cdmackay wrote: ↑Thu Oct 03, 2019 5:53 pm
One way to look at it would be that the DM42 and DM41X are intended to be modern versions of existing calculators, namely the HP-42S, and HP-41CX. So choosing between those two is really a choice based on those existing RPN machines, both of which are extensively documented.
Yep. The DM41X is really aimed at 41 fans specifically. While it shares the DM42 hardware, it's actually not using the fancy screen to its full potential in order to more closely appeal to fans of the original 41. Lots of people are decades-long 41 fans. If you are not one, one of the other calculators would probably be a better choice. Unless of course, there are any of the many 41 modules that you want to use directly. That might be another reason favoring it. I would not expect the DM41X to be cheaper (certainly not much so) than the DM42—the hardware and labour going into it are the same.
The WP-34S (and forthcoming WP-43) are not based on a single existing calculator, but are an attempt to design a new system from scratch, taking the best features from a range of HP calculators.
Indeed. The 34S and 43S are calculators designed by RPN calculator geeks for RPN calculator geeks. The original HP-41C series and HP-42S were broader market, certainly for engineers and scientists, but not necessarily true aficionados. The developers of the 34S and 43S go beyond what HP would have dared do for a broad-market product.
The 34S is a firmware upgrade (and keyboard overlay) for two real HP calcs, the financial 20b and 30b, neither of which are still made.
I think I'd call it more a complete rewrite, not just an upgrade. It's completely new RPN scientific calc firmware stuffed into what was intended to be an algebraic-entry business calculator. It's got gobs of features (the original poster mentioned buying a DM16L -- the 34S supports all the 16's integer math functionality REALLY well) and a user interface packed full of clever stuff than HP wouldn't want to get into for the high-volume 41C series or 42S.
The upgrade is done using an almost impossible to find cable, or by asking someone who has the cable to do it for you, once you've sourced an existing used 20b/30b (the latter apparently has a far better keyboard).
You certainly do not need to use the official hard-to-find-and-expensive cable! It's simple to use a generic USB-TTL serial cable. Mine cost $3.99 from Newegg with free postage. Two 1 kΩ resistors are also used which I had on hand... maybe a couple pennies each. No soldering even. Without the special connector on the "official" cable, the homemade one does take a steady hand and maybe a couple of tries, but it flashes fine. I've done it this way many times.
If you want to do the optional crystal mod for clock functions, it's a couple of dollars and 15 minutes with a soldering iron if you have a steady hand. If not, you can skip it.
The forthcoming 43S will be an updated version of the 34S, running in the SwissMicros DM42 chassis, as will the DM41X.
I think the ambition for the 43S goes well beyond putting the 34S into a new chassis. I'll let the creators address that though.
SUMMARY:
•The WP-34S is a pretty cheap root to a super-zippy calculator with new-in-box HP30b donor calcs selling for <$50 on the US eBay. Sticker sheet is another S5 or $6 I think. It's a wee bit DIY, but not too bad.
•If you don't have the bit of "tinker time" needed for the 34S AND have the funds, the DM42 is great. If you've already used the HP42S and know/like it, then it's especially a no-brainer, as it is a "clone +".
•I'm very excited about the DM41X, but that is because I am a 41 fan. If I were not, I'd probably go with the DM42.
•The forthcoming 43S is quite a ways from fruition. It would probably be my personal choice IF it were available today. But it's not, so it's not an option now... more for the future wish list in a couple years.
Anyhow, we are very lucky to have such interesting niche products available to us! How nice it is that we even have choices!