HP Forums
NP-41 Emulator (may be) - Printable Version

+- HP Forums (https://www.hpmuseum.org/forum)
+-- Forum: Not HP Calculators (/forum-7.html)
+--- Forum: Not quite HP Calculators - but related (/forum-8.html)
+--- Thread: NP-41 Emulator (may be) (/thread-4537.html)

Pages: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

RE: NP-41 Emulator (may be) - smp - 03-17-2018 03:18 PM

Are there any more of these available for purchase, or was there only one run?
I sent a PM long ago, but never received a reply.


RE: NP-41 Emulator (may be) - rprosperi - 03-17-2018 03:34 PM

(03-17-2018 03:18 PM)smp Wrote:  Are there any more of these available for purchase, or was there only one run?
I sent a PM long ago, but never received a reply.


Chris is working out the issues with a new board design, but each iteration takes many weeks (board fab time in China, then slow boat delivery, then lots of long-term testing (days/weeks)) but has suggested that when the definitive design is reached, he likely will offer more units for sale, but doesn't want to sell any further units until then. The good news is he is making progress. Smile

RE: NP-41 Emulator (may be) - smp - 03-17-2018 11:35 PM

(03-17-2018 03:34 PM)rprosperi Wrote:  <...snip...>... The good news is he is making progress. Smile

Yes! Indeed, that is good news. I'll be patient. Smile


RE: NP-41 Emulator (may be) - Chris Chung - 03-20-2018 11:35 AM

(03-17-2018 01:54 PM)Massimo Gnerucci Wrote:  Alas Chris, I think I finally bricked it.
This morning I started upgrading a DM42, then a 39GS with newRPL and, finally my NP-41. The first two went well, but not the third.

Well, too many different procedures to follow for an aged brain, it seems...

After connecting the unit to the PC via USB and Teraterm I uploaded the new firmware (or I think I did), now all I have on the display is "NP41 =2432" no matter what key combination I try.

Let me know, please, if there's something I can try, otherwise I'll wait for a new board revision and order it, if/when available.

Keep up the good work!
Massimo, the recurring display of NP41 = xxxx means your unit is stuck at startup (reading the battery voltage). It may also be resetting itself if the XXXX voltage value changes intermittently.

If the key test fails, i.e. key press does not show key value, there is a chance that the key scanning lines got shorted, although this is not likely. However, this could also prohibit you to enter bootloader mode when / if the key scan H/W fails.

Another possibility is that the battery had drained too much and the unit cannot continue further when certain peripherals are required (like FRAM access need certain voltage). You may try a fresh battery but it may not solve the problem totally. When battery drained like that fast, that means problem w/ the H/W or PCB. I had some units assembled and runs well, and put in sleep (turn off), they would act up after some hours / days and take 10+mA, resets itself etc. The normal operating current for a good unit is about 1.2mA (1.5mA when doing key test) and 0.6uA during sleep.

The bootloader should still be working. You may want to try to re-do the firmware update and see if it can be unbricked.

Otherwise you will have to wait again. Smile

+rprosperi, +smp

I am still working on the final design, working on the last 10% of traces, plue the key legend silkscreen. The old S/W I used only goes to 8 mils traces. I am using a better S/W that can do 6 mils traces. Not sure the trace width had caused all these intermittent problem, but got to try anyway.

RE: NP-41 Emulator (may be) - anetzer - 02-18-2019 07:29 PM

(03-20-2018 11:35 AM)Chris Chung Wrote:  I am still working on the final design


Are there any news on this project?

Thank you!


RE: NP-41 Emulator (may be) - hmilz - 01-20-2021 06:11 PM

Hi everyone - this thread has been silent for a while, which hopefully does not mean the project is stale.

As I wrote here , I have been working on a HP-41 like clone for some weeks but I would like to explore using nonpareil and the original HP-41 code. Chris must have converted the multithreaded Gtk nonpareil to a static library that can be used in an embedded environment. Does anyone know if the ever published the source code for this (which, indeed, he should have given that nonpareil is GPL'd ;-) ) .

Thank you!