Hi!

Let's jump right into it.

Specs:
Case: Inwin IW-Q500 BigTower
Board: ASUS P3B-F (440BX)
CPU: Intel Penitum 3 Coppermine 600E (at 800EB via FSB 100 --> 133, no additional voltage required for stability)
RAM: 512MB (2x 256MB) Infineon PC133
Floppy A: Alps 3-1/2" HD 1.44MB
Floppy B: Teac 5-1/4" HD 1.2MB

Storage Controller 1: onboard IDE:
Pri Mas: [HDD] Fujitsu MPC 4,3GB (period correct drive for Win98) - has 98 installed
Pri Sla: [HDD] Samsung SpinPoint 80GB (just for Data Storage)
Sec Mas: [HDD] UltraATA 100 Hot Swap at the front - of course bootable, so I can experiment with different OSes without touching the existing installations.
Sec Sla: [ATAPI] IOMEGA Zip100 - works fine also when there is no drive in the bay above.

Storage Controller 2: Adaptec AHA-2940UW over PCI
SCSI ID#0: [HDD] IBM DPES-31080 1GB 50-pin SCSI - has CDU MS-DOS 7.10 with WfW3.11 installed.
SCSI ID#3: [ODD] Pioneer DVD-305 (DVD-ROM) 50-pin SCSI - It's a slot loader!
SCSI ID#4: [ODD] Yamaha CRW (CD-R(W)) 50-pin SCSI

Graphics card: Matrox Millenium G400 Max Dual-Head 32MB AGP
Sound card: Creative SoundBlaster AWE64 CT4500 ISA
Network card: Intel PRO/100 Server Adapter PCI
USB: NEC USB2.0 5-Port PCI card - nice to have, not period correct, I know
PSU: FSP Group 350W ATX-Power Supply (more modern with 24pin ATX and PCIe-power, explanation below)

I have tinkered with this build for years now and just changed the platform (ASUS P5A --> ASUS P3B-F) a few days ago.
Am really happy with the new platform that I decided this will be its final form. If I change something, it will be something minor like a GPU upgrade or so.

Setup and tweaks:
The case has two HDD act-LEDs. The first one is connected to the onboard IDE, the second one to the SCSI controller.
The IDE cable that connects the Swap Bay in the front and the ZIP drive has its Pin 39 cut so the hard drive in the bay won't send its activity LED info into the IDE-LED1 on the case. Makes it really sleak.
One issue I had with that: The old board (P5A) needed Pin 39 to detect the different drives on the IDE channel. If you interrupt that pin on an IDE controller like that, it will only detect one of the drives. This was a massive issue because that meant that on the old platform, I was only able to put the Swap Bay alone on an entire channel. Making me unable to hook up the ZIP drive without installing a third freakin storage controller.

The power supply is a bit too new for the setup but I had decided on it as I didn't want an old 230W noname thing that would explode in my face immediately.
This supply now has the 4pin EPS, 6pin PCIe, 240pin ATX etc. I tied every too new cable together and tucked it in behind the supply out of sight.
Also it only had 3 Molexes. I sacrificed some trash supplies, cut off their Molex harnesses and soldered them (properly, this is not a bodge) onto the existing harnesses on the FSP - still needed Molex Y-Splitters though.

These are just the tweaks that are still in place - there were so many more.

If you have any thoughts for improvement - I'd very much like to hear it!