Molex Floppy Power Splitter Kickstart C64 FDD Dual PSU Modern

C64 FDD Dual PSU Modern Gray EU - Quick Start (Italian)

for which the pin-out was somewhat similar to the internal 8-bit expansion ports used by IBM on their machines at the time (later known as ISA ports)

you can get the source files and do your own changes

From the Greaseweazle wiki:

if not impossible

Molex Floppy Power Splitter Kickstart C64 FDD Dual PSU Modern4 pin Y power splitter cable to floppy power. For connecting two 3. 5" floppy drives to one molex power plug internally in retro PCs. From: 1 x male 4 pin molex power connector To: 2 x female 4 pin floppy power connectors Cable length: 20 cm (including connectors)