cogadh: I'd be a little concerned about the D-pad. Even if it is a DOS game that only expects a couple of buttons like older joysticks, it likely also expects analog direction control, not digital.
Miaghstir: Many older joysticks were digital, no?
Mostly those that used Atari VCS/2600-style sticks, like the C64 and Amiga. They may have had a few analog sticks, but most of them were digital, with microswitches representing the directions rather than a pair of potentiometers. (Fine for most games, but I don't see flight sims being very bearable with a microswitch stick...)
PC joysticks were predominantly analog, though there may have been a few digital ones here and there. (Old ADB Mac sticks were probably mostly analog too, but I'm far from certain on that one.)
Oh, and to further add confusion, the analog/digital distinction applies to input devices in two ways-the direction controls AND the interface. 1990s joysticks started having a digital gameport interface (one that does NOT work with your typical cheap gameport-to-USB adapter, which only works with the old analog gameport interface), but with analog axes for the main joystick movement for precision's sake, of course.