CUDS EXPLAINED! Powerful But Forgotten Minecraft Java Redstone Component/Circuit

Many have seem to forgotten about CUDS, Comparator Update Detector Switch and it's ever growing uses. I hope this video sheds light on this circuit to inspire redstoners to create contraptions not otherwise possible.
It video will go over the Component that once had many former names: Tile Entity Data Update Detector (TEDUD), Tile Entity Update Detector (TEUD), Data Update Detector (DUD), Comparator Block Update Detector (CBUD), before deciding on Comparator Update Detector (CUD).
This is a Java exclusive feature so sorry bedrock players.
Timestamps:
0:00 Sample Use case with @Sipover !
3:48 How forgotten this tech is & how I found out about it
5:38 Video Scope and prerequisite info about BUDS
8:30 What is it?
9:50 How CUD works
11:26 All 50 use cases for CUDS
25:21 All known CUDS Designs
Outdated wiki: minecraft.wiki/w/Tutorials/Co...
Context Videos:
• Every Redstone Compone...
• INFINITE Furnace Fuel ...
• 3 Easy Auto Crafters t...
• Clarification: Air Blo...
Builds using CUDS:
• [1.16; 1.12+] CUD Base...
• Storage Tech: CUD Base...
CUD Designs:
• Minecraft - 21 Block &...
This 1 longer works • Minecraft | Pistonless...
• First Ever Pistonless ...
/ 116_cud_comparator_upd...
• Minecraft Compact 1x4x...
• Smallester smaller sma...
• Smallest Comparator Up...
• Tileable, Compact T-Cu...
• Minecraft: Silent Comp...
• Minecraft: Comparator ...
Music:
AI Music so no source
ambient1 of Mob vote 2023 • Soundtrack of Minecraf...
otherside minecraft.wiki/w/Music
ambient5 of Mob vote 2023 • Soundtrack of Minecraf...
Minecraft minecraft.wiki/w/Music
One more Day minecraft.wiki/w/Music
Labyrinthine minecraft.wiki/w/Music
wending minecraft.wiki/w/Music
infinite_amethyst minecraft.wiki/w/Music

[@mooing_cowmilk]

For those who wanted a world download or build tutorial of the door shown at the start, I've made a part since since I've designed a new silent CUD compacting it alot (old version is there too): kzbin.info/www/bejne/b3_HZnqEoqd_mpY

[@MTG_Music]

I had entirely forgotten these existed. The one with the cat has to be the most cursed redstone component ever.

[@Mmshh]

cactus storage

[@whocares2277]

Catstone

[@Fasteroid]

I still have nightmares about that cat

[@gavinford2277]

I don't think you mentioned it here, so I would like to add that tripwire hooks will give out a comparator update if another hook is placed facing it. It doesn't need string and there can be blocks in between

[@mooing_cowmilk]

that is cursed, basically a form of wireless redstone

[@biblebot3947]

How far apart does this work?

[@gavinford2277]

​@@biblebot394740 blocks in between the hooks; it's the same as the max length of a normal tripwire hook

[@mooing_cowmilk]

@@biblebot3947 in a reply on a different comment @yurrboi mentioned it was 41 blocks

[@THE1FIREHAWK]

Can there be air between?

[@dysphoricpeach]

i remember learning about this when etho made a detector rail pressure plate in hermitcraft, saying ‘this is what we used to use before observers’

[@nickyhenderson5203]

This is pretty useful for keycard systems utilizing the new decorated pots. You could do it before but not as easily

[@cubicmetre]

Certainly not a forgotten component, we have been using these in storage tech for years. There is a stateless design I use frequenty in contraptions to reliably count item throughput at hopper speed. Dustless filters for first item unloaders also make use of CUD which makes them robust against overflow in 1wt systems. Experienced technical players find it just as ubiquitous as any redstone component like a monostable or hopper clock.

[@mooing_cowmilk]

Interesting that those designs don't have their own video (as far as I know), since I didn't spot them on youtube or google when searching for CUDs. Nice to hear that they are used in designs just that they aren't a highlighted feature of it.

[@cubicmetre]

@@mooing_cowmilk Well, from our perspective highlighting CUDs would be like highlighting repeaters or pistons. It's just a common component at this point, not really worth getting too excited about.

[@mooing_cowmilk]

​@@cubicmetre I see your perspective, rarity is the eye of the beholder, as an expert it is common place similar to how a 12 eye is to a seed finder. The correct wording/phase I should've used is more about lack of documentation that exposes the concepts to a wider, more general audience. (plenty of videos explaining in depth pistons, repeaters, regular comparators, mono-stable, T-flip-flop, etc)

[@auxchar]

​@@cubicmetreIs there a good resource for the fundemental building blocks used in storage tech like that? There's a lot of people not too involved in that community, and even if you're moderately experienced in redstone, some of the things you guys use on a regular basis seems like black magic to us mere mortals.

[@mooing_cowmilk]

Completely Editing this comment. After using a search engine to check all videos transcripts on KZbin, CUD has only been mention a total of 29 times (not counting this video) (still need to check other unused names), found the examples you mentioned. This compared to hopper clock (3.4 k videos results), and monostable (6.3 k videos). Although it may be commonplace in storage tech, outside of that is a nope.

[@greenstonegecko]

This NEEDS more mainstream attention. This is powerful tech

[@mathpuppy314]

I remember making a secret base in like 2018 using a furnace CUD. This actually brings back nostalgia.

[@ianw.48]

Pretty good overview of these. I think I was first introduced to these by Doc in his LP. Think he also used one for a door key to detect anytime an item frame was rotated back in Hermitcraft S3. This application would be trivial with an observer nowadays but was pretty cool at the time. Really prefer the term C-BUD even if it is a bit inaccurate, CUD just sounds awful to say imo :)

[@Pockeywn]

DUD is so much more fun

[@D_4_N_]

im on the DUD train@@Pockeywn

[@yurrboi]

This rediscovered + crafters being added?! Redstoners finally getting spoiled out here

[@circuitgamer7759]

I always love learning new technical details I didn't know :) I'll be experimenting with this at some point after I finish my current Create experiments.

[@8bit_pineapple]

Very cool :). I was going to make The Cave of Wonders from Aladdin. Definitely using this with a sign saying "Only those who take nothing can enter."

[@coinbongo4694]

Even though I barely play minecraft anymore and I found this redstone knowledge really cool. It makes me want to experiment a bit again. Cool video!

[@seccuenta50ydos]

I know a lot about minecraft features including strange ones but you managed to show me an entirely new thing to me. Good work!

[@149315Nico]

This is what I call quality content. Thank you very much for the hard work, I’m looking forward to implementing some of these use cases on the next Server I’m gonna play on

[@samstade5598]

bold of you to put a respawn anchor in the middle of your test world

[@itsnotmedylan]

this is really cool, thank you so much for detailed but fun explanation!

[@feeqsforge]

Fantastic video man! I was completely unaware of this circuit

[@PeChips]

That was so interesting, I'd never heard of CUDs before and the video explains it very well !

[@Dave-cg9li]

I used t love playing with these! But the old design I was using got fixed and I assumed that maybe the whole mechanic got removed! I'm so glad it's still in the game 😄

[@Fireheart318]

I had no idea this existed! Super useful!

[@JinJoxx]

This is really cool! I hadn’t heard of this before.

[@jadesprite]

A long time ago I found a very old version of this (probably from Ray) and built it on my f&f server, then immediately forgot what it was or how it worked and it just sat there like a monument for 2 years. We all just sort of danced around it until I decided I had to figure it out, and realized the power. So then I started going around to all my bases to try to fit it into them ^^ Nice to see an in depth review on how all this works

[@fgvcosmic6752]

This is amazing. I cant believe how many old problems I had this wouldve solved! Agh, I remember trying to figure out how to do this with regular BUD, but to no avail D:

[@tpyk_mahn]

Really interesting video, fells like my understanding of redstone just shot up

[@KM____________]

the server I play on will teleport drops to reduce lag and this may have shown me how to get around it and fix my farm. lots of applications, very cool. liked, subbed, saved- thank you. if u didnt know, u might be interested to know that standing on string without triphooks counts as block updates- so you use it as a pretty invisible pressure plate.

[@dreamer5959]

I remember Cubfan used something like that where he would click inside of a button to activate something. I can't recall what it did though, it was in Hermitcraft season 5, like 6 years ago lol.

[@hoagieland3716]

I’ve actually used this about 5 years ago at this point to make a programmable 5-button combination lock. It can be quite handy for a bunch of different kinds of contraptions, but CUDs seem pretty much forgotten for some reason

[@de_g0od]

thank you for making this! I have been trying to tell people about this for years but nobody seems to care haha

[@bottomtextdanny3050]

by the thumbail i thought CUD meant Cat Update Detector

[@westonschurig4969]

Wow, this is a feature I've never heard about. I think I'll use this for a secret passageway in a build some time.

[@mooing_cowmilk]

Minor info when you do. I had a regular comparator hooked to the chest as well making it so it so the chest had to be empty to work. Otherwise taking/inserting any item(s) would trigger it since your clicking in it. Who would click on an empty chest anyways? was my thinking

[@westonschurig4969]

@@mooing_cowmilkThanks! That probably would have stumped me for awhile while trying to make it work.

[@Toots_Thielemans]

Fascinating!! I'll definitely be using this. I was curious (not sure if I missed this in the video/comments), but is this the same (or similar) mechanic at play in ilmango's "Why You Need A Chest To Make A Proper Hopper Minecart Item Filter"? (tldw of that video: chest with 1 item and a blocked hopper below will allow a hopper minecart filter to update its signal properly)

[@mooing_cowmilk]

Yep, that is correct. Comparators have have a 1 sec delay (I think), from updating when it comes to rails, so it is a temp CUD, the hopper & chest sends constant updates to remove the CUD property. In my CUD video part 2 I used this trick to design the first completely silent CUD

[@Toots_Thielemans]

@@mooing_cowmilk - I just finished watching it!! Thanks for these videos and your explanation!!

[@anamoyeee]

WHAT? That has so much potential and i have never heard of it

[@deadlydirtblock7698]

Oh man, I was expecting this to be on the confusingly named CBUD (collision box update detector) discovered by pi and zgooh back in the day Great video, I'd forgotten these existed lol

[@mooing_cowmilk]

Wow that was a blast from the past, forgot that existed apart of the defuse bomb challenge. Might to too advanced/tricky to fully understand unlike the CUD.

[@mooing_cowmilk]

Looked into there, there is a total of 3 videos mentioning of it's existence, the bomb one, an unlisted video, and a deleted video only found on waybackmachine. temped in the future to make a video on that but change it's game to PFUB (Path Finding Update Detector) since it feels like making a family of BUD (general term, C-BUD - cmomparator, PH-BUD, etc)

[@deadlydirtblock7698]

@@mooing_cowmilk there are several more in pi's unlisted videos playlist, including a couple from 1.16 and 1.17

[@mooing_cowmilk]

@@deadlydirtblock7698 can you link it please, I can't find it. I only found one of the 1.16 ones

[@deadlydirtblock7698]

@@mooing_cowmilk kzbin.info/www/bejne/op7HhqGol7GfaMk This is the 1.16.5 one, he links a 1.17 one in the comments of that, and nooticus references a previous 1.15 one (I haven't watched all these videos so idk exactly how much detail they go into)

[@watchedsmile]

This just brought back an ancient memory of inventing chunk detectors. It was on an old version of the xbox 360 and could detect any block updates in the entire chunk it was in. I wonder if its possible to make one on java. It was right when observers were added but they used to work differently on xbox 360

[@mooing_cowmilk]

CBUD (not to be confused with CUD) might have the same behavior (Collison box update detector)

[@ScubaKay]

Gonna save this for when I inevitably make an escape room on our SMP!

[@brickie9816]

Yeah, "forgotten" fits pretty well lol. I always knew about them and kept this information in the back of my head but never knew of their power. I always thought it's just a quirky BUD.

[@GwnTim3]

13:16 he knows CUD’s, some next level redstone, but then proceeds to not know you can safely charge a respawn anchor in the overworld

[@mooing_cowmilk]

Not if you click it 5 times

[@GwnTim3]

@@mooing_cowmilk oohhhh, it detects you setting your spawn? Cuz then sorry, my bad

[@mooing_cowmilk]

@@GwnTim3 tested in survival in the nether, dying triggers it can refilling does too

[@rhueoflandorin]

Great video.

[@tzisorey]

Oh, I remember these...vaguely. There were some videos out there, but they seemed to vanish, so I figured it was patched out. What concerns me more, is that I'd also completely forgotten that redstone torches can 'burn out' - has it really been that long since I've experienced that?!

[@mooing_cowmilk]

I think the torch burn out is more well known since anyone who tries an as fast as possible circuit would get an unwanted one. Main use is using 3-4 in a burnout clock for tiny farms etc

[@xxseesxx9234]

i love to build the old sugar cane farm design using budded pistons and a comparator, i never understood the comparator situation fully

[@jaroslavpro8401]

i didn't even realise the fact i been using this method as sugarcane farm(it uses CUD from furnace to detect block update,in this case sugarcane, or bamboo then outputs a redston signal to pistons, also need one sand on piston to reset state of piston), bc i been using simple farm i found on youtube years ago

[@Bearcrapsinwoods]

There is something satisfying about seeing cats have a use in redstone😻

[@FearlessDudeiscool]

In the beginning with Sipover he was take stuff from the chest and putting stuff in, how did you only make the door open only when he clicked the slot and not transfer items?

[@ArthurAkhadov]

For the bud explanation would have been nice to show the same demonstration with doors, as quasi connectivity sprung from the fact that doors game code has been reused for the pistons game code. At least that's what I heard, but I haven't seen anyone demonstrating it hands on in a video for some reason. 6:55

[@MythicNinja]

Hey question, How did you make the machine in the start that only detects when they click on a slot and not put in or take out items? also does that machine also not detect when you break the chests. In other words it only detects when you click a slot..

[@mooing_cowmilk]

Video with Tutorial and world download kzbin.info/www/bejne/b3_HZnqEoqd_mpY

[@rick-sanchez]

Would be interesting if the mine cart "clock" stops in non entity processing chunks. There are easier clocks for that but it may have a use case.

[@fahlur9880]

cud is a very old term, it almost fell off the grid a bit because no one really used it. Nice rediscovering for people :p

[@whocares2277]

I played around with the door logic (shown around 3:35) and made it much more compact. The slime blocks are unnecessary, you can let the piston directly push the cauldron. Let the observer output go into a 2 tick repeater that powers a redstone torch, make the (chest-reading) comparator output go into a 1 tick repeater, connect the output of the torch and that repeater. Keep the 1 tick repeater on the floor that locks the piston when the chest is filled and keep the redstone torch on the floor that's part of the CUD. That's all you need. 2 comparators, 3 repeaters, 2 redstone torches, 6 deep 5 wide 5 high. The output is powered by default and only gets unpowered when someone clicks in an empty chest.

[@mooing_cowmilk]

The reason why I used slime so it was slient from the front not giving pistion sounds clue when someone is messing around with the chest. Is it still slient?

[@whocares2277]

@@mooing_cowmilkFor me it's not completely silent in either version. It's louder with the piston so close, no doubt. It can be made silent if you force the player to stay 2 blocks away from the chest.

[@Ishbosheth.]

Fascinating.

[@Waffle_6]

really cool

[@telotawa]

wait how do you make it detect only some updates and not others? shouldnt the "click empty slot" one as the demo also detect all the items moving around?

[@mooing_cowmilk]

had a normal comparator hooked up to the chest as well blocking the CUD. so the CUD output only goes to the door when the chest was empty

[@wollebay]

very interesting

[@yurrboi]

I found that the CUD can detect activity through a single hook and string(s) unattached to another hook, although the detection is locational... Only working if the hook is facing North or East

[@yurrboi]

Unrelated and probably not useful at all.. Hooks can detect another hook being placed facing towards it, up to 41 blocks away, not locational. Maybe a vanilla adventure map to activate something behind the scenes at a specific point?

[@Mmshh]

There is a moderately old video on this wireless redstone. It works with a normal bud too. I never thought about the fact that a cud would work too.

[@10carries]

How did the chest at the start not detect sipover taking and putting stuff in the chest? Doesn’t a cud detect putting things in and out as well as clicking the slots?

[@mooing_cowmilk]

Had a normal Comparator also connected to the chest as well blocking the CUD from outputting. Made it so the chest had to be empty for the CUD to tell the door to open.

[@10carries]

@@mooing_cowmilk thanks!

[@mooing_cowmilk]

@@10carries Incase you need for help, make a video on it: kzbin.info/www/bejne/b3_HZnqEoqd_mpY

[@gavin5410]

For your cat version with the waterlogged chest, will the cat try to teleport to the player that tamed it when the water is out?

[@mooing_cowmilk]

as far as I know it doesn't. I remember player detector using pet tp but it doesn't appear that the cat does

[@t-kamui7275]

sculk sensor with CUD is OP

[@RawFish2DChannel]

I didn't even knew these existed

[@nartoomeon9378]

COOL!!!

[@googooblabla100]

At the start of the video, how did you isolate the pulse so the door only opened when you clicked on the empty slot?

[@mooing_cowmilk]

Use two repeaters, one in the CUD, the other a normal comparator. make the Normal Comparator block the output from the CUD so it only allows the signal to pass if empty

[@mooing_cowmilk]

If your still confused, I did a video for it now: kzbin.info/www/bejne/b3_HZnqEoqd_mpY

[@neaputbutter]

Im curious as to what the redstone community will do with this!

[@bottlewisp]

and here i thought you redstoners were smart for finding shrewd ways to detect contents of containers, etc.. while never mentioning this super detector, trivializing a ton ;P the possibilities though... damn :D

[@qualliez]

if you do this with a tripwire and another one mirrored up to 40 blocks away you can get wireless redstone up to 40 blocks in a straight line

[@0oSCHMILLENo0]

It's so wierd how in-depth people go into what are essentially bugs in the game. You have basically created an academic thesis on the subject of CUDs lol

[@nel_tu_]

not a bug

[@0oSCHMILLENo0]

@@nel_tu_ this is obviously not the intended behaviour of the comparator

[@nel_tu_]

@@0oSCHMILLENo0 its a feature

[@0oSCHMILLENo0]

@@nel_tu_ was it intended by the developers?

[@renderproductions1032]

I feel like C-Bud is a better name since it is very similar to a normal BUD.

[@Hazy_Heart]

13:22 Does this mean you could make a trapped cake? That sounds great for multiplayer >:) 14:57 That sudden speed up really startled me. You should be more careful with sudden speed ups like that

[@de_g0od]

is there a silent automatically resetting design

[@sky_0f_blue979]

a little funny seeing you go over some incredible redstone tech but still not know how respawn anchors work

[@mooing_cowmilk]

yeah, never really used it since overworld most of the time

[@Zalazar_Axath]

@ThatMumboJumbo here is something super obscure about redstone that, according to this video, you do not know

[@filthychurch]

Tutorial for that door at the start?

[@rame.]

cool

[@GradientAscent_]

It sends updates every time NBT data changes?

[@mooing_cowmilk]

basically yea

[@Wily_Wendigo]

When i try to build this, it's infinitely stuck looping?

[@mooing_cowmilk]

if your doing this on bedrock edition it doesn't work on there

[@Wily_Wendigo]

​@@mooing_cowmilk No I am on java. I got it to work for me by having the observer power the item on top of my piston, instead of the piston

[@nieboniebieskie3502]

how did you make this so it's only detects players touch?

[@mooing_cowmilk]

Also hook up a normal comparator to the chest making it so the chest has to be empty too for the door to open

[@nieboniebieskie3502]

@@mooing_cowmilk thanks

[@mooing_cowmilk]

Video with Tutorial and world download kzbin.info/www/bejne/b3_HZnqEoqd_mpY

[@zakari_rai]

Cake theft alarm :0

[@AB-Prince]

I'm just thinking of tnt going off from someone editing a sign

[@katofffel4387]

That isn't sipover, that's someone with sipover's head

[@arkaprabhonath1509]

3:43 "sOmEoNe nEeDs tO mAkE aN eScApE rOoM"

[@kadenspencer-smurthwaite9006]

Have a like

[@jakobherbst4789]

Liked, Subscribed and kindly Asking for a world download

[@mooing_cowmilk]

All the CUD designs are 2D so one can rebuild them using just looking at the video. For mutlple of them they have their own videos on youtube already (credit of channel name and video is in discription). If your refering to the door at the start of the video, that was poorly built (just mock up use case), it should be redesigned to be much better

[@jakobherbst4789]

@@mooing_cowmilk Yea i copied a few of them, but you did such a great job compiling them all, it would be a shame if this reference world got lost. For me it would just be cool to mess around with the different designs and see which one i like best for a secret entrance.

[@NeverSnows]

4:00 tf you mean by "even mumbo jumbo"? Like, if you said "Even Crafty doesn't know it" or "Even Gnembon doesn't know it" it would make sense.

[@mooing_cowmilk]

I had hard evidence that mumbo doesn't know it (and recent too), unlike the other creators

[@NeverSnows]

@@mooing_cowmilk Quite understandable, but unfortunate nonetheless;

[@Highlandword9]

Oh are these DUDs?

[@mooing_cowmilk]

Data update detector was an name used back in the day when the community was choosing the name for it. CUD won out (comparator update detector)

[@Highlandword9]

@@mooing_cowmilk ahh I see, guess I'm old :]

[@SpaceSoups]

trapped untrapped chest.

[@mattssheep4]

Isn't a CUD a variant of BUD?

[@mooing_cowmilk]

Every CUD is a BUD but CUDS additionally detect many more things that a CUD could not. This was explained in the video, guessing you didn't watch it all before commenting

[@hawkeyeentertainment494]

world download?

[@mooing_cowmilk]

For the door, provided in part 2: kzbin.info/www/bejne/b3_HZnqEoqd_mpY

[@MrTylerNinja]

Bedrock?

[@mooing_cowmilk]

No, doesn’t work on bedrock at all. All you get is a clock

[@Nathouuuutheone]

11:15 excuse me?? Since when do comparators spin like that?? You're just gonna put that on screen and not even address its existence??

[@mooing_cowmilk]

The spinning was an visual aid of what the comparator in the CUD is doing under the hood. I just used command blocks for that to help understanding. Sorry for any confusion

[@Nathouuuutheone]

@@mooing_cowmilk thanks I was so confused hahahaha

[@linse6388]

Mincrafters are just build diffrent

[@HelPfeffer]

"they all broke on the new snapshot" 🥺❤️‍🩹

[@mooing_cowmilk]

Just checked on 1.20.3 Pre prelease 1 (latest snapshot) and it still works so no clue what you are referring to

[@HelPfeffer]

​@@mooing_cowmilkOh, no, I meant this moment: 32:04

[@supermagma]

hehe. milk. cow. cud