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Decimal points on my HP-25 are plentiful! - Printable Version

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Decimal points on my HP-25 are plentiful! - vaklaff - 09-05-2020 04:35 PM

Hello!

By coincidence, in this very week of the HP-25 anniversary I happened to run into a rather beaten unit. Since it was cheap and I had no pre-LCD HP, I took a chance a bought it. TBH I didn't expect much, it was dirty, had no adapter, the battery unit was slit open and empty and I couldn't try it out before the deal. But anyway. Today I cleaned it up a bit, inserted two alkaline AAs (I know it exceeds the designed input but I read it worked OK for a few people) and switched it on. Turns out it works fine for the most part:
  • no missing segment on the display
  • various stack and math functions I tried work fine, as far as I can tell
  • I keyed in a program and it ran perfectly
  • the keys are great!

The only glitch is that the results show the decimal point everywhere except the only place it belongs. Note that while I'm in process of typing a number, the decimal point behaves obediently:
[Image: uJFBZdB.jpeg]

But once I press Enter or any function, I get this "decimal-point-inversion" effect:
[Image: aWAr1uL.jpeg]
The number in the picture is, in fact, 5325.38.

While the effect has some entertaining value I'd prefer the more traditional way of displaying numbers. Has anyone seen anything like that? Any suggestion how it can be fixed?

Thanks in advance
Václav

PS: My first thread. I've been lurking around for a couple of months and I admire the knowledge and friendly atmosphere you share here!

RE: Decimal points on my HP-25 are plentiful! - Nigel (UK) - 09-05-2020 04:44 PM

This is the HP-25 low battery indication. Check the battery voltage and/or clean the contacts.

(Edit) By the way, congratulations on your purchase!

Nigel (UK)

RE: Decimal points on my HP-25 are plentiful! - vaklaff - 09-05-2020 05:21 PM

(09-05-2020 04:44 PM)Nigel (UK) Wrote:  This is the HP-25 low battery indication. Check the battery voltage and/or clean the contacts.
That was fast, thank you Nigel! Indeed, a fresh pair of AAs did the trick.

(09-05-2020 04:44 PM)Nigel (UK) Wrote:  (Edit) By the way, congratulations on your purchase!
Well, thanks again...

... and my last thank-you goes for not RTFM-ing me :-) Yeah, here's the related snippet from the manual:
[Image: ZOgBheB.jpg]
I should have done my homework first...

Václav

RE: Decimal points on my HP-25 are plentiful! - Steve Simpkin - 09-05-2020 07:39 PM

CongratulationsSmile My HP-25 was my first HP and is still working great (using alakaline batteries) 43 years later. Be careful cleaning the faceplate around the keys. The labels often dry with age and can be rubbed off easily.
You probably already know this but never use this calculator on the AC charger without a known good set of NiCad rechargeable batteries installed and clean battery contacts. Better yet never plug the AC charger into the calculator at all.