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HP Forum Archive 20

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[wp34s] Using FAST and SLOW
Message #1 Posted by Les Wright on 1 Dec 2011, 10:53 a.m.

I was testing out the integration program I mentioned in an earlier thread when I noticed that things were taking almost twice as long to solve as when I began testing them. I thought I broke something in my program, but I when I reverted to an earlier version that I knew tested faster the slowing was still there.

Eventually discovered the FAST and SLOW commands in the manual. I thought FAST might override the calculator's propensity to drop into SLOW mode when battery voltage drops, but apparently not. I ran FAST, then started up the integration problem, saw the low-batt indicator flash for a bit, then go out, so I assumed the calc had adjusted and reverted to SLOW mode again.

Am I right in my observation here that it looks like SLOW can override FAST when batteries are fresh, but FAST can't override SLOW when batteries are lower? Also, where is the cut off point where the calc goes into SLOW mode. BATT told me I was running at 2.9V for a few days, but now it consistently reads 2.8V, so I am guessing that's the magic number?

TIA,

Les

      
Re: [wp34s] Using FAST and SLOW
Message #2 Posted by Walter B on 1 Dec 2011, 5:10 p.m.,
in response to message #1 by Les Wright

Making a long story short: Yes, SLOW can override FAST. And yes again, you can't set FAST if the battery voltage is lower than a certain limit.

            
Re: [wp34s] Using FAST and SLOW
Message #3 Posted by Les Wright on 3 Dec 2011, 3:48 a.m.,
in response to message #2 by Walter B

Quote:
Making a long story short: Yes, SLOW can override FAST. And yes again, you can't set FAST if the battery voltage is lower than a certain limit.

Thanks, Walter. The short answer is what I needed now. I was wondering why my program was taking almost twice as long to run. The processor is clocked to half the speed, which for simple calculations and fast programs is in itself more than enough.

Les

                  
Re: [wp34s] Using FAST and SLOW
Message #4 Posted by Dominic Richens on 3 Dec 2011, 7:27 a.m.,
in response to message #3 by Les Wright

if you are up to making Wiki updates as you learn stuff, feel free to update WP-34s Users' Guide. I know that the FAST and SLOW are not yet documented (like most stuff).

                        
Re: [wp34s] Using FAST and SLOW
Message #5 Posted by Walter B on 3 Dec 2011, 10:25 a.m.,
in response to message #4 by Dominic Richens

Quote:
I know that the FAST and SLOW are not yet documented (like most stuff).
Hmmh, not quite true: Both are documented in the manual (like almost all stuff) ;-)
                              
Re: [wp34s] Using FAST and SLOW
Message #6 Posted by Dominic Richens on 3 Dec 2011, 11:14 a.m.,
in response to message #5 by Walter B

yes, quite true - the owner's manual does have everything. I guess what I should say is that it would be good to capture the examples discussed in this forum somewhere - the Owner's Manual is not the appropriate place (otherwise it would be 1000 pages in no time).

I was dry-walling a trapezoidal attic wall in my house and trimming in an arched window. The WP-34s fraction mode was very, very useful, but I had to play with the DEN* modes a bit before I understood what you meant :-)

Hence I took the time to document what I figured out in the wiki..


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