Closest thing to a 42S-II


Hello all.

In one edition of SOLVE, there is a mention of a 42S redesign. It would be nice to see HP re-introduce the 42S with even an SD Card update. In the interim, what would be the next best thing to a next gen 42S?


Good question. Personally, I'd be tempted simply to add the SD card for storage and bump the speed with a modern CPU and recompiled software as per the near-mythical (will we ever be able to buy it?) 39GII.

I'd resist the temptation to add a larger display or graphing capabilities. Of course that would doom the calc commercially...I think. I wonder what the sales figures are for the new 15C?


Jose Gonzales on his blog at mentions that he has now received his final batch of HP-15C LE and that production has now stopped. Based on the serial numbers he speculates that the total production run is 25000 - not bad for such an "old" machine!

Nigel (UK)


A WP42S? ;)


A WP42S would be an option. But as a Macintosh PowerBook G4 user running OS/X 10.4.11, Samba and PC and serial port specifics needed to maintain the next project from the 34S family-a 42, the 42S may not be an option.

Any suggestions on how I'd be able to update and maintain the 34S with a Macintosh PowerBook G4 running OS/X 10.4.11?

Any other thoughts on a next gen HP-42S?

Edited: 26 June 2012, 1:02 p.m.


There won't be any ;-)

There may be a WP 43S but that depends on the HW guys first :-)


Okay. This 43S sounds intriguing. For whatever you can reveal, what would its function set, programming capabilities be?


Matt, 43S is little more than a label so far. There isn't any written spec yet as we are still busy with the WP 34S. But it's SW will certainly be based on our experience gained here, while its HW is not existent yet. I can imagine a WP 43S might feature, in random order:

  • An LCD allowing for softkeys as well as displaying a complex number in a single line simultaneously (so it shall allow for showing two lines of alphanumeric data at least);
  • Different data types (integer, real, complex, string, matrix), named variables like in HP-42S;
  • Pocketability like the Pioneers;
  • A quality keyboard featuring slanted rotate-and-click keys which register always (the big ENTER goes without saying);
  • RPN for operation and keystroke programming like in WP 34S;
  • A choice of four or eight stack levels like in WP 34S;
  • I/O capabilities at least like in WP 34S, using USB or SD;
  • Stacked menues like in HP-42S, including a user menu.
This list is not complete yet. And other people's MMV :-)


There are a few random ideas out there already.

I'd be aiming for unlimited stack, not just four or eight levels.

- Pauli


Those random ideas may be just exactly the right mix!


oh, and I thoght the 43S was just the german translation of the 34S :-)

seriously now, we're all eagerly waiting on it!


We too :-)


Richard Ottosen and I are working on suitable hardware. We have an SD card working. The hardware also has a USB port, but we haven't got that working yet.



I am curious about the difficulty involved in getting an SD card working. Which kind of FAT do you support? Did you start with any kind of available code for dealing with the FAT, or start from scratch with the specs? What kind of effort is involved?

I have toyed with the idea of adding SD card support to the 41CL (the hardware is there) but after reviewing the specs, I think that I am not enough of a software guy to tackle such a task.

Thanks, Monte


I use open source FAT filesystem code called FatFs, which is written in C. It comes with sample code that can talk to the SD card in MMC (1-bit serial) mode.


I used FatFS on my "sound effects box" project. It has lots of compiler options to include features you need and exclude features you don't. I was using a Freescale micro with 32kB flash and 2kB RAM to basically play MP3s off the card, and I didn't need to save anything to the card. So I was able to go read-only (which reduces the code immensely!), and unbuffered (reducing the RAM footprint to under 600 bytes). And I still had FAT32 support, so I can use a 32GB SDHC card! I think the latest version of FatFS even has long filename support...

Basically you just need to provide a few low-level I/O routines: read a block, write a block, card status (card detect, write protect detect, etc.), that sort of stuff. The standard SPI interface (synchronous serial with read data, write data, clock and chip select) works with every SD card I've tried, even though support of the SPI interface is "optional" in the SDCard standard.

You can also use FatFS with IDE (P-ATA) and CompactFlash cards just as easily -- only the six low-level I/O routines really change.

I'll be happy to provide my ugly (but functional, and reasonably documented) source (for Freescale MC9S08QE32) in C if anyone needs it. (I tend to brute-force code stuff, rather than do fancy interrupts and callbacks and all that fancy stuff!.) I have the init, block read and card status stuff. (Didn't write a block write routine -- not required for read-only compile option...) Just mail me via the forum. Especially willing to trade if you have documented code for USB mass storage device or human interface device on MCF51JM128!



Richard Ottosen and I are working on suitable hardware. We have an SD card working. The hardware also has a USB port, but we haven't got that working yet.

I would see the biggest problem in designing a proper keyboard (and getting it made). Have you got a solution for that?

If I can help with the hardware design in any way, please let me know :)



Okay. It'll be fascinating to see the finished product.

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