DMDX Help.


    Last Updated : 04/11/24 j.c.f.

    This is the help for DMDX version 6 (current version number is here), Dmastr for Win32 (Windows 7, 8, 8.1, 10 and 11) with DirectX 9.0 or later.  DMDX is a Win32-based display system used in psychological, linguistic and other laboratories around the world to measure reaction times to visual and auditory stimuli.  It was programmed by Jonathan C. Forster at the University of Arizona and continues to be maintained by him.  Version 1 worked on 486 class machines, Version 2 of DMDX dropped support for 486 class machines allowing much more accurate timing and generally cleaned up a lot of stuff like multi-monitor support.   Version 3 cut support for Windows 95, radically restructured the Audio Input and introduced the DMDX installer and .CHM help files.  Version 4 added Unicode support and addressed the long standing trouble DMDX had with other applications stealing it's focus.  In addition version 4 also introduced Auto Mode that allows DMDX to operate without the use of TimeDX (all but essential for remote testing), 4.2 expanded the support for millisecond (as opposed to tick) display durations and 4.3 introduced variable length macro names making their use much more readable.  Version 5 added a Direct3D rendering path that is required for Windows 8 and later operating systems as DirectDraw (the original rendering API) is now emulated.  Version 5 also dispenses with operating systems earlier than Windows XP.  Version 5.1 added support for NVidia 3D shutter glasses, 5.2 added support for AMD FreeSync and NVidia G-Sync displays allowing DMDX to have a variable retrace rate and arbitrary display durations not tied to the raster interval and 5.3 significantly tightened up DMDX's parsing of keyword parameters and added an Introduction button that runs a built in item file introducing DMDX's features and exposes some test modes so one doesn't need an item file to quickly test if a machine is going to run DMDX at all well (it wasn't fully blocked out for about another 18 months and still receives periodic updates, it's text is included here).  Version 6 dispenses with support for Windows XP (and Vista I suspect but who ever used that?) with the addition of support for Windows Touch touch screen devices and version 6.1 adds support for eye trackers such as those made by Gazepoint and other devices controlled over a TCP/IP connection.  Version 6.2 added global support for non-Roman character sets in file names using UTF-8, be it in item file names or in resource file names and 6.3 added support for named counters in addition to the classic numbered ones matching the variable length macro names from 4.3, 6.4 adds support for Unicode in counter and macro names (including emoticons!) and to cap it all off 6.5 adds in place macros when a back tick ` is used for a lead in instead of a tilde so they don't have to be defined before the item they're used in.


Please note that we distribute this software as is, with no guarantees as to its reliability. It may not be redistributed for sale.

The DMASTR software is distributed free of charge, and we ask only that you acknowledge use of the system in publications (e.g., "The experiment was run using the DMASTR software (DMDX) developed at Monash University and at the University of Arizona by K.I.Forster and J.C.Forster.").  You can also cite our DMDX paper: DMDX: A Windows display program with millisecond accuracy. Forster, K.I. & Forster, J.C. Behavior Research Methods, Instruments, & Computers (2003) 35: 116.

Although the software has been in constant use for more than 20 years, it is constantly evolving, and hence there is always the possibility that new releases may contain bugs. We do not assume any legal responsibility for the software, but we do assume the responsibility of advising you as rapidly as possible of any bugs that we do detect. For this reason, it is important that you get your name onto the user list serv if you plan to use the system on a regular basis.  To do so:

  1. Send a message to from the address you want to subscribe to the list.
  2. In the subject line of your message, type in: subscribe dmdx Firstname Name (replace 'Firstname Name' by your own first name and name).

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