Psychtoolbox released

Psychtoolbox 3.0.18 Beta update "Experimental Taylor expansion " SP7 was released at 7th August 2022. As usual, the complete development history can be found in our GitHub repository. The release tag is “”, with the full tree and commit logs under the URL:

This release only contains improvements for the RaspberryPi computer. The 3.0.18 series may be the last version supporting Raspbian OS 10, given that the current stable version providded by the RaspberryPi Foundation is OS 11 / Debian 11 “Bullseye” since quite a while now, and the maintenance costs are too high to support two OS releases in parallel.


  • Installer: Compatibility fixes for Linux RaspberryPi OS 11 aka Debian 11 / Bullseye on the RaspberryPi microcomputer. Make installation more smooth.

  • Screen: Fix pageflipping on the RPi 4/400 with VideoCore-6 gpu again after it got broken again for Debian 11 by new half-assed format+modifier dmabuf optimization attempts. PsychLinuxConfiguration now installs a special mesa config file with special secret opt-in parameter that enables special downstream patches made to Mesa v3d to fix the half-assery. This way, pageflipping and visual stimulation timing/timestamping works again on RPi4/400 after upgrading to RPi OS 11.

  • PsychPortAudio: Fix selection of default sound output device on the RPi 400. Allows ‘sysdefault’ as a viable choice of device.


Hi Mario, do you plan to migrate to the 64bit version of RPi 11 or stick to the 32bit version? At least for other things, the 64bit version seemed to give a bit of a performance boost…

Sticking to 32 bit for now, so my and others RPi 2B continues to work - that one is a 32 Bit ARM cpu, so wouldn’t work with a 64-Bit OS. And this one OS upgrade 10 → 11 and the troubleshooting thoroughly killed a weekend, so I’m not keen on repeating that anytime soon.

I don’t have a clue how many labs are actually using our RPi support. So far I only know of about 2-3 labs for sure, so it is barely justifiable to support/maintain it at all.

And probably nobody pays for the maintenance with support memberships anyway, just like basically nobody pays us for anything, a disappointing situation that will lead to drastic measures pretty soon if the attitude of our users doesn’t change.

But then I spent at least 2 months of my “spare time” improving the Linux graphics drivers and kernel myself to make the RPi a good solution for labs with need for a cheap small computer, lots of digital i/o, and modest graphics/sound requirements, so I don’t like my work going to waste. At the same time, the RPi people are tweaking graphics/display all the time to squeeze out better performance and this was the 2nd time in two years they totally broke visual stimulation timing in absurd ways, once on OS 10 - fixed properly in the OS thanks to myself since ~ February 2021, and now on OS 11, fixed by a workaround in PTB since yesterday, because i can’t spend time on a proper fix for something that may only be used by 0-3 labs and that nobody pays for supporting.