

However, this is contrary to MCPE-11869, which shows that torches have no redstone delay for turning off (despite a visual delay being observable) (Correction: In my comment to MCPE-11869 I proved that torches have 1 tick delay for turning off). The reason for torches on sides being alternately turned on and off is unexplainable as well, because if my hypothesis above were correct, all of the 4 torches might stay turned on. This may have something to do with the 2nd bug reported in MCPE-11855 but I'm not really sure.

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