HP-12c 'comma' variant (?brazil)

[AnnoyedOne]

(08-26-2024 09:49 PM)dm319 Wrote:  Yes, unfortunately the key image is not there.

Two things that old thread tells us (despite no photo).

• The "elongated % key" has been around since March 2011 -- some 13 years.
• China was the source of both the March 2011 and 2023 HP-12C's in question. In fact Jeff Kearns (in post #7) mentioned the poor built quality of the unit he'd purchased. That said it was bought (from Bureau en Gros) in Canada and not Brazil.
  

Perhaps the % key is old, but repurposed, stock.

No other (functional) issues are mentioned so...

A1

[AnnoyedOne]

Quote:HP 12C Calculator | Changing the Display from a Comma to a Decimal Point

https://hpofficesupply.com/wp-content/up...-Point.pdf

Want more? Use a internet search engine to find results for

Code:

hpofficesupply.com/wp-content/uploads 12c

A1

[dm319]

(08-27-2024 12:05 PM)AnnoyedOne Wrote:  [*] The "elongated % key" has been around since March 2011 -- some 13 years.

Maybe - but I'd like to see if the overall typeface is similar. There's something chunky about the n, i, FV, PMT, PV in the Brazil model - it's not just the % that is tall.

(08-27-2024 12:05 PM)AnnoyedOne Wrote:  That said it was bought (from Bureau en Gros) in Canada and not Brazil.

Yup - would make you think if it was being sold there at that time, we would see more in circulation?

(08-27-2024 12:05 PM)AnnoyedOne Wrote:  Perhaps the % key is old, but repurposed, stock.

I wonder, but the firmware is dated more recently.

(08-27-2024 12:05 PM)AnnoyedOne Wrote:  No other (functional) issues are mentioned so...

But he had it for less than a day! Bear in mind that superficially, you might not notice the differences. Puzzle 1 and 1b are very straight-forward solves, and the HP-12c 'comma' (as I've been calling it) returns exactly the same result for 1, and one extra digit for 1A. It in fact beats the regular HP-12c for puzzle 2, returning a result as accurate as the HP-12c platinum.

It's only when you push the device with edge-case TVM problems, or by the sounds of it, specific NPV/IRR (I'm not in finance and I don't really understand what that calculates) or try to change the radix that you would encounter the error.

[dm319]

(08-27-2024 04:54 PM)AnnoyedOne Wrote:  

Code:

hpofficesupply.com/wp-content/uploads 12c

If I can get hold of one I'll give it a go! (but as mentioned before, the original redditor said they could change it on another HP-12c so presumably knew how to).

[Gene]

I have reached out to the individual responsible for HP calculators about these 12c units in Brazil.

They encourage anyone with such a unit to return it to the store where it was purchased.

Gene

[Gene]

Additional information from the top for these units in Brazil:

1) Most of the defective units were captured and have been reworked with the corrected firmware. However, there may be some still in the channel since some of the distributors were unwilling to return the units for rework.

2) Confirm if the bug is present. If the bug is not evident, then the unit is almost certainly an updated version. For the next several months, all three types of units (Defective (a few), updated (many), and those with the “Made in the Philippines” marking) will be in stores, so confirming the bug is key to avoiding unnecessary returns.

2) Support units (replacements) have been shipped to Brazil to aid in any support phone calls the Call Center may receive. These units are marked “Made in the Philippines” on the box which should be an indicator they have the correct firmware. Customers with issues should be encouraged to contact the Calculator Support team at: +55 (35) 2106 9101 // 0800 727 0678

[AnnoyedOne]

(08-28-2024 08:16 PM)Gene Wrote:  1) Most of the defective units were captured and have been reworked with the corrected firmware.

Would that be

Code:


CHE--d1d1h
2015-01-30
C 2008 hP

per

https://www.hpmuseum.org/forum/thread-22157.html

If so where did

Code:

CHE--3198h
2023-03-19
C 2008 HP

come from?

[dm319]

Wow.

So in the end these are official HP-12c units.

Gene, do you know the backstory with the firmware?

I wouldn't use the term 'bug' for this. This is a variant.

A bug implies this is an error or fault introduced to otherwise regular HP-12c firmware. I suspect this firmware may use none of the code from the regular HP-12c.

(08-28-2024 08:26 PM)AnnoyedOne Wrote:  If so where did

Code:

CHE--3198h
2023-03-19
C 2008 HP

come from?

This is the key question! Who wrote it? Why did they write it given the regular firmware is available to both HP and the public? How did it get past testing?

Why?!

The biggest issue is that there are now HP-12c units in circulation that break the 'de-facto' standard in financial TVM calculations.

[dm319]

Prof Kahan brought us the TVM problem 'a penny for your thoughts' (number 3 in my little collection). If you saved a penny every second for a whole year, with an interest rate of 10%, how much would you have saved after one year?

It's a particularly hard one to solve because the large 'N' means you have a periodic interest rate of 3.171e-7. This means in the TVM formula where we have 2 lots of (1+i)^-N, we are adding 1 to a very small number and losing information because of the truncated representation of 1.0000003170979...

The original HP-80 had an accuracy of only 1.2 digits, returning 312925.0203, and the HP-70 didn't improve on this.

The next (and cheaper) models HP-22 and HP-27 managed a huge improvement in this calculation going up to 9 digits of accuracy, and I believe this was partly due to Prof Kahan's involvement. I assume the improvements related to writing explicit algorithms allowing e(x)+1 and ln(1+x) to maintain accuracy.

The HP-12c comma returns an accuracy of 7.2 digits (331666.9849). Better than the HP-70, but worse than the HP-22, putting it at around 1974 in terms of performance.

The HP-12c improved on the HP-22/27 achieving 10.6 digits of accuracy, and the HP-12c platinum took it one step further, getting to 12.2 digits.

[AnnoyedOne]

I just saw this "new in package" HP-12C on eBay. Note the elongated % key and weird font X<->Y one.

   

A1

PS: I'm not willing to buy this (US$50) and suck the firmware (fake or not). That said I have saved the eBay link in case someone does.

[dm319]

That's a good spot A1!

Certainly the same '%' symbol, but still has 'Hewlett Packard' on the bezel. I guess it's anyone's guess what firmware it has.

[AnnoyedOne]

(09-05-2024 10:16 AM)dm319 Wrote:  That's a good spot A1!

As much as I'd like to claim "eagles eyes" the truth is that I was curious about the listing for other reasons.

One listing photo does show a serial number (on the package) and it is Chinese in origin. I don't recall the year but not recent. Still the keys are "interesting".

No idea if I could even extract the firmware even if I bought the item.

A1

PS: The serial number is 4CY4520D3D.

[Didier Lachieze]

For info about HP 12C keyboards % key differences, this was reported in this post in 2011 and was linked to different factories in China.
The original link in the post above can be found through Archive.org here.