# How do redstone torches (circuits) work in Minecraft?

I tried reading the minecraftwiki page on the subject, but without an understanding of precisely how the torches work, none of it makes sense. I have a lot of questions, so even an article explaining only a few of the answers would be helpful.

• How is it possible for the torches to work as both input and output to a circuit?
• What if two torches are both acting as output to the same redstone-wire?
• What if one torch is outputting positive/on/true to a redstone-wire but another is outputting negative/off/false to the same wire?
• Is there a practical difference between torches on the ground and torches on the wall?
• When people talk about 'the redstone-torch's block' (ex. wires only carry power 15 blocks from the source block), do they mean the block the torch is attached to, or the block of space the torch is occupying?
• How do I read the diagrams on the minecraftwiki page?

Thanks for any help understanding all of this!

• Re: The Diagrams on the MinecraftWiki page: They were created with MCRedstoneSim, a simple tool for planning and experimenting with Redstone Circuit Logic outside of Minecraft. They are basically simplified top-down views of an ingame circuit. Oct 12, 2010 at 18:07

Bob's Minecraft Tutorial, linked by Billy ONeal, is a useful resource, but I'll try to put the basics into words.

How is it possible for the torches to work as both input and output to a circuit?

Is there a practical difference between torches on the ground and torches on the wall?

Depending on where the torch is placed, neighboring blocks will be inputs or outputs, but each neighboring block is EITHER an input or an output - no blocks are both.

• A torch on the ground (in other words, on top of a block) outputs power in the 4 cardinal directions, and also outputs power to any block in the air above it.
• That torch will only accept input from the level below it, so input wires must run straight into the block the torch is sitting on.

To summarize, torches on the ground output to their level and input from the level below.

• A torch on a wall (in other words, on the side of a block) outputs power in only 3 directions (it doesn't output back into the block it's mounted on).
• That torch will accept input from the top of the block it's mounted to, and from the other 3 sides of the block it's mounted to.

In summary, torches on a wall output onto the ground and take input through the wall block.

What if two torches are both acting as output to the same redstone-wire? What if one torch is outputting positive/on/true to a redstone-wire but another is outputting negative/off/false to the same wire?

This has been answered elsewhere, but: If any power source hooked up to that wire is on, the wire will be lit up.

How do I read the diagrams on the minecraftwiki page?

Again, I'll try to break down the basics:

• White squares are just air, nothing special
• Yellow squares are blocks
• Dark yellow squares are blocks a level below (that is, they're an abbreviation for "white on this level, yellow below")
• Grey squares are blocks on the current level with other items a level below

White and yellow squares can then have these items on them:

• Red lines are wires
• Red circles are redstone torches (which may be attached to the side of a block or sitting on one)
• Grey circles are levers
• Small dark grey rectangles are pushbuttons
• Large grey inset squares are pressure plates

So, for example:

• a red line on a yellow background is a wire on a block
• a grey circle on a yellow background is a lever on a block
• a red line on a grey background is a block over a wire
• a grey circle on a grey background is a block over a lever

Within the MCRedstoneSim program you can change levels and see the wiring and such on each level of the circuit, but these extended types of blocks exist so that the whole circuit can be communicated with one set of symbols and no need to show diagrams per level.

• Awesome! Another good link: kyon.pl/static/img/remiq.net_16582.jpg Oct 12, 2010 at 22:00
• That image is a nice one, very cool. Oct 12, 2010 at 22:09
• Torches provide power in all directions, including above and below, except the block the torch is attached to. So a torch hanging on the side of a block transmits power above, below, away from the block, and to the side. A torch standing on top of a block transmits power above, and to all four sides. Dec 20, 2010 at 15:52

How is it possible for the torches to work as both input and output to a circuit?

Watch this

What if two torches are both acting as output to the same redstone-wire?

The wire will be on if either torch is on. Note that actually achieveing this requires a T-junction because redstone wire needs to point in the direction of any sources or sinks.

What if one torch is outputting positive/on/true to a redstone-wire but another is outputting negative/off/false to the same wire?

Isn't that the same question? :P

Is there a practical difference between torches on the ground and torches on the wall?

See the video.

the redstone-torch's block' (ex. wires only carry power 15 blocks from the source block), do they mean the block the torch is attached to, or the block of space the torch is occupying?

Neither. They mean number of blocks of redstone wire. I.e. the initial redstone powered by the torch is the first one off your 15 counter.

How do I read the diagrams on the minecraftwiki page?

No idea. Sorry :(

• I watched that already, but I am still confused - I guess I just need someone to spell it out in text. In the meanwhile, I will watch the video(s) again. Oct 12, 2010 at 18:15