C43 is now C47
C43 is now C47

C43 changes to C47. The information on this web site remains partially applicable and for now remains in place. 47calc.com is the new home. C47).

The C43 is the modern RPN hand-held calculator in the spirit of the 32S, 32Sii & 42S.

The C43 started out with dissatisfaction that the most ambitious and unusual hand held calculator project ever, the WP 43S was following a path to a hybrid key layout; something between an old and a new.

The WP 43S arithmetic operator key layout is neither relating to modern HP layout, nor to the older  HP layouts. It is a brand new layout, with top to bottom order of the arithmetic operators in the in the style of the HP32SII, HP42S and HP48G, while the location of these buttons is on the left hand side of the calculator in the style of the old HP67 and HP25.

The C43 was born as a fork of the GPL3 open source WP 43S project, named in the style of HP28S/C changing the letter S in WP 43S to WP 43C.

C43 (Classic43)    layout is inspired by the late Pioneers, i.e. the HP27, 32SII and 42S.

C43 is not a upgraded HP42S or upgraded Free42. It is a fully fledged WP 43S with familiarity on the user interface where possible.

The bezel in pre-production is a beautifully designed metal key plate, printed in full colour. Photos of the prototype will be published here.

The discussion here, currently, is on the first phase only, which is making available the bezel for Do-It-Yourself installation on your existing DM42, either:

  - Replace your DM42 stock bezel plate permanently, or

  - Mount the bezel plate on top of your existing DM42 bezel plate temporarily

Plate details: A steel faceplate, 0,?? mm thick is being made in Canada, and will be shipped world-wide. The plate can permanently replace the existing DM42 plate, or could be temporarily attached to the DM42 keyboard with thin double-sided sticky tape.

DM42 keys: The DM42 key labels need not be changed.

Plate installation: Detailed instructions will be published here.

C43 bezel in pre-production:
C43 Prototype bezel, mounted on a DM42:


First version of the metal keyplate


   Watch this space for photos of the prototype bezel plate

          ( Bezel plate is in pre-production, 

               no final product as yet )
Sneak preview !