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HP Forum Archive 21

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Documentation bug in original 15C manual
Message #1 Posted by BruceH on 1 May 2012, 4:18 p.m.

I couldn't find a list of known bugs in the original manual so sorry if this is not new.

Only minor but page 24 of the 15C Owners Handbook says "Pressing [g][pi] places the first 10 digits of pi into the calculator."

However, strictly speaking, the calculators (both original and LE) do not do this. Instead [g][pi] places a rounded to 10 digits approximation to Pi into the calculator. (And the example on page 62 gets this right.)

      
Re: Documentation bug in original 15C manual
Message #2 Posted by Luiz C. Vieira (Brazil) on 1 May 2012, 5:13 p.m.,
in response to message #1 by BruceH

I'd also add that the digits are placed in the X-register, not into the calculator as in some unknown place... (I still have my head back in the 80's, when manuals usually cleared issues instead of bringing them in...)

      
Re: Documentation bug in original 15C manual
Message #3 Posted by Mark Storkamp on 1 May 2012, 5:14 p.m.,
in response to message #1 by BruceH

Quote:
I couldn't find a list of known bugs in the original manual so sorry if this is not new.

Only minor but page 24 of the 15C Owners Handbook says "Pressing [g][pi] places the first 10 digits of pi into the calculator."

However, strictly speaking, the calculators (both original and LE) do not do this. Instead [g][pi] places a rounded to 10 digits approximation to Pi into the calculator. (And the example on page 62 gets this right.)

Actually, it doesn't put it into the calculator either. It's already there. Rather it moves it into the X register. Or better yet it makes a copy of the constant rounded to 10 places and puts it into the X register, which is really a BCD representation of the decimal number system, and not the actual number itself. (assuming of course it doesn't calculate it on the fly)

            
Re: Documentation bug in original 15C manual
Message #4 Posted by Luiz C. Vieira (Brazil) on 1 May 2012, 6:51 p.m.,
in response to message #3 by Mark Storkamp

Quote:
(...) BCD representation of the decimal number system, and not the actual number itself. (assuming of course it doesn't calculate it on the fly)
Interesting perspective... If we are talking about memory usage versus program instructions (time to compute being a factor, too), how many digits of a constant (two digits = 1 byte) would be worth computing instead of storing in system memory? There must be a break even point...

Cheers.

Luiz (Brazil)

Edited: 1 May 2012, 6:55 p.m.

                  
Re: Documentation bug in original 15C manual
Message #5 Posted by Steve Simpkin on 1 May 2012, 7:44 p.m.,
in response to message #4 by Luiz C. Vieira (Brazil)

Quote:
... how many digits of a constant (two digits = 1 byte) would be worth computing instead of storing in system memory?
42
(Sorry, couldn't resist)
                        
Re: Documentation bug in original 15C manual
Message #6 Posted by Luiz C. Vieira (Brazil) on 1 May 2012, 9:25 p.m.,
in response to message #5 by Steve Simpkin

Long Live 'The Hitch Hikers' (it will end in tears...)

(neither could I)

GREAT! Loved it!

Edited: 1 May 2012, 9:27 p.m.

      
Re: Documentation bug in original 15C manual
Message #7 Posted by Mike Morrow on 1 May 2012, 5:37 p.m.,
in response to message #1 by BruceH

So that's why I've been getting all those wrong answers! :-)

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