Gates on a Budget

[Yunru]

Ignore the title, this is more about gate building. Although depending on your number of inputs, you might save resources .

 

First, the OR "gate" a.k.a. connected wires. That's literally it.

Second, the NOT gate. No way around this one, just gotta build it; and without it we can't make any of the others below.

The buffer gate: Comprised of two NOT gates, this stops a signal flowing backwards.

The AND gate: Each input connects to it's own NOT gate. All of them then feed into a single NOT gate.

[chemie]

how are three NOT gates better than one AND?

[Yunru]

23 minutes ago, chemie said:

how are three NOT gates better than one AND?

It's not. But it uses less wire per input, so at higher levels it's cheaper.

It's also far more compact.

For N inputs, AND gates take up 4(N-1) spaces, vs. 2(N+1) spaces, to say nothing of the amount of wire taking up space.

[Saturnus]

I posted a thread about a similar topic a while back

 

[Arcus2611]

 

2 hours ago, Yunru said:

 

The buffer gate: Comprised of two NOT gates, this stops a signal flowing backwards.

 

Personally I just use a single buffer or filter gate in cases like this. If you don't mind the short delay it's more compact.

 

2 hours ago, Yunru said:

The AND gate: Each input connects to it's own NOT gate. All of them then feed into a single NOT gate.

If you're using sensors, you can actually make do with a single NOT gate in many cases. For example, I have an aquatuner that I want to disable when the ambient temperature goes over 95 degrees or the coolant goes under 20 degrees--I just hook both sensors up to the same NOT gate and flip the active conditions on the sensors.

 

This is technically a NOR gate but practically achieves the same effect as an AND gate.