Hello,

Recently I noticed that used panasonic toughbook CF-18 are offered for couple of hundred euro's. It is a 2006 model, discontinued and with outdated specs of course. Still I wonder if an old toughbook could be useful for Pd work. I am foreseeing open air events, workshops with kids, etc. It would be so cool to bring a ragged-rugged computer to an event, make it play beautiful music and invite everyone to just join in without worries about your hardware vs their fanta's and beers.

Pd audio dsp is not too demanding on processing power. My setups usually take some 20-25% CPU time on my 2GHz macbook. The CF-18 has a 900MHz centrino which is a pentium mobile processor, and expandable 512 MB ram. Does anyone happen to use this computer (or one with similar specs) for Pd? How does it compare to recent laptops?

Katja

Hi Katja:
Even though I did not use that CF-18 computer, I bought a Toshiba T115-S1100 which came with win 7 starter or home "super limited". Anything was crawling instead of running on that thing. I "bulldozered" the entire HD and installed Debian Squeeze. Firstly, I ran Pd-exended with a regular real-time kernel. I had a standard 5% CPU usage in Jack audio server and htop (processes manager) showed some 10% to 20% of CPU usage due to Pd-extended.
Then I gathered some courage and compiled a real time kernel just for the laptop and it was day against night. Ok, maybe against twilight, but now jack uses 0.2% - 0.5% CPU resources and Pd-extended runs smoothly with an average of %5 to 9% when doing some tweaks with a patch based on Miller's phase-vocoder example.
Therefore, if it is to show Pd / Pd-extended, I recommend Debian Squeeze (or the latest testing distro) with a especially-tuned real-time kernel.
I hope this helps you as much as your posts and externals (and tutorials, of course!) do help me.
Best regards,

Sumidero

Hey Sumidero, that's a very good recommendation indeed. Compiling your own real time kernel sounds like hocus pocus to me. You have been so brave to undertake this operation, can you tell something about it? What type of information do you need about your computer to tune a real time kernel to it? Did you find a good howto? I've heard favourable comments on Debian before, like running 16 channels of audio in Ardour on a netbook. This seems to be the ultimate way to make small computers useful for Pd.

Further internet search learned me a bit more about the cf-18 toughbook which is widely offered second-hand. Regarding the screen two types are produced: resistive touchscreen and electromagnetic digitizer. The resistive touchscreen would be most useful for live performance in my view. Unfortunately the digitizer seems to be the popular one. The biggest bummer is it's memory type: DDR PC 2100. Even in it's days, this must have been a slow computer, built for endless workdays with simple tasks.

Performance-wise, toughbook cf-74 would be a better choice. This one is not so cute, cannot be converted to tablet. It is also less tough, a 'semi-rugged'. Most of them have a resistive touchscreen. Specs of the older ones are comparable to the earlier MacBooks: 1.8 - 2 GHz Intel core (2) duo, up to 2 GB DDR2 RAM. Well this is a candidate for Pd live performance stuff. They're offered at 400 - 600 euro/dollar.

Katja

Yes, please share some info about compiling and tuning the real time kernels - even with my haphazardly put together real time setup I experience much better performance (like your first experience sumidero) but it seems that I need to take some action to resolve my ATI fglrx driver issue.

Katja, "PD DSP is not too demanding on CPU" Yeah! If you know what you're doing! CPU demands increase quite a bit with synthesis and filtering.

There are lots of good wikis about the real time but many of them are out of date system specific guides.

I noticed a forum yesterday recommending http://tangostudio.tuxfamily.org/en

Anyone heard of it?

Hello Katja, PonZo:
I will soon post the log of compiling an rt kernel for debian. There are also a couple of tweaks to do to have better performance. I have to translate all that to English before posting. I am glad that you found this useful. Read you soon, mates!

Sumidero

Hello @Katja, @PonZo:
I posted the promised log in this new thread:

http://puredata.hurleur.com/sujet-5605-compile-install-real-time-kernel-debian

Best regards,

Sumidero

So I picked a used CF-74 toughbook indeed (for 350 euros) and installed a basic Debian. After a couple days of tweaking and fiddling, everything works. Touchscreen, audio, external monitor... a complete all-in-one system for live performance and presentations. A hardware dream fulfilled!

I still have to compile a realtime kernel for this computer, but even without that Pd runs smooth with one of my setups, SliceJockey. Some 35% CPU load, no glitches, no distortion, with the built-in SigmaTel STAC9200 sound chip. Plenty of CPU headroom to perform other tasks simultaneously without influencing sound output. This computer has 2 GB of DDR2 ram and a 1.8 GHz Intel Core Duo on board. Not today's specs for a laptop, ok, but it's not totally outdated either.

About the 13" screen. This has rather low resolution of 1024*768 pixels. It is bright enough and has wide viewing angle. The resistive touch panel blurs the pixels somewhat, so it does not give a sharp view. Because of the (old-fashioned) resistive technology, the touch screen must be operated with stylus or fingernails, not fingertip. It feels a bit weird to drag an object with a fingernail, this really requires some practice. On the other hand, this screen (with matte finish) does not get intransparent with a layer of greasy fingerprints. It is single-touch.

For my Pd purposes, this is (at the moment) the best hardware system available, even when some aspects are not so modern. It has the connectivity, interfacing and storage of new and old computers combined: ethernet, vga, cardbus, serial port, modem, audio in & out, built-in stereo speakers, USB, sdcard-reader, hard drive, optical drive, bluetooth, wifi, touchpad, keyboard, touchscreen. This is a real tool, a machine yeah

Katja

Hi Katja:
Congratulations! I wish one day I will cross the world to Europe and attend to one of your performances.
By the way, you may try installing a real time kernel. Look for it typing in a console, superuser mode:

# aptitude search kernel

Suppose you find "linux-image-2.6.31-9-rt " amongst the list. Then try installing it with:

# aptitude install linux-image-2.6.31-9-rt

Reboot. If you get kernel panic (the computer may not boot completely and only leave the caps lock led flashing) reboot and choose the previous kernel you were using. In that case you may want to compile a rt-kernel "ad-hoc".
You can uninstall the panicking kernel using:

# aptitude purge linux-image-2.6.31-9-rt

Good coding! Best regards,

Sumidero

Thanks for the hint, Sumidero. With command $ sudo apt-cache search linux-image I got an extensive list of Linux-images, but no realtime kernel. Never mind, I was already prepared to compile one for the computer, encouraged by your documentation. That's for coming weekend. I'll report progress in your dedicated thread on realtime kernel compilation.

Regarding audio stuff with Debian, I forgot to mention this: the base install came without PulseAudio. I only noticed this when Pd-extended would not start because command 'pasuspender' was not found.This command is apparently called from Pd's startup script, and with good reason (assuming the PulseAudio plague has already infected your system). With command 'pdextended' Pd can still be started. Because Pd could not sync the audio stream (and neither could Jack) I have been confused about it during a couple of days. Should I install PulseAudio, only to disable it with 'pasuspender'? Fortunately I resisted. It turned out that it was a matter of ALSA mixer settings. There are too many mixer tools (amixer, alsamixer, alsamixergui, alsa gnome mixer). With all unnecessary channels disabled, Pd and Jack could finally sync in full duplex.

About the CF-74 I also forgot to mention one detail. Some are offered very cheap (200 euros) but actually these are models without touch screen.

Katja

edit: after listening to the sound a bit more, I conclude that the built-in SigmaTel chip does a fairly good job with a simple electret mic. No hiss, no hum, just clean sound. After reading all the complaints about SigmaTel, this is a nice surprise.

you have to be carefull with those realtime kernel i did use them a while and i have experienced compatibility issues with graphics card drivers for example... i have experienced some other compatitibillity issues which i have forgotten wich one they exactly where

i am currently using the normal ubuntu 12.04 lts installation not ubuntu studio with rt kernel and it is working fine. i cant tell any diffrents between the rt kernel and the normal one, tough jackd is configured for rt threads and i work itb only on an lenovo x121e with i3