A simple converter can be sourced online, but the only thing he could find locally that was even close was a USB to RS-232 converter. He used that component to craft his own USB to RS-485 bridge.

KKSystems’ isolated USB-to-RS232 and USB-to-RS422/RS485 converters from Saelig can be used with computers that do not have a serial port or where an extra serial port is required. Outfitted with 39-in ...

The Nucleus USB to RS232 adapter class driver has been designed to work with USB to RS232 converter hardware to solve the aforementioned problem for embedded hosts. Therefore, this class driver allows ...

And if you were to go back a few more years into the past, you’d have found when you bought a mouse with a PS/2 connector fitted, it may well have come with an adapter for a 9-pin RS232 serial port.