|A 9 (or 25) pin pin D-sub serial port can be used for several things - a serial mouse is one of the most common things connected to one, but that doesn't make it a mouse port. |
A simple really inexpensive PS/2 to serial port gender adapter, with no internal circuitry other than simple wiring, will not allow a mouse to work unless the mouse is a "combo" mouse that is designed and wired up to be used with either type of both types of a connection, and the internal wiring of the adapter varies and must match what the mouse requires. Been there, done that. I have a few such mice and matching adapters, but they are OLD, made before about 1990. A "combo" mouse originally comes with the proper adapter.