Free42 for Android


I finished my Android port of Free42; the big missing features (program import & export and printing to files) are done. It's on my web site now.

Once I have tested it on a few real phones, I'll put it in the Android Market, too, but that may take another week or so.

- Thomas



That is FANTASTIC. Thank you very much. Let us know when it hits the market. :)



I second this - Fantastic work you have done.

Having file i/o now makes it the perfect calculator for my Droid X. Works great on Droid X.

One small suggestion - could you add a preference to turn off key clicks? Or better yet, toggle it to vibrate?

I'm now busy downloading RAW files to the phone.




Bill, your suggestion is noted. I can't say when I'll implement it, but in the meantime, you can make the key clicks go away by clearing flag 26. Of course that disables *all* sounds.



Thanks. The clicks are anoying during meetings.



A quick check on my Archos 70 is promising. The real estate for the keys is pure luxury. I'd like to see a hires skin, the image looks very "pixely".


I don't have any skins designed specifically for Androids yet, but you could try some of the other "mobile" skins (from the Pocket PC, PalmOS, or iPhone skins packages). The Android version stretches skins to fill the screen so you don't need an exact fit.


How do I install new skins? I managed to copy them to a local file. The filer isn't very helpful, it seems to hide most of the file system.


Put them in /sdcard/Free42. They will be picked up the next time Free42 is launched.


My /sdcard link is wrong, it points to /mnt/storage instead of /mnt/storage/sdcard. This must be a bug in the firmware. :(

Do you know of an ssh server so that I can administer my device better? I try rooting my device and correct the link but I don't know if that's permanent.


I'm afraid I'm an Android newbie myself -- I can't help you with advanced topics like rooting the device or setting up ssh.

You're not the first one I've heard from that said that the /sdcard path doesn't work; I think in the next release I'll add a field to the Preferences dialog to let you specify the skins directory yourself.


I suggest dropping /sdcard and using /mnt/storage/sdcard instead.

A custom option would be fine, too, for devices without an SD card. You should copy the skins to a local directory and update the files if a newer version is found in the configured directory. This way, you can add or update skins via the SD card without having to keep the card in the device. If the automatic update isn't feasible, a dialog "Import skins" would solve the problem.

Edited: 10 Apr 2011, 5:57 p.m. after one or more responses were posted


I doubt that that path works everywhere, either. I think full user-configurability is the only way to go here.


I've just edited my previous post.


ConnectBot can open a local console. I have it on my HTC Droid Incredible and it works like a charm.


I just posted it in Android Market. Just search for "Free42", or click this link.

N.B. This is my first time interacting with the Market; it was pretty painless, but in case anyone notices a problem, please let me know.

Also N.B. The app in the Market was signed with a different key than the ones I have been posting on my web site so far, so you will not be able to upgrade from the previous versions; this will be a new install and your persistent state from the previous install will not be preserved. You'll have to transfer your programs manually. I'll leave the version with the old signature on my web site for a while so you can upgrade to that first (in case you were using one of my alpha releases), export your programs, then uninstall and get the latest from the Market, then import your programs.

All future releases will be signed with this new key, both on the Market and on my web site, so this upgrade headache should not happen again in the future.

Edited: 10 Apr 2011, 3:30 p.m.



Thank you so much for the port of Free42. I installed it on my Motorola Droid (first gen) last night and look forward to using it. I did notice the "LCD display" is quite blurry on Droid. My screen is 854x480. Have other users mentioned this? Is there currently a way to sharpen the output?

Thanks again.

Edited: 11 Apr 2011, 9:30 a.m.


Hi Pal,

Free42 for Android stretches the skin to fit the screen, and the display is stretched along with it. If you're using a skin whose size is much smaller than the screen's, the end result is that both the skin and the display look blurry (*).

You say your phone has an 480x854 screen; compare that to the 320x480 screen that the built-in skin was designed for, and you can see the problem. Try using a larger skin, for example, one of the 640x920 skins designed for the iPhone/iPod "retina" displays; there are a few in the package. You have to copy the skins' *.gif and *.layout files to /sdcard/Free42, and Free42 will recognize them the next time it is launched.

Apart from the built-in skin, I currently don't have any skins that were specifically designed for Android screen sizes, but if/when I receive any, I'll put them up on my web site in an Android-specific package.

- Thomas

(*) I actually tried using graphics options to disable smoothing there, since scaling a blocky monochrome bitmap like the HP-42S display gives much better results without it... Unfortunately, it appears that some devices don't honor that option, and apply smoothing whether you want them or not.

I had the same problem with the iPhone version, interestingly enough, and had to resort to using a screen-resolution (UPDATE: I said "display-resolution" before, but that was wrong) off-screen bitmap for my buffering, since I just couldn't make scaling work the way I wanted it to. I may end up doing the same in the Android version at some point.

Edited: 11 Apr 2011, 8:11 p.m. after one or more responses were posted


Thank you for the quick response. I thought the LCD and the Skin might be drawn differently, so I did not think to try another skin yet. I will try it right away.

I may attempt to make an WVGA skin. I will report back if it is presentable..

Thanks again.

Update: Two of the iphone skins look excellent on my Droid (HofferthHiRes, Andy480x800), but the LCD is still slightly blurry, but usable.

Not complaining! Just saying..

Edited: 11 Apr 2011, 4:16 p.m.


Moin Pal,

on my Galaxy GT9000 (480x480) the jgoizueta_retina for the IPhone gives the best result.




You wrote:

to /sdcard/Free42

This originally confused me a little bit. I created a /sdcard directory and then a Free42 directory.

In reality, on a locked phone, the root is already at the /sdcard and I only needed to create the Free42 directory. The /sdcartd is hidden from the user.

This may not be true with all phones, but is what happens on a Droid X locked phone.




(Unix jargon alert!) The SD card is a separate filesystem which is mounted on /sdcard on most phones; on others, it may be mounted on some other mount point like /mnt/storage/sdcard, with a symbolic link from /sdcard to the actual mount point. Either way, when you connect the phone to your PC and select the "connect as disk" option, what gets mounted on the PC is only the SD card, and not the phone's entire filesystem hierarchy, so what you saw -- no /sdcard being in evidence, nor other directories you'd expect at the top level in a Unix system, like /etc -- is normal.

I suppose I should write a README file explaining all this. :-) Once I add an option in Preferences to let users select their own skins directory, I expect most of the confusion will take care of itself, since you can just browse the filesystem then and tell Free42 to use whichever directory you happen to have your skins in. That'll be in 1.4.68.

- Thomas

Edited: 11 Apr 2011, 7:29 p.m.



Understood. I'm an old unix hack from a long time ago. But it did take me a little thinking about it before I got it right. I'm guessing that most of us here are aware that Android is based on Unix/Linux, but there are probally a few people that just see the phone as it is and really don't think in terms of file systems.

Like you say, it'll all get clearer when you can browse the file system.

Since the real HP-42S is my favorite calculator, I'm having a blast with Free42S. Thanks again for all your hard work on it and for making it available.




My pleasure! And I will keep your feedback in mind -- Marcus' also -- I'll see what I can do about improving the skins business.

- Thomas


On my Archos 70 with Android 2.2, the symbolic link /sdcard is broken and cannot be fixed (root file system is read only). :( I'm waiting for the Thomas' update.


I'll add the skins directory location to Preferences and release a new version this weekend. Another user reported that the state file doesn't get saved, or not reliably anyway, on the Archos 43T, and the fix for that will also be in the next release.

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