DMDX Help.


    Last Updated:  01/17/17 j.c.f.

    This is the help for DMDX version 5, Dmastr for Win32 (Windows XP, Vista, 7, 8, 8.1 and 10) with DirectX 9.0 or later.  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.  Version 5 adds 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.


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. doi:10.3758/BF03195503.

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).

    Once your subscription is confirmed posts can be made to Please don't send attachments to the list. Your subscription should also be manageable by pointing your browser at