Here's the third build I did, and probably my most pleasing retro rig. Enjoy!

System specs
OS: DOS 6.22 (Primary), Windows 95 OSR 2.0 (Secondary)
CPU: Pentium MMX 166 with Startech cooler
Motherboard: ASUS P5A Super Socket 7 Motherboard Rev 1.03 (ATX): ALi ALADDiN V Chipset/1x AGP/5x PCI/2x ISA
RAM: 32mb SDRAM
Graphics: Diamond Stealth 3D 2000 (S3 ViRGE)
Sound: Yamaha YMF 719E-S, ESS 1868F (BTC 1855/1853L)
Storage: CF to IDE adapter (4gb CF card for DOS, 8gb card for Windows 95), Lite-on DVD/CDRW drive, Gotek Floppy emulator
Case: Enlight EN 7230 ATX
PSU: Enlight EN-8341934

Purpose
This is my third build. Following my Pentium 4 (Thor) and Ivy Bridge (Jupiter) builds, I decided I wanted something a little more ‘old school’ where I could play around with ‘pure DOS’ and things like ISA sound cards.

Thor proved to be a mostly reliable DOS machine, at least for later DOS games, but it isn’t optimised for it, and it has compatibility issues from the graphics card, CPU speed and the Audigy 2 ZS’s Sound Blaster 16 emulation.

Like many of you, DOS is where my gaming journey began (along with an Atari 2600). I was playing DOS games with my Dad, younger brother, and cousins in the early 90s on our IBM 286 (a hand-me-down from Dad’s work). I learned to type by playing sierra adventure games (Leisure suit larry mostly, highly inappropriate). We moved on to a Pentium 133 with Windows 95 in 1996 where I experienced some of the later-period DOS games (albeit as Windows titles). That was a revolutionary machine in our eyes.

The objective of this build was to have a machine focused on DOS-era gaming that can comfortably cover as much of the DOS era as possible (ie, late 1980s up to 1996/7). The secondary objective was to recreate the ‘nostaligia’ of my family’s Pentium 133.

Originally, I set out to go wider than this and to explore the super socket 7 platform, and magic of the 3Dfx Voodoo3. I abandoned those plans for two reasons:

1. I didn’t want to dismantle this machine once I had made it, as I loved it so much)
2. I had been captured by the allure of Slot 1 and the mighty 440bx chipset and decided to explore the 3Dfx Voodoo3’s capabilities on that platform instead. This lead to my next build, Neptune.

Overall, I am really enjoying this rig. It’s probably the most-used of all my builds (including monthly titles played by the DOS game club) and I learnt a lot by building and setting this machine up. I still haven’t explored it to its fullest potential either, so that is very exciting and means lots of fun and optimisation ahead!

Background and planning
I started with my first parts purchase in mid-2023, and pulled together the first iteration in September that same year. The rig’s fundamentals have largely stayed the same, with lots of tinkering in between.

Planning for this build was straightforward. With the experience gained from getting my hands dirty on my previous builds, and having done a lot of reading these forums, I roughly knew what I wanted and needed. Sound cards are the exception, as you’ll read later.

I also did a few dry runs on PCEM to make sure I was configuring and installing everything correctly (while still waiting for my hardware to arrive). This was a very valuable learning experience.

I based this build around socket 7 and the Pentium 166 MMX CPU because of the ability to play a wide range of speed-sensitive DOS games by disabling L1 and L2 cache and using SETMUL. Phil’s videos covering this topic were the main influence. I also wanted to go with the ATX form factor to future proof as much as possible with things like cases and PSUs, another tick for socket 7.

I kicked this build off by buying a 2001-era computer in a very good condition beige case with minimal yellowing. The computer came with an Abit NF7S v2.0 motherboard, Athlon XP 2600+ CPU, and a Geforce 3 Ti 200. A decent rig in and of itself, but I only wanted the case (I have kept all the other parts though, you'll notice it still has a misleading Athlon case badge). The previous owner had taken great care of it and still had all the pieces and boxes that came with the parts, a rare find these days.

Other parts were sourced either locally or via Ebay and this went well for the most part (but see the sound section for some speed bumps there). Ebay tends to be a bit pricey where I live so I do end out paying a premium for parts on there (or waiting forever for parts to show up locally), but ultimately it’s worth it!

I wanted to name this computer after a Wolf as the first game I played on it was Mechwarrior 2 (one of my all-time favourites). Naturally, I’m a Clan Wolf guy, so in keeping with my theme of mythological beings, it had to be nonother than Fenrir.

Planned upgrades/changes
Although fully operational, this build is still a work in progress. I will upgrade the case fans and PSU at some point, but that’s minor stuff. The two main things I need to do are:

1. Add a 3Dfx Voodoo Graphics card for early glide compatibility (I purchased one on Ebay, but it was DOA and I am prioritising other parts first) - while I have a Voodoo3 system, some games (like the 3dFX version of Mechwarrior 2) only run on a Voodoo1, and so this is intended to cover that off
2. Settle on an optimal sound card combination. Either a SB16 or AWE64 Value + Yamaha YMF71X, or just a fully-functional Yamaha YMF71X on its own (see sound below for more details on my journey). I’d also really like to play around with a PicoGUS if I can get my hands on one.

I may eventually replace the (Super Socket 7) P5A motherboard with a Socket 7 board with an intel chipset. I don’t use most of the SS7 features, and it would also be nice to have more ISA slots. This is not a high priority, and probably only something I will do if I can get a good deal locally (so in other words, very unlikely).

I’m also debating whether to go to an SD to IDE adapter rather than CF, as CF cards seem to be a bit rarer now, and SD cards are much cheaper and abundant. Keen for people’s thoughts on that, I know the CF to IDE compatibility is much more straightforward.

Operating systems
DOS 6.22 is the primary OS. It’s installed on a 4gb CF card split into two 2gb partitions. I may install Windows 3.11 on here, but I have no practical use for it and no real nostalgia for it either having not had a computer running it.

Windows 95 (OSR 2) is installed on another CF card. I don’t have a huge need for this either as there aren’t many games I play that won’t work in either DOS or on one of my Windows 98 machines. Mechwarrior 2 is one of those though (Yes, I can play this in DOS but I own the pentium edition, which has issues on my Pentium 4) so that’s a good enough reason to have this I suppose!

Despite not having much practical value, this OS brings home the nostalgia in a way that my other machines do not, which is why I keep it around. I even used the original Windows 95 installation disc from my family’s Pentium 133, which was quite special.

Once I get a working Voodoo, the Windows 95 installation will be handy for games like Mechwarrior 2 (3dfx version) and Interstate ‘76 (which I can’t seem to install on my Voodoo 3 system).

Motherboard, CPU, and RAM
The Asus P5A motherboard is well-regarded and I have no complaints. As a Rev 1.03 board, it doesn’t suffer from incompatibility with AMD K6-3+ processors as has been documented with later Revs. It has 512kb of onboard Cache (I think, need to verify) which is more than enough for my needs, and the two ISA slots are handy for multiple soundcards.

It’s definitely over-specced for this machine (as mentioned earlier I originally intended to try another build on this which is why i got it) and there are a bunch of features I don’t utilise, such as the AGP slot (which I would ideally use under Windows 98 as the drivers don’t like my Windows 95 installation), so a ‘downgrade’ to a regular Socket 7 motherboard is definitely an option.

The Pentium MMX 166 CPU is the flagship component of this machine. It’s more than adequate for the games I play on here. Games requiring a more powerful CPU can be played on my Pentium III or 4 builds. As mentioned earlier, the main reason for choosing this CPU is the ability to slow the machine down to 386 and 486 speeds by disabling cache and using SETMUL. It’s also a fairly affordable and abundant processor. I’m yet to get into any of the speed sensitive games just yet as most of my nostalgic gaming is from the late 90s/early 2000s, and some of the earlier titles I play aren't speed sensitive, but I’m sure this feature will come in handy in the future as my circle of games expands.

I have 32mb of SD RAM installed. I have a 64mb module available, but I don’t see any need to upgrade at this stage.

Graphics
I have a Diamond Stealth ‘3D’ 2000 graphics card which has an S3 Virge 3D decelerator chip. It has (I think) 2MB of RAM. It does 640x480 2D DOS and Windows gaming comfortably, but I wouldn’t want to (and don’t need to) push it much further than that.

There was no strong reason for picking this card over, say, an S3 trio. I was mostly looking for a card that was ‘good enough’ and I picked it up relatively cheaply as part of an untested set of graphics cards being sold locally. It has good DOS compatibility, and the ability to play with S3D is also a bonus, but I’m yet to do this.

While I could run an AGP card on this machine, I feel no particular need to, and doing so would likely require upgrading to Windows 98, which is outside the scope of this particular build. Again, I have more powerful machines with AGP cards already.

Sound - internal
Sound has been my biggest challenge, but also where I get to do most of my tinkering, which is what I really enjoy about this hobby. Exploring ISA sound cards was one of the reasons for making this build, so it’s been both a frustrating and fun experience.

Like many of you, I’ve been sucked into the quest for the ultimate ISA sound card combination (I think we can all agree it has to be a combination rather than one card, right?). I’ve poured over threads looking at the merits and demerits of different soundcards. Listened to comparisons of OLP3, CQM, ESFM and so on and so on. I’ve looked into things like Soundblaster Pro stereo compatibility, 16-bit sound compatibility (or is it 16-bit mixing with 8-bit samples?), hanging-note bugs, single-cycle DMA clicking, and looked at all the different models of soundblaster. While I think I understand it, it’s an absolute rabbit hole and I’m still only part way down. Most likely however, I’m overthinking it.

I’m yet to land on the right combination just yet, partly due to some bad luck with broken sound cards, and partly because I still want to play around with things.

For now, I’m using an Axra implementation of the Yamaha YMF719E-S, and a BTC 1855/1853L which is an ESS Audiodrive 1868F.

The Yamaha card has a broken MPU-401 that I don’t have the skill to fix just yet. It’s my primary sound card, set to port 220, IRQ 7, DMA 1, MPU-401 at port 300. This card on the whole sounds great, and is in really nice condition (I got it boxed and everything). It has genuine OPL3, sound blaster pro 2 support and, on paper, bug free MPU-401. In my eyes, it’s close to the perfect card. It’s just unfortunate that my particular card is imperfect. Once the drivers are set up properly, this thing goes great.

I had planned to pair this with an AWE64 Value, but two things went wrong. First, the MPU issue noted above, and most significantly, the AWE64 I purchased was DOA and has since been passed on to a fellow retro enthusiast with more skill than me.

The ESS Audiodrive is basically used as a dedicated MPU-401 and is set to port 240, IRQ5, DMA 3, with the MPU-401 port at 330. I also use this for CD audio as my Yamaha has very quiet CD audio and I need my NIN turned up LOUD when I play Quake (which, truth be told, I don’t actually do on this machine). The drivers for this card are straightforward and easy to use.

This wasn’t the first sound card combo I used. I originally had the ESS doing sound duties on it’s own, while I built my sound card collection. While it does the job, there are some aspects I find sub-optimal. Mainly, the sound is very ‘thin’ when the internal amp is disabled even when played through amplified speakers (this could just be an issue with my card) and then way too loud when it is enabled (requiring everything to be turned down on the mixer). For this reason, I prefer to use the line out of the YMF card for digital audio and FM synth (otherwise I’d have just stuck with the ESS).

I also have a Vibra-based Sound Blaster 16 I can utilise, but that is currently taking care of late-era DOS gaming duties in my Pentium III rig, Neptune. This model is a CT2800 which also has genuine OPL3. For a while I used this card in this rig exclusively, until I got my externa Roland module (the Ghost notes are baaaad on this card) after which I paired it with the ESS card. I may revert back to this pairing once I find a suitable replacement card for my Pentium III rig (or possibly pair it with a working YMF71X).

Needless to say, it’s sound card musical chairs in my home office, but I kinda like it that way.

Sound - external
I supplement my sound cards with two external devices:

• a Roland SC-88ST pro
• a Roland UM-ONE plugged into an old Laptop.

This relieves some of the issues of landing the perfect sound card combination. There are some games where I still prefer the OPL3 FM synth (Stunts, for example) but most of the time I’m using one of these devices for music.

The SC-88ST pro is basically a stripped down version of a standard SC-88 pro and much cheaper from what I can tell. A friend of mine kindly picked one up for me when he was travelling in Japan, otherwise I probably wouldn’t have one. Its only controls are a volume knob and a switch to put it into SC-55 mode, and as far as I can tell it doesn’t do MT-32 emulation. I tend to prefer the SC-88 sound setting, but that is totally subjective. Despite having fewer features than a normal SC-88, this isn’t really an issue for gaming, as I understand these aren’t necessary and are mostly for doing things like adding reverb etc.

In terms of I/O, it has a (noisy) headphone jack, AUX in and out, and MIDI IN and OUT (no MIDI thru). I send the line out of the Yamaha card into the SC-88ST pro’s AUX in, which mixes it with the MIDI. I then send the mixed signal to my speakers/headphones. This produces a much cleaner and higher quality sound than sending the processed MIDI sound from the module into the sound card’s line in, for whatever reason.

The Roland UM-ONE is also very useful for handling things like MT-32 emulation and playing around with other sound fonts. I use this in combination with SOFTMPU for intelligent mode MIDI where required.

Basically, I’m sorted for General MIDI and LA synth as far as I’m concerned. Now I just need an all-in-one sound card with a functioning MPU-401 port!

Storage
As mentioned above, I use CF cards for storage. I have a PCI bracket for this, and have to get down on my hands and knees to replace it, but that’s a small price to pay for OS flexibility (with the added benefit of physical flexibility)

The CF cards are GREAT for file management. I just hook them up to my modern PC and move files across/delete old folders etc. Super easy, and almost eliminates the need for a floppy drive. I will sometimes edit my config.sys and autoexec.bat this way too, but I do find this easier in DOS.

I do have a Gotek floppy emulator for when floppies are needed (ie, installing DOS, certain games etc.). I don’t use this a whole lot, but I’d be kinda screwed without it on a PC covering this era.

I also have a generic lite-on CD/DVD drive that I got as NOS. It’s very noisy at high speeds, so I use CDBequiet! to slow it down to 4x speed.

PSU and Case
As mentioned earlier, I started this build by buying a beige Enlight case that had been really well cared for by the previous owner, and came with all its original parts. It’s a bit of a pain to open and close, but the main thing is that it looks the part! It still has an ‘athlon’ case sticker that needs to be replaced, but who cares.

The PSU looks to be in good condition, but given that it’s probably more than 20 years old, will need to be replaced with something more modern. This computer doesn’t need -5V rail so a modern power supply should power this fine.

Miscellaneous
I have a few different tools that I use on my DOS installation. I’m keen to hear people’s thoughts for other tools that might be useful.

Phil’s DOS starter pack - superhelpful for different memory settings and CD/mouse drivers, especially for a dummy like me
Phil’s benchmarking pack - for obvious reasons!
SETMUL - as mentioned before, for slowing down the PC
SOFTMPU - for intelligent mode MIDI without hardware
NOVERT - really important for playing DOOM, HERETIC and other FPS games with a mouse without that annoying forward movement from pushing the mouse forward
CD Be quiet! - for slowing down my CD drive speed do my wife doesn’t complain about my CD drive trying to send my PC into orbit

Peripherals
For convenience/space, all my computers use the same (mostly modern) peripherals:

• Screen: Dell P2423 - a 1920 x 1200 Monitor that I use in 4:3 mode for my retro machines, and 16:10 for my modern computers (no gaming on those though!)
• Keyboard: Leopold FC990R in classic beige with Cherry MX Speed Silvers. This Keyboard is USB and PS/2 compatible. I have a bunch of other keyboards, but this is the main one for my retro rigs. The speed silver switches are… ok… I prefer blacks but this was the last of this type I could get and they’re fine.
• Mouse: Cherry 5400 (grey), like the keyboard it is USB and PS/2 compatible, being grey is also a plus, but the main benefit is its optical! I have a trekker mouse (ball) too, but I have zero nostalgia for old computer mice… they can live in the past.
• Speakers: Creative T60s - nothing special, but they do the job
• Headphones: Sennheiser HD280 Pro headphones - I’ve had these bad boys since 2009 and they’re great. I have a baby and a toddler, so headphones are a must. I plan to pair this with a headphone amp
• Joysticks: Logitech Extreme 3D pro (Win 98 Win XP), Microsoft Sidewinder 3D Pro (DOS, Win95)

I have a manual KVM switch which is… me… I just plug/unplug each of my machines depending on which one I want to use at the time. Not the most elegant solution, but works for me.