So today I was one of at least two people trying to help Jerry Pournelle get the original Railroad Tycoon running under Windows XP. The secret is DOSBox, a cross-platform DOS emulator.

DOSBox emulates a 386-class PC, with VGA and a SoundBlaster, under multiple operating systems--most notably, Linux and Win32. It's pretty slick in a number of ways. Boot it up, and you've instantly got sound configured and 637K of conventional memory available, along with enough extended memory to round out 16 megs. All without messing around with arcane and archaic memory manager commands in config.sys. (Remember that?)

When Jerry last e-mailed me, the game was running but he was having difficulty getting the mouse to work, even when hitting ctrl-f10 to lock the mouse. I suspect it's easier to get PS/2 mice to work with the emulator than USB mice, as under Windows USB is a different driver. But I'm not certain. I'm still trying to find my box of old DOS games so I can even test the emulator properly. Based on his site, it looks like he got it working, but didn't elaborate on what it took. I don't blame him--if I'd just gotten the original Railroad Tycoon running again, I think I'd have better things to do than write back a dozen people to say, "It works."

Because DOSBox actually emulates everything and doesn't rely on the hardware, you need a GHz-plus machine to get 486 speed out of it. That's the price you pay for higher compatibility. The cardinal rule of emulation has always been that any machine can perfectly emulate any other machine as long as speed is not a factor. Fortunately, those aren't especially rare or expensive these days.

I'm definitely going to keep looking for that box of old floppies. My 1.3 GHz Athlon ought to run that old DOS stuff pretty well, I would think. I've been wishing for about six or seven years that something like this would come along. Long enough that I wasn't even ready for it when it appeared in a reasonably mature state...