[MC-11165] The upward facing piston monostable is both orientational and coordinate dependant

The upward facing piston monostable is very inconsistent.
I will show 4 situations, each with 2 inputs, 2 pistons as outputs, and 2 pictures of what happens when I flick the first or second lever.
Each of this has the lever above and on the left, and the pistons on the right and on the bottom. I will change the direction the pistons are facing, and move the setup for each situation.

In situation 1 (Picture 1 and 2), we see that powering the lever on top powers only the piston on the right, and powering the other lever powers the other piston.

In situation 2 (Picture 3 and 4), we see that powering the lever on top powers none of the 2 pistons, and powering the other lever powers the piston on the right.

situation 3 (Picture 5 and 6) is identical to situation 2, the 2 pistons are just facing a different direction, and are in a different location.

situation 4 (Picture 7 and 8) is identical to situation 1, one of the pistons is just facing a different direction, and are in a different location.

The top of the pictures is always facing f:2(North)
Also: I know this is a duplicate, but I just wanted to make the bug more clear 🙂

I really hate this bug, and I think it should be fixed by pre-release.

UPDATE:
Powering the monostable with redstone or repeater actually makes a difference.

EDIT: Since 14w19a, this monostable works consistently in one orientation, in the other however it is still coordinate dependant.

Nice 20w18a repro: https://www.youtube.com/watch?v=ptK-7n--yYM

Linked issues

is duplicated by 13

MC-11064 New T-Flip Flop nonfunctioning Resolved

MC-12518 directional quirk with redstone Resolved

MC-12552 Directional Bug (Piston) Resolved

MC-15583 Piston Monostables Resolved

MC-24009 Directional issue with Redstone Flip-Flop Resolved

8 more links

relates to 1

MC-182452 Pistons powered by redstone on slabs is incorrect Open

Attachments

2019-08-19 04-15-00_2.mp4

2024-08-20_23-17-03.mp4

Comments 16

Eric R 2013-09-09T15:19:33Z

Can confirm for 1.6.2.

DicoTheRedstoner 2014-05-12T21:53:33Z

This is now consistent in one orientation, in the other orientation it is still coordinate dependant.
(14w19a)

Torabi 2014-08-07T01:14:58Z

According to a comment on this video, this is caused by the order of the block updates:

This is a bug that has existed since pistons were added. To fix the t-flip-flop functionality after the mono-stable circuit add another 1 tick repeater, this is a side affect of the north-south quirk that has existed since like ever, essentially the series of event that the game goes through to propagate redstone is locked, when a block is powered it updated the block above first, then north and then south, then the block below then east and then west. so what's happening because of this is that the block is powering the piston before it powers the side that has the t-flip-flop piston, and by the time that happens, in the games mind, the block is already been moved and no longer is capable of updating the piston, the block is still physically providing power to the piston, however the piston isn't updated until the block is already moved, repeaters however can still pull the redstone current.

galaxy_2alex 2014-10-25T12:42:31Z

Is this still a concern in the current Minecraft version 1.8.1 Prerelease 3 / Launcher version 1.5.3 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

user-f2760 2016-03-18T16:11:11Z

No response for over a year.

6 more comments

DicoTheRedstoner 2016-03-20T15:44:29Z

Sorry, yes this is still a concern in the current version, however it has become slightly more stable.
I'm quite certain that it works reliably if the monostable is powered from 2 of 4 directions now, but it's definitely still in the game.

The preferred solution for me would be to make it not power any pistons, but still power repeaters.
Let me argue why:

Nearly every redstone contraption is made to not rely on unreliable bugs in the game, to ensure that it is not coordinate dependant, random, or direction dependant.
So nearly every redstone contraption is made to not use this monostable to power pistons directly, but this monostable is the most often used monostable in the game, so it is important that it will power repeaters. Fixing it this way will break next to no contraptions. Remember that most redstone creations take hours to complete, and some even months. Having to go back and fix them, which might sometimes be impossible, will take another large amount of time.

I know that this way of fixing it doesn't make much sense, but now you know why I prefer it, and I'm sure you can see my point.

Panda4994 2016-05-26T04:10:56Z

@unknown @unknown I can confirm that it is caused by the update order.
Currently: west east down up north south

Depending on if the piston in front or the one below get updated first the circuit behaves different.
It's impossible to avoid all directional behaviour because the updates need some order, but the y-axis shouldn't be updated in between the two other axis.
Because that causes everything that depends on something updating a y-direction before a horizontal one or the other way around, to be directional.

The question is: What order would be best?
Y-Last: west east north south down up
Y-First: down up west east north south
Y-Split: down west east north south up

I think it would make sense to keep the horizontal directions in the same order they have been before to minimize the things that would break. I also don't see any advantage changing it.
Of course you could also switch the places of up and down in all of these.

No matter how you change it, it would break some things that depend on update orders. They would be fixable though.

I made a mod that allows to set the update order with a command (E.g. /updateorder west east north south down up).
If you want to try how different update orders would behave you can download it here: http://www.mediafire.com/download/b9mjwuimu2ei7wg/1.9_UpdateOrder.zip
Video about it with a more general/theoretical approach: https://www.youtube.com/watch?v=aRr3NpmQiCg

wobst.michael 2016-10-29T20:32:02Z

Is this still an issue in the most recent versions (currently that is 1.10.2, or 16w43a) of Minecraft? If so, please update the affected versions and help us keeping this ticket updated from time to time. If you are the owner/reporter of this ticket, you can modify the affected version(s) yourself.

Panda4994 2016-10-30T00:45:36Z

I can confirm 16w43a.