Actually, the last games from the days of DOS didnt need more than a 150 mhz CPU to run, a Pentium Pro or Pentium MMX. Anything over 200 might actually be TOO FAST to run most of the older DOS games. (Unless you mess with that SLOMO proggie, which still doesn't help everything.)
There are a couple ways to get old games to run on new systems.
Since I am a serious game geek, Ill list the basics:
1: Emulation. This one is kind of obvious though. There are programs out there to make your modern PC think its an old computer, or even an arcade machine! From Trash 80s to Commodore 64s to those crap Sinclair Spectrums you UK folk seemed to adore, all the way up to Playstation One! The faster your PC, the better most of these programs will work. Many of them, like ePSXe, CCS64, and Zsnes are BETTER than running your old games on their native system! From 3d graphics improvement on your PS1 games, to Save States and pixel smoothing on your SNES to Warp speed modes on the C64, it makes all your old favorites seem like whole new games in some cases! Virtually every old bit of hardware has been emulated, and many of these programs will run your own legitimate games, especially the CD ROM based ones! Its the only way I ever managed to complete Terminator for the Sega CD, a game that took 2 hours to beat, but had no save locations OR continues. And I usually died in the last level or two of the game! There is also an emulator called DOSBOX that runs old DOS games, but its mostly the early 386 and older games. It really can't do later games than that right now, both due to the speed of the emulator, and the protected mode programs of the later era being a bit more complicated.
Some choice programs in this category are:
Dosbox (DOS PC programs up to circa 1991-92)
Zsnes (Super Nintendo/Super Famicom)
MAME (Almost every arcade game ever made)
VICE (Commodore 64/128)
Magic Engine (Turbografx 16/PC Engine.)
WinUAE (Amiga Computers. Generally Amiga vets only though)
ePSXe (Playstation 1. )
FCE Ultra (NES/Famicom)
2: Windows 9x compatibility mode in XP. I still use 98 just to keep with my old games. The only thing 98 doesnt run these days is those pay for money music downloads services like Napster and iTunes. Their loss, and I prefer MP3s anyhow. Many games with some twiddling will work this way, and you should be able to drop to DOS and run some batch files to play your older titles. Some DOS proggies will run under 9X anyhow, and there is a program to slow down DOS proggies in Windows as well, which is handy for those old games that never had a framerate limiter put in.
3: Dual/Multiboot systems: I forget how to do it, but its supposedly pretty easy to set up your PC to dual boot to Linux, Win 98, Win XP, or DOS. With a couple programs to set up your USB devices to run under DOS, and MOSLO to slow some of the old programs down, you should be ok.
4: Retrogame collections: This is more common on the consoles than the PC (since PC users all prefer the usually free and more accurate if not so easy to use emulators like I mentioned above), but there are plenty of packs FULL of old classic games made to run on your modern systems. Some games have sound and speed issues, but its legitimate and not piracy, and most collections are sub 20 dollar US prices. The problem is most liscensed games or obscure titles never get this treatment for the most part, and they keep adding 2 or 3 games to newer releases of older Retrogame collections, like the current Midway Arcade Treasures, which is just 2 or 3 older collections with a handful of new games ported to the modern aged systems. Its still nice and legal, even if just to buy then go play an emulated version of the same game. For you horror fans (well thats what we are here for, right?), things aren't quite so rosy. Not too many horror games are on these sorts of collections. Still, if we support these projects, more will come..
5: Remakes/Fan Upgrades: Like my post above, people are updating the engines of old classic games to run shiney and pretty on modern systems. Some are professional remixes ala the Gamecube Resident Evil remake, but most are free or super cheap fan made programs. For horror folks this area seems to be your best bet, thanks to ID Software giving away the source code to their older games to let fans keep their old stuff alive. Though all the ID Game upgrades require the original games to play. (No big for me, as I own every core ID game up to Quake 2. ) There are also many games inspired by the old favorites with fans making their own sequels or clear "me too!" versions of them. From Doom, to all of Sierra and Lucasarts' adventure games and so forth, a little looking around the Net can garner you some great stuff. Im STILL finding things that blow my mind. Sourceforge.net is a great storehouse of fanprojects of this sort, not to mention computerized versions of your favorite tabletop games too..
6: Ebay. If you have a little money to burn and risk, you can find pretty much any old game for sale, and the hardware to run it on. At a price. And the potential for the things to NOT WORK, or require a little TLC to bring back up to spec. It can be fun and addictive though. The videogame version of buying and fixing old junker cars if you will. Just look out that you don't find a few hundred other things you want too!
Ok.. that ought to help folks on their path towards old game enlightenment. I didn't put any links down since I figure most of you know how to use Google, and the search and discovery is half the fun..
