it may well have come with an adapter for a 9-pin RS232 serial port. Those mice from a decade or more ago would have contained the software to recognise the interface into which they were plugged ...

Old Macs used the serial port for printers. Also known as an RS-232 port, serial ports provide very slow speeds and have been superseded by USB on desktop computers. USB-to-serial adapters are ...

We know, you’ve already got a USB to serial adapter ... With the ability to be directly plugged into a RS-232 port, this adapter will certainly catch the eye of retrocomputer enthusiasts.