Swiss 15C "Clone" has arrived


The initial batch of the Swiss HP-15C “clone” is being received. This machine has been discussed on this forum several times. The photo shows the series of HP-15C’s to date with the Swiss clone being the fourth in a series. Oops. This site doesn't allow photos without a URL. sorry.

Here is my initial reaction.

1. Measured Specifications
Size: Credit card: 2.249 x 3.381 x 0.302 inches.(HWD) - stack of ten credit cards.
Weight: 50.6 gr. (1.79 oz.).

2. Construction
Robust using a rigid frame. Back held by four Phillips screws. Simple three piece assembly – Front,
Back, Internal frame. See video on Michael’s website:

3. Battery
Single CR2032 coin cell. requires a #0 Philips screw driver to replace. Installing a new batter will produce PR ERROR in the display.

4. Keys
Small, true metal dome similar to the original HP-15C. Keyboard colors identical to original HP-15C. The strong tactile feedback is not “in sync” with the key contact and it is possible to press a key and feel it “click” and not make contact. This appears to be in the design because it seems to apply to all keys. I have normal sized fingers with a lowered sense of “feel” so I simply press a bit harder. To address this issue I cut the erasure end off a pencil to use to press the keys. This “tool” fits nicely into the edge end of the soft case that comes with the calculator. The keyboard notations are clear and about as large as possible which is great for the visually impaired, i.e. over 40 years of age.

5. Display
The display may be compare with the HP versions and Michael elected to use upper case for the error messages, etc. This makes it even easier to read. The test display shown in the photo was produced when turning the calculator on while holding the multiply key down. RUNNING will flash four times first.

6. I/O Connector
An I/O connector is in the front edge. it is not a USB “B” connector but should not be difficult to find – according to Michael.

7. Speed
Not as fast as the 15C LE but quite close.

Conclusion. This is a very nice always-with-you high end scientific calculator that will provide 95% of all scientific calculations you will need to make. Its small size allows it to fit nicely (with my Sony DSC-TX1 camera) in my shirt pocket.

X < > Y,



Hi Richard,

I am glad you received the 15C clone. Your review is encouraging, so I look forward to receiving mine early March!



Mine came today too. It's amazing how small it is compared to a real 15C.

Some of the keys are incredibly difficult to press (I have to get a firm grip on the calculator and squeeze very hard for it to register), so I will probably be taking it apart this weekend to see if I can adjust anything to make it work better.

Overall I am impressed by it. The screen is very nice. The re-creation of the rear label is a nice touch. The faceplate looks very professional, with the raised keys in the (Mylar?) overlay.



Richard, the USB connector is a Mini B USB connector. It's deprecated so it probably should not have been used, but there are countless supplies of cables for it. It's the same type used on the 50g, so if you have a 50g you can just reuse the cable from it.

It was probably selected because it's easier to solder onto a board than the Micro USB ports favored today.



Mine arrived today as well. Neat little bugger. A lot less obvious you are nerdy as it can be concealed very easily.

My only initial concern is the whether or not the edges of the PCB board will wear over time and get damaged. I wonder if we could come up with a low profile black anodized frame. On to the CAD!


The lower left corner is not completely flushed/closed.

The top of the 3 layers comes up away from the lower two layers, causing it to "bounce" up and down when I click a key in that area. It also caused a memory loss at least once.

The screw is all the way screwed in, so that does not appear to be what is wrong.

VERY fun little machine, but I will have to figure something out about it not being totally closed.


Gene; There are people here who would use that kind of problem as a welcome excuse to take it apart and play with it. After reading your post; i think you're one of them.


So who is going to have a try re-purposing this device?

The CPU is a bit light on memory but is plenty fast enough. I don't know for sure yet, but I have been lead to believe that there is an unpopulated eight pin SOIC pad in there that can accept an AT45DB041B serial flash device.

Small size, nice form factor, fast CPU, good display, ....

- Pauli

Possibly Related Threads…
Thread Author Replies Views Last Post
  Swiss Micros calcs Mike Powell 6 2,393 10-26-2013, 05:03 PM
Last Post: Mike Powell
  TI-BAII plus clone (with emulator) fhub 3 1,894 06-04-2013, 07:49 AM
Last Post: Mike (Stgt)
  WP34S ver 3,2 Arrived from Eric Namir 0 952 04-16-2013, 03:30 PM
Last Post: Namir
  DM 15CC silver edition arrived! Hans Holzach 10 3,246 12-05-2012, 01:40 AM
Last Post: Juergen Keller
  Swiss clones of the HP Voyager series WaltMaken 10 2,830 11-30-2012, 11:40 AM
Last Post: Harald
  DM-15cc arrived Ethan Conner 25 6,513 08-18-2012, 02:55 AM
Last Post: aurelio
  The Blue HP 50g has arrived. Eddie W. Shore 48 11,901 08-05-2012, 02:55 PM
Last Post: Eddie W. Shore
  DM calcs arrived, but... David Ramsey 4 1,877 08-04-2012, 12:42 PM
Last Post: Michael de Estrada
  DM-16cc arrived Lincoln R. 0 961 07-12-2012, 12:04 AM
Last Post: Lincoln R.
  HP 71B arrived Harald 17 4,614 05-22-2012, 02:39 AM
Last Post: Bruce Larrabee

Forum Jump: