This listing is for a BRAND-NEW, in-the-box, highly-customized Retro gaming and/or legacy PC, configured for full support of DOS, Windows 98SE, and Windows XP.  This was built with all new or new-old-stock parts.

Features:
-Bootable into DOS, Windows 98, or Windows XP
-DOS boot menu with options for loading mouse and/or CD drive drivers
-Aureal Vortex sound card with Soundblaster and FM support in DOS
-Radeon x700 Pro video card for excellent benchmarks and high Windows 98 compatibility
-3.5" 1.44MB floppy drive

Included:
-PC
-Power Cord
-DVI to VGA Adapter

NOT INCLUDED are a keyboard or mouse or monitor.  I strongly suggest using a PS/2 keyboard and mouse (green/purple connector instead of USB) as you may run into compatibility issues on Windows 98 with a USB keyboard or mouse.

Specs:
-Fractal Design Micro-ATX Case
-ICH7-based motherboard (exact model dependent on my stock)
-Intel Core2Duo E8400 CPU (Windows 98 and DOS only see 1 of the 2 cores)
-128GB Lexar Solid State hard drive
-2GB PC2 DDR2-800 Ram
-ATI Radeon x700 Pro (FireGL v5000 w/x700 BIOS) Video Card
-Aureal Vortex 1 Sound Card
-3.5-inch HP 1.44MB Floppy Drive (encased in a 5.25" bezel)
-100MB or 1GB Ethernet port (depending on motherboard)
-OEM CD-RW/DVD-RW drive
-350w Powerman OEM Power Supply

Ports:
-6 USB 2.0 ports (2 front/side, 4 rear)
-Dual-DVI (plus VGA with included adapter)
-PS/2 Keyboard port (keyboard NOT included)
-PS/2 Mouse port (mouse NOT included)
-Audio out
-Line-in
-Mic-in
-Parallel Port
-Serial Port
-Ethernet Port

Benchmarks:
All Benchmarks were run at default settings.  3dMark99 was run in Windows 98, 3dMark01 and 03 were run in Windows XP

3dMark99
34,990 3D Marks
79,964 CPU Marks
396 FPS - Race
313 FPS - First Person

3dMark01
25,035 Overall
157 FPS - Car Chase - High Detail
235 FPS - Dragothic - High Detail
190 FPS - Lobby - High Detail
112 FPS - Nature

3dMark03
8,050 Overall
263 FPS - Wings of Fury
51 FPS - Battle of Proxycon
46 FPS - Troll's Lair
54 FPS - Mother Nature

About This Build:
The sweet spot for this build is Windows 98.  It will run the vast majority of the Windows 98 game library without issue and at full settings.  The FireGL v5000 video card has the same chip as the x700 Pro and as such, works fine with an x700 BIOS (which I have uploaded to the card) - this card is second only to the x800-x850 series of cards and its nVidia equivalent is somewhere between a GeForce 6600 and 6800.  The Aureal Vortex 1 sound card offers compatibility for all 3 operating systems and supports quite a few later-generation DOS games.  Unlike most of my other hybrid builds, I have included a 3.5" floppy drive as this is one of the fastest motherboards out there that still has a floppy port on it.

The computer is completely ready to go right out of the box.  When you turn it on, you will be greeted with a menu where you pick from XP or 98/DOS.  If you pick 98/DOS, you will get a second menu where you pick from 98 or DOS (with various configurations).

I decided to format the XP partition as NTFS such that 98 and DOS can't see it - this allows for the CD drive to natively get assigned the letter D as opposed to a later letter (this is important for some CD-based games that have copyright protection dependent specifically on a disc being inserted into the D-drive).  I've also loaded DOS drivers so even when booted into DOS, you can access the disc drive as letter D.  I formatted Windows 98 as a 32GB FAT32 partition while allocating the rest of the space to XP.

Software:
NO GAMES are included.  On the Windows 98 side, I installed DirectX 8.1, Sea Monkey Web browser, an unzip utility, the TCP optimizer patch (for increased downlaod speed over the network card), and the universal external drive driver (for flash drives).  On the XP side, the installation is fairly close to stock, with Google Chrome v49, Firefox v52, K-Meleon v76, .net framework, c+++ redistributables, and DirectX 9.0c (video card supports through 9.0b).

Game Compatibility:
No hybrid retro system such as this one is going to offer 100 percent compatibility in both Windows 98, and XP - it is simply impossible due to the hardware needs of the different games for different eras.  My goal here was to get that percentage as high as possible.

That said, this system should play a large percentage of games released roughly between 1995 and 2004 (or later depending on the requirements of the game).  If you have any specific games you would like tested on this system, please message me and if I can track the game down, I'll do my best to test it.