Final Rocket Challenge Comment & Survey

For confused, a Gray Code is basically a sequence of distinct values where only one binary bit changes state from one value to the next. They're useful in encoders and the like.

-- Erik

Reply to
Erik Horstkotte
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Jerry Irvine wrote in news: snipped-for-privacy@corp.supernews.com:

Hint: look at the binary representation of the numbers in the sequence, and see how they change from each to the next.

Extra points if you can then infer why this encoding is useful.

len.

Reply to
Leonard Fehskens

Requires gray hair to recognize it? How about Huffman coding?

-John

Reply to
John DeMar

Yup, that's what makes him 'irrational'! ;)

-john

Reply to
John DeMar

I do. tis a very reliable way to count

Reply to
tater schuld

binary counting in a way that only one bit changes state per count.

so do I win the 2,500 Quatloo prize?

Reply to
tater schuld

I know all about gray codes and Karnough maps, but I've never had to use them. Actualy I did use Karnough maps to structure the logic used in a seeker simulation logic, but the code ran slower than the existing spagetti code; too slow to use.

Alan

Reply to
Alan Jones

Gary wrote in news:3FB59531.9070303@below:

Nope, but Subrahmanyan Chandrasekhar may have...

sooner dot boomer at gbronline dor com

Reply to
Dan Major

Specifically, they are useful when you can't risk having an intermediate value accidentally decoded as the value you are looking for. Like in a rocket launcher!

Say you implement a digital launch controller that counts down from 10 to 0. During the transition from 8 (1000b) to 7 (0111b) it's possible that the 8 bit turns off a few nanoseconds before the 4, 2, and 1 bits come on. In fact, given the design of a binary counter, it's likely. What would happen if your zero decode saw that brief signal and fired early?

So instead you design your counter to use a gray code, where only 1 bit changes each interval.

1111 1101 1100 0100 0101 0111 0110 0010 0011 0001 0000

I remember designing such a counter back in digital electronics class. I don't recall it being more complicated than a normal binary counter. Nor is the decode logic. It's just internally different.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Reply to
Bob Kaplow

kaplow snipped-for-privacy@encompasserve.org.TRABoD (Bob Kaplow) wrote in news: snipped-for-privacy@eisner.encompasserve.org:

Oh! Oh! Oh! Pick me! I know!

Reply to
David W.

We'll launch on 1. Five - Four - Three -

Wait! Do you mean Five - four - three - two - one - then lauch (on zero), or lauch coincident with "one"?

On one. Five - Four - Thr - WOOSH!

What!!! Nobody launches on three!

I got tired of waiting.

Reply to
Alan Jones

On Fri, 14 Nov 2003 17:06:22 -0600, In the heat of the moment, "John Stein" posted: .

Apparently, you did not know Violet. :)

-- Bill

I am a member of the rabble in good standing. -- Westbrook Pegler --

Reply to
Bill Schowengerdt

V, IV, III, II, I .... uh, oh; can't launch!

We haven't imported the Arabic concept of "Zero" yet!

Reply to
Anonymous

ROFL! I bet you do and now I'm purple with envy. :-)

John

Reply to
John Stein

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