Please can you beta-test this unusual Free42 skin

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Oct 25, 2023, 9:07:51 PM10/25/23
to Free42 & Plus42
For the last 3 months I've been working hard on a new skin for Free42 (which also works with Plus42 if you want the bigger screen). As you'll see below, the skin is quite complex so the chances of bugs are much higher than usual. Skins usually aren't updated on Thomas's website, and people typically don't go looking for skin updates even if they do exist, hence my request/plea for a broader audience to shake it down before release.

My motivations for making this skin included:
- My field of electronics engineering (and many other fields too) ubiquitously uses metric notation (e.g. 1.2GΩ, 3.4nH, 5.6µs, 7.8pF, 9.0 TB) so I wanted a faster way to input such numbers.
- I thought the original calculator keyboard layout wasn't great. So sick of pressing shift at the bottom and then going to the top for the most common functions, or pressing STO/RCL at the top and then going to the bottom for a number etc.
- I never liked losing the functionality of the top row of buttons if screen menu buttons were showing.
- I never liked the screen menu buttons not being aligned with the top row buttons.
- I'm constantly using physical constants and properties, but the 42S only offers π (and I detested it being a shifted key).
- I found many of the skins too hard to read (OK, so I'm old).
- I found some the desktop versions too small, the hot-keys too confusing and saw many other opportunities to improve it.
- There were several basic functions I frequently used that I wanted to add to the keyboard vs the CUSTOM menu.
- I was sick of accidentally pressing the decimal point as I swiped up from the bottom to switch apps in iOS.

The documentation files are somewhat graphical so they're jpeg files. The first (Mueck_Skin.jpg) covers the skin's button layout - you should start there. The second (Mueck_KeyMap.jpg) is only for the desktop version and covers the hot-keys and bonus functions not available on the phone version. This is also the first skin requiring a compulsory program - CONST, a user-customizable program for physical constants and properties. Both the desktop skin and the CONST program use capabilities unavailable in the current version of Free42/Plus42, so you MUST use the latest beta for the desktop version:
The phone version of Free42/Plus42 doesn't have a beta, so I "hacked" its CONST so that it's still 99% functional (it's just missing a minor feature). It is a different program to the one in the desktop zip files so don't mix them up. I'd be interested in your thoughts on the default constants provided in the CONST program (provided in both text and raw formats). The 1st menu level shows 6 basic constants you'd use in high school, the next level up caters more for electronics engineering, and the final 3rd level is just crazy specific - mostly to indicate that it's obvious you'd want to be tailoring it for your own needs at that point. I haven't included documentation on how to extend CONST for more or less menu levels, although comments in the text version are pretty clear. I'll be the first to admit that the mathematical symbols for some of the constants on the screen menus look ugly - you have to do the best you can with the character set provided...

Regarding the skin's layout, I really sweated all the details for button arrangements, animations & spacings, and also fonts, colors, screen menu alignments... I'd be very interested your feedback on the visuals and usability etc. A lot of work also went into the desktop version's hot-keys. Between the main keyboard and numeric pad layouts for macOS, Windows and Linux there are about a thousand hot-key definitions in the layout file! I've validated 1/3 of them (i.e. all the Mac ones) but I don't have a Windows or Linux machine so I'd really appreciate some help there (and please don't forget the numeric pad if you have one!). In fact, if your keyboard has a numeric pad then that's the very best place to perform your basic calculations without dealing with what you'll read about in the KeyMap jpeg (you'll know it when you read it).

All current desktop skins try their best to maintain a correspondence between the keyboard keys and the calculator buttons. For example, if you've selected "1" on the keyboard as the hotkey for the calculator's "1" button then ⇧1 on the keyboard (i.e. "!") should yield "ASSIGN" just like ⇧1 on the calculator does. That's all good in theory, however all existing skins do poorly in that key/button correspondence for reasons you'll read about in the KeyMap jpeg. Additionally, many awkward keyboard assignments arise because many calculator function names share the same first letter. In the end there are way too many complications and remembering everything is (in my opinion) just too hard. My goal was a FULLY consistent hot-key set i.e. if a hot-key was chosen for a Standard Key Mapping (shown on the skin) then the shifted version of that hot-key will always match the corresponding shifted version of the calculator button. That goal was achieved by implementing a modifier key rule and a using a couple unconventional key mappings for which you may have a bad first impression, but it does simplify things. I'm intentionally keeping things vague to entice you to look further at the KeyMap jpeg :-). If you do have a numeric pad then all then all of those sacrifices made in the name of consistency can be nicely avoided.

When using this Free42 skin in Plus42 (for the larger display) you'll notice an unnecessary default header line at the top of the display. You can turn it off by via DISP and navigating till you find HDR. I also usually have 6 rows showing (also within the DISP menus via ROW+ and ROW-) for both the phone and desktop apps. If you're using the desktop beta version you can also turn on the display of LASTx via DISP and navigating to LTOP :-).

Aside from the 2 documentation jpegs, I'm attaching a phone skin zip (, and two desktop skins ( and the larger sized Given that Plus42's DESKTOP version is free you'll definitely want that instead of Free42's - it'll also make you want to buy the phone version of Plus42 right away like I did ;-).

So that's about it. Even if you don't want to do any testing I'd really appreciate just looking over the two jpeg files and let me know your thoughts. Happy testing :-). 


Oct 28, 2023, 3:53:31 PM10/28/23
to Free42 & Plus42
I have the next version - it includes a relayout for the EXIT key to the top right and several desktop app hot-key corrections (most notably for the shifted metric notation keys).

Some focus areas include:

1. Confirmation of as many Windows and Linux hot-keys as you can manage - I'm unable to do that and it's where I expect the most issues.
2. Desktop app hot-key choices - I'm happy to entertain changes.
3. Desktop app bonus functions available via hot-keys (including other possible functions I could add for you).
4. Keyboard layout rearrangements. I'm mostly good with the buttons themselves, but some of the shifted functions could be moved around.
5. The operation and usefulness of the CONST program (including any hassles installing it)
6. Are the default constants on the first menu level the most appealing for a general audience?

Looking forward to your thoughts and comments.
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