A question from elsewhere, copied here since it is a question with a good answer I think:
Using the latest (v40) C43 program, I noticed that Undo and CLR are reversed (Undo works with g, rather than f as it should, and CLR menu is accessed with f).
On my Mac simulator and on my DM42 the keys work correctly. Unless there is a bug in the Windows Simulator which I cannot test on my Mac, the answer probably lies in the following discrepancy:
The reason is probably because we distribute two key layouts, you will notice the 'L2' in the DM42 firmware file, i.e. C43_40L2.zip.
L2 is the version made for native DM42 key compatibility.
L1 currently is on the simulator only, and is also our ‘preferred’ layout which is getting onto our metal C43 key template. There on L1, UNDO is on f, because we believe it is more useful to have the UNDO on the easy single press key. When our key template is available, we will make available both L1 and L2 versions for the DM42.
L2 is the more DM42 compatible layout, i.e. the C43 aligns with the DM42 existing yellow labels so that you do not need a template. The DM42 has CLEAR on the yellow label, therefore C43 uses CLEAR to call the CLR menu, and Undo must sit on g. That is reversed from L1.
We did spend and inordinate amount of time on this group a year ago to really find the optimum key layouts and I think the L1 layout is a real gem.
Interesting fact 1: you can change the keys around. Go the g to the KEYS menu, and choose either DM42 to use L2, or C43 to use L1. This swap works on either simulator or hardware.
Interesting fact 2: you can even select WP43S too, which will line the keys up with the main project's hardware calculators for when they will be available.
This looks nice if you change it around on the simulator, because the labels follow the selection in real time.
Escape clause: If you do play around with the KEYS too much, you can always reset your User mode keys by using g[KEYS] RESET on FN6, which will restore the User mode keys.