I have a MSI MS4144 motherboard. I think it has a unsoldered PS2 connector on the board up by the DIN KB connector, but that probably means there are missing surface components for it. Some of these boards probably came with PS2 KB and mouse.
Nice board, but I wish it had 4 PCI. Don't need all those ISA slots. It'll run every CPU ever made for Socket 3 though.
And yes I do have a serial to PS2 adapter. Like said above though, the mouse has to support serial or it doesn't work. T fhe only mouse I could find that worked with serial is a POS generic ball mouse (PS2+serial) that was the last one in stock at a computer shop.