I have buy a socket 7 system (I'm not able to buy a i486 in my country) to do catchchallenger server benchmark (need few KB of RAM, work on DOS and ESP32).

I add this problem:

• No power supply AT
• No working disk (No way to have in my country)
• No floppy (No way to have in my country)
• No keyboard (No way to have in my country)
• No graphic card (I had 1 in PCI)
• To big, fan was not working (with very long cable)
• Bios blocked on: Floppy disk(s) fail (40) + CMOS checksum error - Defaults loaded + Press F1 to continue

Then my solution:

1. To work without keyboard I have modified the BIOS to just boot no mater what happen (verified and dev with 86Box)
2. Patched BIOS to take care of my network card with PXE ROM
3. Patched BIOS for HDD of more than 128GB just in case
4. Do PXE ROM for my network card
5. Electrical fix, AT power from ATX module power modified using a basic 12V 3A power adapter with the classical on/off power button

The result: very compact, silent, diskless boot, perfectly working on freeDOS and modern Linux (gentoo). I attach photo of my dirty work. MSDOS not tested yet.