OSDev.org

Posted: **Wed Mar 20, 2013 3:38 pm**

nobody actually does this

The thing about electronics is that ANDs and ORs (of any input width) can be implemented with just diodes (the resulting gate depends on the direction you use said diodes), and a NOT equates to a single transistor, thereby covering your primitive silicon components. NANDs and their kin have no such equivalence and are implemented as compositions of the other three parts.

Posted: **Thu Mar 21, 2013 1:20 am**

Hi

Love4Boobies wrote:No? I don't know where I got that from; I should take one of Coursera's courses on these matters. In that case, I don't know what the most common operation is when working with logic gates or whether one can be singled out.

I disagree. The single most frequently used bitwise operator is "unary is". Most people aren't aware of this bitwise operator, so here's the truth table:

Code: Select all

in | out
------
1  | 1
0  | 0

In software this operator is used for assignment (e.g. "x = y;" relies on "unary is"). In electronics, for every conductor (of non-zero length) there are an infinite number of "unary is" operators involved.

Cheers,

Brendan

Posted: **Thu Mar 21, 2013 7:43 am**

That makes sense, Brendan.

Posted: **Sat Mar 23, 2013 5:27 am**

Combuster wrote:
nobody actually does this
The thing about electronics is that ANDs and ORs (of any input width) can be implemented with just diodes (the resulting gate depends on the direction you use said diodes), and a NOT equates to a single transistor, thereby covering your primitive silicon components. NANDs and their kin have no such equivalence and are implemented as compositions of the other three parts.

There are many ways to implement gates in electronics. The most popular method today is CMOS, where it takes two transistors to implement NOT for instance. DTL, while used, is not nearly as relevant.

Posted: **Thu Mar 28, 2013 4:39 am**

Brendan wrote:In electronics, for every conductor (of non-zero length) there are an infinite number of "unary is" operators involved.

Hahaha, very nice, Brendan. Some smart donkey had to point it out

Speaking of logic gates, my father has one of those Pong games that you plug into the TV. It's got two pots on it - one for each player's paddle. There's no software involved in it at all; it's entirely hard coded in a large series logic gates. Yep, back in the 70s and 80s, you could literally buy a 'Pong Chip' off the shelf at the local D ick Smith (damned profanity detector originally got rid of the d ick part) store (basically Radio Shack if you're in the US).

Maybe I should upgrade to CMOS and raise the clock speed on that baby!

Perhaps I could then create another unit to act as the two players and keep the ball in play as long as possible..... hardcoded in logic gates of course

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Most frequently used bitwise operators.

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Re: Most frequently used bitwise operators.

Re: Most frequently used bitwise operators.

Re: Most frequently used bitwise operators.

Re: Most frequently used bitwise operators.