Product Review: Siemens' SIMpad SL4

If it looks like a duck and it quacks like a duck, then the SIMpad is a tablet PC.
Real Life Tests

To get started, download the serload application and an image from, connect the SIMpad to your PC using the serial cable and start the 20 minute upgrade process. I had to do that twice, because the first flash with the cpk1sp1 image failed--a bad start.

When it finally succeeded, I was greeted with OPIE boot screen. But bad news again: OPIE 0.9.1 is buggy. You first have to change the default theme to get title bar buttons. At that very moment, for no reason, OPIE crashed and I had to reboot the SIMpad--a very bad start indeed.

The lack of jffs2 support on the SIMpad is a real problem for now. It means you cannot install applications besides those on the image. Every Zaurus 5500 .ipk application should be supported, but because the filesystem is not rewritable, nothing can be installed. jffs2 journalized and rewritable filesystem support should come soon, with OPIE 0.9.3 (used in OpenZaurus 3.2) support, to fix this #1 drawback. This improvement also would let the Eur. 199 Sinus Pad support a Linux flash. I also was disappointed when I noticed my Intel Wi-Fi card was not supported; it works on a GNU/Linux desktop machine with a pcmcia-cs patch.

Now the good news: you can find and use the traditional OPIE tools and the Konqueror browser. PCMCIA works, the USB slave port works and a pre-alpha smart card driver exists, but there's not yet such a driver for the Windows CE SIMpad. Moreover, a SIMpad with the ck1sp1 OPIE image was shown at CeBit this year, where a very active German community is working on Linux support.

Currently, the SIMpad has no sound support for OPIE. If you prefer TinyX over OPIE, however, sound should work. I could not manage to play or record sound, a problem I attribute to my lack of knowledge of the SIMpad hardware and the current state of the project. I intend to spend more time on it to at least get fullscreen video playback with mplayer and a correct hardware support for jffs2, the sound abilities and PCMCIA. It should not be impossible as the SL4 uses the same hardware as the Zaurus 5500.

Daily Usage

Given these limitations, one may wonder what can be done with a SIMpad under Linux/OPIE besides establishing the classical PIM? The big screen makes it perfect to read documents, far better than a Palm or a Zaurus. The instant-on feature also is convenient; the SIMpad can be started and stopped in a couple of seconds. This feature comes in handy when you want to use the SIMpad for short durations, say between two subway stations, when the boot and suspend process otherwise would eat most of the time.

I find that reading documents is becoming a more and more central part of my PDA usage. For example, my research work currently requires reading a lot of publications. Most of them are in PDF format, and qpdf display them on the SIMpad. I don't think I could bear the eye strain caused by reading these tiny prints on a Zaurus screen.

Likewise, I do not enjoy the smell of newspapers and I do not have enough time to read them on-line--but I cannot live without the NY Times. My solution? Plucker creates a .pdb archive for off-line reading with opie-reader. I previously did that on the Zaurus tiny screen, but now that I have the big and comfortable 800x600 SIMpad screen I don't want to go back.

The seven hours of battery life also helps make the SIMpad an excellent device for on-line browsing, well, as soon as my Intel 2011 Wi-Fi card is supported.

I hope video support and sound support will evolve to let me use my SIMpad as a portable media center, so I can encode DVDs to a PCMCIA removable hard drive and then watch them on the SIMpad. If I can do this currently on a CompactFlash on my Zaurus, it certainly will be possible to do on SIMpad's identical hardware.

Get One

In spite of all the problems I encountered while trying to run Linux on the SIMpad, this is a very promising device. Now that I have one, I don't want to be without it, if only for the big screen perfectly suited for reading. The SIMpad currently is being pulled from the market and therefore is selling at only a fraction of the original price. I strongly advise anyone with good Linux knowledge and a will to hack to get one. NRG Systems still have some, but not for long. Finding a dealer with SIMpad in stock is going to become harder and harder.

While the SIMpad may not be as consumer friendly as the Zaurus because of some important features currently missing, these problems should be fixed soon, as new OPIE images are released. Then, you can show your neighbors who spent $3,000 for an XP Tablet PC your Eur. 300 Linux tablet PC.



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problem to start working with SIMPAD SL4

mehrdad Khansary Atigh's picture

Dear Sirs,
I have purchased simpad sl4 recently and have problem to calibrate its display.I perform the instructions according to operation manual of simpad sl4 but after calibration the message of " please press Enter to save calibration" appears, but no keyboard menu or Enter can be found on the display.So kindly help me how I can calibrate it.

By the way , please inform me how I can connect a flash memory to the simpad sl4 .there is not installed any port on it.

I will be waiting for your prompt reply.

Best Regards
Mehrdad Khansari Atigh

Re: Product Review: Siemans' SIMpad SL4

Anonymous's picture

Nothing strange at all. OpenSIMpad [] brings new life to the device!

Michael Lauer
OpenSIMpad core developer

Re: Product Review: Siemans' SIMpad SL4

Anonymous's picture

Fantastic! After reading this article I recalled that Swisscom, a major ISP & phone company here in Switzerland, had briefly carried the Simpad in their retail stores. Killing time I walked into one yesterday to enquire about it, expecting the answer to be, "what are you talking about?". To my surprise the store had two units in the back that were returned and apparently Siemens didn't want them back. They reluctantly sold it to me for 300 CHF (230.749 USD). Wow, if you guys do not own one you are missing out. Most of the problems the artice above highlighted have been addressed. I use it for on the road PHP Dev and surfing at home. Thing is surprisingly fast for 206 mhz and the screen is bright and perky. If anyone would like to have one drop me an email at and I'll see what I can do for you. Linux rules!

Re: Product Review: Siemans' SIMpad SL4

Anonymous's picture

You can buy this SIMpad SL4 at:
One of the Siemens Dealers in the Netherlands

Re: Product Review: Siemans' SIMpad SL4

Anonymous's picture

This product is End-Of-Life, so it's a bit strange that the review
is appearing on this site....

Siemens Dealership
The Netherlands