System(s) Specifications

JST-NEFTET (my main PC)

Case: Fractal Design Core 1100.
PSU: EVGA 600BQ. Hauled out of retirement, its job isn't done quite yet.
Motherboard: ASRock B450M-Pro4.
CPU: AMD Ryzen 5 5700X. The CPU swap between the main and server didn't go to plan.
RAM: 32GB DDR4-3200 CL16, 2x16.
GPU: Intel Arc A770 Limited, 16GB.
SSDs: PM991a 512GB NVME m.2 (Windows C:), WD Blue 2TB SATA m.2 split 500/1500 Windows D: and Debian root/home.
ODD: LG (HL-DT-ST) WH14NS40 BD-XL MDISC burner.
Other goodies: Internal card reader/USB3 hub. bequiet! Pure Rock Slim CPU cooler. Inspur Intel X540 10GbE NIC.

OS: Windows 10 LTSC 2021 and Debian 12 dual-boot.

JST-CRAGSTONE (also referred to as the 486, 386 on stilts, et al.)

Case: Some chinesium ATX desktop clone. It also happened to have mount points on the motherboard tray for an AT motherboard. I had to modify a blank ATX IO shield with a hole for the AT keyboard port and swap the momentary power switch for a toggle. I also had to modify one of the side "lips" on the lid because the tolerances on this board were so tight I couldn't close the case otherwise!
PSU: SeaSonic SS-350ET. The 5V rail is a tad low at only 20A, so I wouldn't trust it with a Socket A board, but here it does just fine. The lack of -5V doesn't bother this board, either.
Motherboard: Alaris Cougar. Interesting that it's IBM manufactured and doesn't make a single reference to the PS/2 standard... Strange little 486 board that also has a 387 FPU socket since the CPU is 386-derived. The MR-BIOS is also interesting. 7xISA-16, 2xVLB, but curiously the super-IO is onboard and it's fantastic -- the IDE is local-bus, the parallel port supports ECP I believe, and both COM ports are using 16550A UARTs. 256K L2 cache, 12ns chips. I modified my MR-BIOS with help from a friend to stop the CPU from being forced to a 3x multiplier so I could overclock the system bus to 33MHz.
CPU: IBM 486 "Blue Lightning", BL3-75 at 2*33 for 66MHz. A little background: IBM's agreement with Intel back in the day was that they could manufacture licensed Intel parts or modify them how they saw fit, but they could only sell them as part of a computer or major assembly like a motherboard, or as they'd call it, a "planar." The IBM branded CPUs you could actually buy loose were Cyrix parts manufactured and sold under license from them. An interesting design: they borrow from the 486SLC they loved to use in their PS/2s to give them "486" parts but keep the boards cheap. This, however, is fully 32-bit. It did inherit its cache control logic from the SLC though, so it can only cache 16MB of RAM -- problematic to say the least for use under Windows 9x. It's clock tripled by default and can understand i486 instructions but it behaves much like a 386 in other ways (and has a 387 FPU socket, as mentioned earlier). I gained more from overclocking the system bus than I lost from underclocking the CPU, so it's staying like this. FPU is an IIT 4C87-DLC40 at 33MHz.
RAM: 1x16MB FPM 72-pin SIMM. Windows 9x fills in the memory map top-down, so with any more than that it's running mostly uncached which is a big problem.
GPU: Cirrus Logic GD-5428 1MB VLB. A much more sensible, compatible choice for this machine -- the drivers for everything blessedly work and I have no complaints. This machine's CPU is slow enough that I really don't notice much of a performance drop from the S3 card I had before -- that's mercifully been retired to being a display piece, itself.
SSD/HDD: 2GB SD card in an SD to IDE adapter on the onboard local-bus IDE.
ODD:: Lite-On LTD-163D. It's beige, can read any CD I throw at it and any DVD too which comes in handy for data DVDs, has analog playback with a headphone jack and play/pause and stop/eject buttons. I can't ask for more really. It lives on an ISA secondary IDE card, as the onboard local-bus IDE doesn't like ATAPI drives unsurprisingly. That was really hit or miss back in the day to the point that stuff that worked that way was the exception rather than the rule.
Other goodies: CT2800 Vibra16S for sound. It has a real OPL3, and supports being initialized using DIAGNOSE and the BLASTER variable. I can't ask for more -- it's basically just an SB16. 3C-509B for LAN, disabled XT-IDE 386+ ROM in the socket as the onboard BIOS handles drives of this capacity fine and NT likes to freak out with the ROM putting the IDE controller into int13h mode with no specific driver. 1.44MB 3.5" floppy drive A:, 1.2MB 5.25" floppy drive B:. AVA-1502E ISA SCSI card, only an external 25-pin port -- no internal header or boot ROM. This connects to an external SCSI Jaz drive.

OS: Windows 95C. It boots and primarily lives in DOS, but networking is generally easier and more reliable under Windows, and there is a small cross-section of software that requires a Win32-capable OS and runs acceptably on a 486-class machine. Despite my having previously stated the opposite, on here with only 16MB of RAM and a slow 386-derived CPU 95 is definitely quicker. I modified this install using Nathan Lineback's instructions ons on ToastyTech to remove both IE3 and 4 from the setup files, but I installed IE5.5SP2 both for the runtimes and because that version has the best balance of features to speed on this hardware.

JST-RITHWIC (also referred to as the P3)

Case: Unknown turn-of-the-millennium ATX beige tower case. It's not bad, it's got some neat features, but it's nothing super special.
PSU: Another SS-350ET. Nothing special, no complaints.
Motherboard: EPoX EP-61BXA-M. 440BX chipset, 4PCI 3ISA. Ironically right now I'm not using any of the ISA slots, I could really have used one more PCI slot even, but the option is nice.
CPU: Intel Pentium III 450. Katmai core; just a Deschutes Pentium II with half-baked SSE. I don't think this board's VRMs are able to go low enough for Coppermine, and besides, this particular model has sentimental value to me. Incidentally I was panicking over trying to cool the L2 cache chips (on Katmai, they're separate from the CPU die) but after finally filing down some MOSFET heatsinks to fit and thermal-taping them to the chips, I uncovered literature saying they're meant to be left uncooled and that cooling them if it does anything at all just makes it a bit easier to overclock.
RAM: 256MB PC100. It's actually rated for 133, and the board can actually clock that high, but I'll burn that bridge when I get to it.
GPU: 3dfx Voodoo3 3000 16MB AGP. Was there really any other option?
SSD: 128GB SD card on an IDE adapter. Saturates the UDMA-33 controller of the 440BX chipset easily -- I actually feel quite bad for running this on the built-in IDE, but I'm in no mood to tangle with IRQ conflicts -- I barely got this thing playing nicely as is. To make a long story short, never use the bottom PCI slot. It always shares resources with the others.
ODD: BTC 4816IM. Cheap, cheerful, burns CD-R/RWs and reads DVDs of all stripes. Has CD audio playback with separate play/pause and stop/eject buttons and a headphone jack. It does pretty alright.
Other goodies: 1.44MB 3.5" floppy drive A:. Intel PRO/1000GT for LAN, YMF744 for sound (with working SB-Link for DOS!).

OS: Windows 98SE. IE 6, KernelEx 4.5.2019.23. NT5.x isn't suitable due to its lackluster support for the sound and video card used here, and the later SVGA and of course 3dfx-accelerated DOS games run brilliantly from within Windows 98. I elected to leave 98lite out of the equation because adding yet more variables to such a machine when I have plenty of resources is just dumb.

JST-SHOUSHI (Nostalgia Express)

Base Unit: Dell Dimension 9200. A bit of a stretched version of the E510 platform that I had as a child shortly before my Inspiron 530.
PSU: OEM Delta(?) supply. Those things had to power Pentium Ds. I completely trust it in this application, and I'm not stressing it either.
Motherboard: Dell CT017. P965 chipset, from what I understand it has either a 3 or 4-phase VRM. The way I see it, this was rated to handle Pentium Ds -- I could do my worst with the QX6700 and it wouldn't even sneeze at it.
CPU: Intel Core 2 Extreme QX6700. The OEM board sees it as a Q6700, but it does clock fine in software using ThrottleStop.
RAM: 2x2GB DDR2-800 CL5. It can take 8GB, but that'd mess with the subtimings and 4GB is honestly plenty for this rig.
GPU: Quadro 2000 1GB. Simple, elegant, plenty fast for the application, and Vista does support DirectX 11 with a platform update.
SSD: TeamGroup T-FORCE 1TB SATA.
ODD: Generic black-bezel DVD+-RW. Does the job, looks alright doing it. Nothing special.
Other goodies: Onboard gigabit Intel LAN! Onboard sound because Vista is sad and doesn't do hardware accelerated sound anymore. 1.44MB 3.5" floppy drive A:, a strange choice for a 2007 computer, and a 3.5" internal USB card reader.

OS: Windows Vista SP2 x64, extended kernel; Debian 12 amd64 dual-boot. A strange choice, but considering this is an amalgamation/final form of sorts of two of my childhood PCs, it was down to either Vista or XP Media Center Edition 2005, and I have so many XP boxes already. Debian's there to do the things Vista can't, which, actually, isn't that much.

JST-DANBY (da Geode)

Case: Some CoolerMaster Elite thing. Very plasticky and gross but it's what I had on hand.
PSU: Antec 350W unit -- 35A on the +5v rail, very important seeing how this doesn't derive CPU power from a +12v connector.
Motherboard: ECS K7S5A Pro. I have mine modified with the honeyx modded BIOS.
CPU: AMD Geode NX 1750 @ 1500MHz. Essentially a very heavily binned Thoroughbred-core Athlon XP.
RAM: 1GB in the form of two 512MB DDR-400 sticks -- running at DDR-286, 143FSB, 2-3-2-6-8.
GPU: GeForce4 Ti4200 128MB. I must have a golden sample or something, because this thing clocks like a mother. It'll easily do Ti4400 clocks and come very close to Ti4600 clocks. This much with a passive heatsink that I cool with a 120mm fan bracket in front of the card.
SSD/HDD: 256GB SSD on Startech SATA to IDE adapter.
ODD: Generic IDE DVD+-RW drive. Does the job. Nondescript.
Other goodies: 1.44MB 3.5" floppy drive A:. Intel PRO/1000GT NIC. Audigy2ZS.

OS: Windows XP SP3, Debian 12 i386 dual-boot. I have XP skinned and tweaked within an inch of its life to essentially be, at first glance, Windows 2000, except I branded it as Windows 2002 with the help of the Inexperience patcher.

JST-SAWATO (AMP)

Case: Antec Plus 1080 in Blue.
PSU: LSP 500W unit -- this board derives CPU power from the +12v rail, so a strong +5v rail is a lot less needed here ironically.
Motherboard: MSI K7D Master. AMD 761MP chipset.
CPU: Dual AMD Athlon MP 2000+s. 1.66GHz of double-stuffed Palomino power!
RAM: 2GB in the form of two 1GB DDR-400 sticks to run FSB266 at very favorable timings.
GPU: ATi Radeon 9550, overclocked the daylights out of. This is actually an X1050 which is the same basic card but with GDDR2 RAM that'll run whatever clock the memory controller decides to give out at. RV350 is RV350...
SSD/HDD: 512GB SSD on Startech SATA to IDE adapter.
ODD: Generic IDE DVD+-RW drive. Does the job. Nondescript. Other goodies: 1.44MB 3.5" floppy drive A:. Intel PRO/1000GT NIC. Audigy2ZS.

OS: Windows XP SP3, Debian 12 i386 dual-boot. This one I actually let look like Windows XP.

JST-ADVOCATE (Proxmox host)

Case: Phanteks Enthoo Pro. Much more convenient for swapping in hard drives.
PSU: EVGA 750G5. Superflower OEM, very solid.
Motherboard: Gigabyte X470 Ultra Aorus Gaming. I needed the slots more here.
CPU: Ryzen 5 5500.
RAM: 64GB DDR4-3600 in 2x32.
GPU: GTX1070SC 8GB. It's been retired to media encoding duty, passed through to my NAS VM.
Storage: 1TB NVME SSD for booting, VM storage. 3x8TB WD Blue for mdadm software RAID5. Open hotswap bay for backup operations.
Other goodies: Datapath E1S PCI-E 4x VGA/DVI capture card (passed through to dedicated capture VM), Inspur Intel X540 10GbE NIC, bequiet! Pure Rock Slim CPU cooler, SATA hotswap bay for backups.

OS: Various; Proxmox VE host.