SergeModular

-------------- Original message --------------

The easiest way to make a NAND gate is to NOT and AND gate. However, on the BLOG there is only one and gate so I had asked how to make another NAND gate from the remaining modules. Yannis shows how to make a NAND from 2 NOTS and and OR. However, Since one of the NOT modules is used in the creation of the first NAND gate, another one needs to found to make a second NAND gate.

As far as the charts go, think of the 1�s as a voltage present and 0�s as no voltage. So, from the chart a NAND gates outputs voltage in all cases except when there is voltage on both inputs. So, while the same results are gained from OR�ing two NOT gates, the same result is achieved by NOT�ing an AND.

A B A+B NOT(A+B)

1 1 1 0

1 0 0 1

0 1 0 1

0 0 0 1

The bigger question in your mind is probably, �Why do I want a couple of NAND gates anyhow?� The reason is that you can construct a flip-flop from 2 NAND gates. By feeding the outputs of the NAND gates into the input of each other, a basic memory module is created. In particular I would like to make a toggle flip-flop. This is a flip flop that when pulsed outputs a constant voltage (high or low, 1 or 0) until it is pulsed again. If the steady state is high then pulsing it makes it low. The usefulness is that it *stays* high or low until pulsed again. If I can�t figure out how to wire one of these up, I�ll have to get out the soldering iron and make a bunch of these as I�m constantly wanting one for complex sequencer work!

Clear as mud?

James R. Coplin

***************

If anyone asks of my whereabouts,

simply tell them i've gone out the window

for a spot of tea and am not

expected back any time soon.

***************

From: darkstr1746@... [mailto:darkstr1746@...]
Sent: Friday, October 01, 2004 9:11 AM
To: SergeModular@yahoogroups.com
Subject: Re: [SergeModular] Digest Number 721/NAND gates

I'm sorry, but i'm a dumb ass. Is there another way to explain this. I just don't get it.

kind regards

john duval

-------------- Original message --------------

Hi James,

to construct a NAND gate you have to OR two NOT gates:

The truth table for NAND is

A B A NAND B

0 0 1

0 1 1

1 0 1

1 1 0

Now:

A B NOT A NOT B (NOT A) OR (NOT B)

0 0 1 1 1

0 1 1 0 1

1 0 0 1 1

1 1 0 0 0

The cool thing about the BLOG module is that there are two NOTs so you can actually construct the above gate easily.

I hope this helps!

Yannis

From: "James R. Coplin"
Subject: RE: Re: Sequencer length double.... Chris ?

Anyone successfully wired up a flip-flop with a pair of blogs? I only have
the ons blog so I can't try it. Alternately, can a nand gate be constructed
with an or, xor, not and some other modules?

James R. Coplin

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