Lots of old programs won’t work on my XP operating system. I was wondering… I’ve seen emulators for old video game systems like Nintendo. Are there emulators for old computers, like the IBM XT? Are they legal? Could I use them to play old games like “Swords of Glass” and “King’s Quest”?
-FrL-
In theory, this is exactly what XP does when you try to run a 16 bit application; it runs a program called NTVDM (Virtual Dos Machine) that is an emulation of a 16 bit processor and other stuff, then runs your 16 bit program within that emulation.
Problem is that a lot of older software achieved perfomance increases by directly addressing hardware, which XP doesn’t allow (in XP, the software is expected to address the Hardware Abstraction Layer, which in turn talks to the hardware - this way, any improper hardware requests are simply ignored, rather than executed, possibly crashing the machine), so in practice a lot of older software, particularly games, simply won’t work on XP.
Use VMware! It creates a virtual computer inside your computer. You choose things like how much memory and disk space the virtual machine is going to have. Then you can load any OS you like.
You will still need a version of DOS to install. I think since DOS is quite old copyrights might have expired and you can download it for free.
I don’t think MS-DOS is free yet. You can however download DR-DOS or FREE-DOS.
I feel nostalgic from time to time, and use dosbox to play old games. King’s Quest, Space Quest, Eye of the Beholder and so on works like a charm.
I have Win95 on an old Compaq Presario (either 166 or 266mHz) for old games but there are some that don’t even work on that. I’m definately going to give DOSBox a try for those.
I’ll recommend Microsoft VirtualPC. Works well on the Mac anyway, and I don’t think they’ve discontinued the Windows version.
If you’re specifically interested in running the old Sierra adventure games, you don’t even need an emulator. King’s Quest, Space Quest, and the like were written in a high level format called “AGI”, and run with an AGI interpreter. While that made it easy for Sierra to port games to several platforms (Apple II, Mac, DOS, Amiga, etc.), it also lets modern programmers write their own interpreters so you can run these games- natively- on Windows, Linux, or the modern MacOS.
Two AGI interpreters you might want to try out are Sarien and NAGI.
You can download a boot-disk for an older version of DOS from bootdisk.com.
I always keep a DOS 6 bootdisk around for when I want to play Sam & Max Hit The Road or Red Baron, or any of the other stale old games that still give me joy. (I’ve lost one of the floppies for Space Quest III, dammit!) I used it a lot more before they came out with the Windows versions of* X-Wing* and Tie-Fighter, though.
(Microsoft has left www.bootdisk.com unmolested for the seven years it’s been around, so I’m guessing that means they’re comfortable with it.)
Do a search on DOSBox, it is one of the simplest DOS Emulators out there. IIRC it simulates a 486 machine. I’ve used it to play some c. 1995 games that simply will not run under any other circumstances via WinXP.
It has its bugs but it is the best I’ve been able to find and I spent several weeks looking through most of the search engines/gaming resources.
Or just follow the link that Tom provided a few posts up. 
Or you could create a dual-boot machine. I boot to Win98SE to run Duke Nukem and the Quest for Glory and Xwing collectors editions. Also my TV tuner works better under 98SE than under 2KPro. And now that I think about it, there’s some serious software problem with watching DVD’s on my Win2K boot. It works fine when I boot 98SE. I should look into that. Oh, yeah, for some reason the hat switch on my Thrustmaster Fighter-X joystick doesn’t work under Win2K. I sent 'em an email about it and they said
Dear Customer,
For whatever reason the Hat switch for the X Fighter joystick does not work under Windows 2000. The problem is that the X Fighter uses Thrustmaster flight control system or 2 axis, 4 buttons with POV and Windows 2000 does not recognize the POV at all. The joystick isn’t broken as it would work under Windows XP or any older O.S. Unfortunately we do not have a fix for this problem.
Best Regards,
Philippe Gadouas
Hercules, Thrustmaster Technical support specialist
So anyway, my point is that there is a whole host of problems that can be sorted out with a dual-boot system.
I used to play this game called Galactix that was something of a Galaga rip-off. That was 20 years ago on my 8 MHz, 1 MB RAM, 16 bit Tandy. When I put it in now everything moves so fast it’s just a blur.