## DM41X vs DM42 vs WP-34S...

General discussion about calculators, SwissMicros or otherwise
Coyotte
Posts: 7
Joined: Sat Sep 28, 2019 3:59 pm
Location: Liège (BE)

### DM41X vs DM42 vs WP-34S...

Hi All,

I recently subscribed to this forum.
I just bought a DM16L wich should be on his way to my letterbox to help me in my day-to-day application developper tasks.

Discovering the HP alike world, I wonder if could not extend my RPN use to other general purpose domains. (I always have a calc on my desk)

Too new to this kind of calculators, I do not have the experience needed to find out wich calc I should buy later and why choose one rather than another.

For what I know at present time :

Pros for DM42
- Quite Huge memory
- Large screen
- Best precision (but not really a requirement for my use)
- PC connection
Cons :
Price (I do not mean it's not wothing the price but it's a not negligible amount of euro)

Pros for DM41X
- Better display than DM41L (same as DM42 ?)
- Quite huge memory
- Seems to be a HP-41CV++
Cons :
Price ? (Will the price be around the DM42 ?)

Pros for WP-34S
- Price lower than DM42
- Programmable memory huge enough for usual calculations
- Lot of built in constants as also lot of scientific and financial functions.
Cons
- Less capabilities ?
- Screen smaller than the two others

So, or a general purpose user, what are, for you, the pros and cons of those options ?
Do you have experience to share (not regarding DM41X I presume )

(I understand that this can be looked as a religious question and I do not want to start a trolling topic )

Coyotte
cdmackay
Posts: 162
Joined: Fri Oct 05, 2018 8:33 pm
Location: Cambridge, UK
Contact:

### Re: DM41X vs DM42 vs WP-34S...

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.

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.

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. 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). There are a few people selling pre-converted models on eBay, but not cheaply. The USB PC connection is an expensive extra hardware mod (via the pre-converted route) (as are the IR & timer options), as neither of the 20b/30b had that.

The forthcoming 43S will be an updated version of the 34S, running in the SwissMicros DM42 chassis, as will the DM41X.

As to choice; it's difficult. Many of us already have the DM42 and WP-34S, as well as an existing 41 option (a real one, a 41CL, or the SM 41L), and will also be getting the DM41X and DM43
Cambridge, UK
41CL/DM41X 12/15C/16C DM15/16 71B 17B/BII/bII+ 28S 42S/DM42 32SII 48GX 50g 35s 30b/WP34S Prime G2
& Casios, Rockwell 18R
burkhard
Posts: 19
Joined: Fri Mar 16, 2018 10:15 pm

### Re: DM41X vs DM42 vs WP-34S...

cdmackay wrote:
Thu Oct 03, 2019 7:53 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!
cdmackay
Posts: 162
Joined: Fri Oct 05, 2018 8:33 pm
Location: Cambridge, UK
Contact:

### Re: DM41X vs DM42 vs WP-34S...

good points burkhard, thanks.
burkhard wrote:
Thu Oct 03, 2019 10:16 pm
I think I'd call it more a complete rewrite, not just an upgrade.
sorry, that's not what I meant. I agree, and I'd already said "design a new system from scratch". Here, I simply meant that the 34S isn't a hardware product, but a new firmware that is applied to an existing HP calc, using the latter's firmware upgrade method.
I think the ambition for the 43S goes well beyond putting the 34S into a new chassis.
right but, again, that wasn't what I meant, which was merely that the 43S would be different from the 34S, in that it's going into a dedicated chassis, rather than a previous-model donor like the 34S.

Thanks for correcting me on the cable! I'd forgotten all about that. And for the excellent summary, which I'd neglected

cheers!
Cambridge, UK
41CL/DM41X 12/15C/16C DM15/16 71B 17B/BII/bII+ 28S 42S/DM42 32SII 48GX 50g 35s 30b/WP34S Prime G2
& Casios, Rockwell 18R
Coyotte
Posts: 7
Joined: Sat Sep 28, 2019 3:59 pm
Location: Liège (BE)

### Re: DM41X vs DM42 vs WP-34S...

Dear All,

If I understrand what written between de lines, the choice lives more in the buying order than in the models

(By the time, I've received my DM16L and I'm impressed by the efficiency minded organisation.)

Have a nice day,

Coyotte
WigglePig
Posts: 9
Joined: Fri Jul 26, 2019 2:12 pm

### Re: DM41X vs DM42 vs WP-34S...

If you're anything like me then you'll eventually buy them all!

I stumbled across SwissMicros a while back, before they used the SwissMicros name, when I was looking for a used hp15c. I ended up buying a DM15 and had been very impressed with the superb customer support after I managed to crack the display on it!
I now have the DM41L (and a mended DM15) which is superb but I still find myself wanting a DM42.

In short, I would recommend saving up some money and ordering all of them!

Jason
Coyotte
Posts: 7
Joined: Sat Sep 28, 2019 3:59 pm
Location: Liège (BE)

### Re: DM41X vs DM42 vs WP-34S...

Thanks Jason.
This is also the conclusion I came to

Coyotte