First post, by sirnephilim
Was tossing this idea around lately, probably not going to build it - at least this week - as I'm usually all about maximum compatibility for the era in question. But I was going over what hardware, OS, etc. I'd run to cover the largest chunk of retro IBM PC games in one system.
Just going by memory, Windows 98 would probably be my starting point. I recall most DOS games that weren't locked to the CPU clock worked at least well enough back then, many working nigh perfectly if tweaked right. Anything XP or later has at least a reasonable chance of working on modern hardware so can be discarded from consideration fairly safely, and 16-bit Windows was still at least moderately supported - honestly the only games I remember playing in the 3.1 days were card based or Sim(Whatever). (One could always dual-boot for better DOS support.)
Hardware wise, we're on to a thornier issue. Win98 covered a lot of ground, honestly. You've got 3 major standards for video from PCI to AGP to PCI-Express, processors ranging from hundreds to thousands of megahertz, and two major CPU brands to consider in AMD and Intel - both being VERY competitive at the end of 98's run. (I was an AMD fanboy at the time but have no real loyalty beyond price and performance.) Sound cards are somewhat easier, as one was quite often as good as another when it came to Windows games in 32-bit mode, and most at least worked with DOS games even if it wasn't perfect.
So my imaginary rig would go as such:
Motherboard: Intel LGA775 /w PCI-Express
Brand wouldn't matter much, ASUS would be a fairly safe bet for this architecture. The capocalypse was a thing back then though, so check the pics for damaged/bulging capacitors. Yes, this is from the tail end of Win98 hardware support, but the idea is to run things as well as possible over as wide a date range as possible.
CPU: Pentium 4 661
Core 2 seemed like gilding the lily, as anything made to run on 98 would have vastly more than enough power from the venerable P4. And the P4 is probably the cheapest part thanks to widespread corporate adoption at the time. That said I'd go for the ultimate P4 because the numbers are bigger. Honestly though, anything 2GHz or better will be miles beyond what is necessary. Intel was a fairly obvious choice thanks to vast availability and low cost of both motherboards and processors of the era.
Video Card: GeForce 7950 256MB PCI Express
Windows 98 was known to have problems with video cards above 256MB, and some ATI cards had issues with DOS graphics modes. This would arguably be the fastest nVidia 256MB card with Win98 support.
Sound Card: Sound Blaster Live! 5.1
Actually decent DOS support plus easily available Win98 drivers. Hard to go wrong there.
Case/PSU/HD/Optical: Any
An LGA775 board with PCI Express would de facto have SATA support and be an ATX form factor of some stripe. This drastically simplifies hardware choices as a crappy SSD, no-name DVD drive and any old case and PSU would work just fine here.
Note again, I wouldn't absolutely recommend this build for gaming in any era other than Win98 specifically. This was a thought experiment to figure out what I would build if I wanted to cover games from the late 80's up to the mid-2000's. Puttering around on the E of Bay tells me that this system could be parted out for around $250 if you were frugal and clever, so it may very well be a viable retro system for those on a budget or with space constraints. Though it must be said that your DOS game experience would likely be better in an emulator, your Win98 gaming would be great to excellent.
