JoyDriv - A TSR to provide INT 15h support for joysticks

Many machines either do not implement, or implement only partially the BIOS
INT 15h interface for joystick support.  This TSR remedies this situtation.

It is smart enough to not install itself more than once, so you can use it
in a batch file.  It does not support being removed, but that shouldn't be
too hard to implement.
