HP-10bII+ hardware

[Mark]

Hello,

I recently purchased a 10bII+ calculator, simply because its color scheme is identical to the 48S/SX and the 32SII which I really like. Second reason is that there are enough scientific functions for a daily use -I'm not a financial guy. ...and the 3rd reason is that I wanted to have some fun.

Well, it was a good surprise to me : The machine is light but looks robust, the keyboard tactile feel is good to me even if it doesn't match the 20th-century HPs -a bit too much noisy maybe. And the display quality is really good, much like the Voyager series.

From a software side, it appears (please correct me if I'm wrong), based on quick tests I've done, that the arithmetic base code of the Saturn series is used, and emulated presumably on an ARM SoC as is done in the 20b/30b.

I was curious to see exactly what's inside, and I saw 2 screws between the batteries compartment and the JTAG connector... but it's not that simple. The calculator halves remain firmly tied, and I don't want to deteriorate my machine.

So, is there someone who could tell me if the SoC used in this machine is the AT91SAM7L128 found in the HP20b / 30b ? To be honest it's only technical curiosity ; currently I don't have any special project in mind.

Many thanks in advance,
Marc

[Didier Lachieze]

You'll find some answers in this thread starting with post #9.

[Gene]

The key to the 10bII+ was squeezing in all those scientific, statistical and new financial functions:

trigs
hyperbolics
permulations and combinations
Normal and Students t distributions and inverses
lots of regression models including best fit
bonds
breakeven
depreciation
date arithmetic

without breaking any previously existing 10bII functionality.

Amazing job, IMO.

If only it had RPN. :-)

[Mark]

To Didier :

Thank you ! What was I thinking about, to forget doing a search on the old forum...

To Gene :

I'm absolutely not a financial expert, but I do second you saying it's a good job. True, if only it had RPN... but even without that, I think it's a nice little machine.

...and by the way, speaking about RPN : my 10bII+ is on the table besides the 65C02-based homebrew SBC which I'm working on, to create a desktop scientific RPN calculator -but that's another story... and much fun for sure.

Once again, thank you !
Regards,
Marc

[Katie Wasserman]

(02-19-2015 07:07 PM)Mark Wrote:  I was curious to see exactly what's inside, and I saw 2 screws between the batteries compartment and the JTAG connector... but it's not that simple. The calculator halves remain firmly tied, and I don't want to deteriorate my machine.

So, is there someone who could tell me if the SoC used in this machine is the AT91SAM7L128 found in the HP20b / 30b ? To be honest it's only technical curiosity ; currently I don't have any special project in mind.

Others have mostly answered your questions about processor and functionality but not how to get inside (if you're still curious).

Remove the 2 screws in the battery compartment then take a very thin, strong plastic or metal tool and run it around the seam between the two halfs. I use a metal guitar pick. There are 4 catches on the right side that have to be released, 4 on the left side, two on the top and one on the bottom. Each is about 1 cm long which is why it's such tight fit. It just snaps back together of course.

If this puppy had RPN it would be favorite calculator as it has all the functionality I need for everything I do (programming aside).

[Mark]

Thank you very much, Katie !

Your description matches what I was supposing. I didn't tell the whole story, please forgive me :

Being a collector, I opened many calculators. The most risky was, 20 years ago, my first HP48SX : it survived, with only a few (and very small) dents, an opening done without applying the current recommended method. I simply pried it open, very slowly... Putting it back was really difficult as you guess. I suppose I was very lucky ! It still goes strong and I take much care about it.

By the way, what kept me from opening my 10bII+ is that I'm afraid about the plastics being more brittle than the "good old ones". I don't have (yet) any spare machine, and years passing by make myself more cautious :-)

Regards,
Marc

[MarkHaysHarris777]

(02-19-2015 11:33 PM)Katie Wasserman Wrote:  . . . then take a very thin, strong plastic or metal tool and run it around the seam between the two halfs. I use a metal guitar pick.

Katie,
This is a great tip! I have been using an old modified credit card (too soft, too thin) with limited success. The guitar pick (I use a little thicker one) works great. Thanks!