[Asus Padfone X and S] baedamichi@gmx.de:
Hi folks,

I own a Padfone S, and the thing which bothered me about it when I got it was that it (like every KitKat device) uses MTP protocol for transfer of files to PC instead of USB mass storage (UMS), which in my opinion is a really good thing with regard to the phone's internal storage, but which was a really bad decision by google with regard to external SD cards.

It took me a really long time of googling and trying things I found on the internet until I finally found something that works for me, so I thought maybe I write my solution down here for others to find. All the apps I could find on XDA developers for that purpose didn't work for me, probably because they were written for different phones (what I could find here were apps for Sony, Samsung and LG devices).

What you need:

a rooted Padfone S (probably works on X as well)

an app called "USBMounter_v1.1_Panda"

For your convenience, I have attached the app. Now, what's funny about this app is that I couldn't find any reference to it on any of the sites written in a language I understand (English, German and a bit of French), I just happened to find this app while googling by accident, seems to be written by some Chinese or Taiwanese guy. I thought this was noteworthy, as of course I can't tell you anything about the app's origin, reputation or license, since I don't understand a word of what's written on any of the sites which have this file, but since it's publicly available on so many mirror sites, I think it's okay to share it with you. But keep in mind, use at your own risk (I personally didn't see any signs of malicious behaviour).

How to make it work:

install app

unmount your external SD card

enable USB debugging

open app, and set switch to UMS

connect your device to PC

You will see your SD card in your Windows explorer as a drive with a drive letter, just the way it used to be with every Android device in the good old days.

Now, it is VERY important that you unmount your SD card from your device BEFORE using it with your computer! If you forget that, the SD card will still appear in your Windows PC's Explorer, and at first file operations seem to be carried out normally, but you'll soon end up with inconsistencies in your file system! Sort of makes sense anyway, two devices accessing a file system at the same time doesn't seem to be a good idea.

Unfortunately, I still haven't found a working widget to mount/unmount my SD card, so I always have to go to the settings screen to do that. I tried the "Switch Pro" widget from the Playstore, which supposedly has a mount/unmount functionality, but that doesn't work with the Padfone S, when I tap the relevant button, nothing at all happens. So if anyone knows of a solution to mount/unmount SD card with a shortcut, feel free to post it here.

Finally, two more pieces of information:

My Padfone is on the latest stock rom (UL-ASUS_T00N-WW-11.10.7.18-user), the only changes I have made to my phone is rooting (of course), and chaning the recovery to ClockworkMod.

My SD card is a 128GB MicroSDXC, formatted in NTFS. The Padfone is able to handle this SD card, both size and NTFS file system do not cause any problems at all.

Well, I hope my post can help a few people who want to make the most of the Padfone's SD card slot. ^^

Have a nice day!