Boolean Logic Sequencer Error

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Xeys42
Posts: 24
Joined: Thu Sep 02, 2021 4:58 pm

Boolean Logic Sequencer Error

Post by Xeys42 »

I made a quick patch demonstrating the following anomaly. If you look at the attached images the first one shows the And operator working as it should, i.e. the sequencer doesn't run, however, when I select Nor and Xnor the sequencer runs. This shouldn't happen as A is on and B is off which defies the logic, and yes I have pressed the stop button before changing the modes. I'm wondering if this is a bug. :!: Maybe it's something to do with the LFO :?: However, changing the rate doesn't change anything.
and operator
and operator
and.png (1.13 MiB) Viewed 97 times
nor operator
nor operator
nor.png (1.1 MiB) Viewed 97 times
xnor operator
xnor operator
xnor.png (1.09 MiB) Viewed 97 times
ColinP
Posts: 998
Joined: Mon Aug 03, 2020 7:46 pm

Re: Boolean Logic Sequencer Error

Post by ColinP »

This is the expected behaviour.

One of the inputs is disconnected therefore always zero, let's say it is the B input that's disconnected
so B = 0

Looking at the truth table for NOR

A B Q
0 0 1
0 1 0
1 0 0
1 1 0

Now when A (the LFO) is 0 the output is 1.
When A is 1 the output is 0.

With XNOR...

A B Q
0 0 1
0 1 0
1 0 0
1 1 1

Same result.

So in both circumstances the clock is just being inverted and the sequencer advances (albeit a half cycle out of phase).
ColinP
Posts: 998
Joined: Mon Aug 03, 2020 7:46 pm

Re: Boolean Logic Sequencer Error

Post by ColinP »

Also if your intention is for the LFO to control the tempo of the sequencer you need to feed its output to the sequencer's EXT CLK socket and engage the EXT button as shown below.

lfoAsClock.png
lfoAsClock.png (266 KiB) Viewed 66 times

You could then add an AND gate into this path to enable or disable the LFO's external clock signal (which is what I'm guessing you were experimenting with).

In your screenshots the LFO is just starting the sequencer and the sequencer is running on its own internal clock. So the only impact the LFO RATE knob will have is how quickly the sequencer starts.
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