DOSBOx is an emulator of the PC/DOS platform that allows one to run DOS binaries (programs) compiled for x86 processors on the N900. Because it is emulating the platform, performance won't be terrific, but fortunately most DOS programs were written for slow computers.

There is a discussion of DOSBox on tmo:

An up-to-date DOSBox package is available in the maemo repository. After you install it, you'll probably want to edit the configuration file (found at ~/.dosbox/dosbox-0.74.conf) to do one or more of the following:

  • set up automount for a dos directory
    • You can use a directory in MyDocs for this (the bit that is mounted as N900 over USB mass storage). Create a new directory (dos_c for example) and copy your DOS program files into it.
    • Add these two lines to the end of the [autoexec] section of the configuration file to mount your dos directory inside the DOSBox and change to it:
 mount c ~/MyDocs/dos_c
  • enable the improved N900 keyboard map so that numbers can be entered
    • Download Javispedro's rover.sys file to the root of the DOS directory (dos_c following the above example)
    • Add this line to the end of the [autoexec] section:
 keyb rover.sys us

Now unmount the N900 drive and unplug the USB cable, and start DOSBox from the app menu. You can type the name of your DOS program just like you did back in the day.

Other possibly useful tweaks:

  • Enable the fullscreen mode in the configuration file.