The Small Computer System Interface (SCSI) serial port drive is a rather old port that computers used to use to connect to printers and, possibly, old gaming controllers. However, these kinds of ports have long been abandoned. So, if you own an older printer or piece of hardware that requires a SCSI port, you can use a USB-to-SCSI adaptor, which essentially converts a USB port into a SCSI port.
Connect a USB-to-SCSI adaptor into one of the available USB ports on your computer.
Connect the SCSI serial port to the old hardware you want to connect. You may notice your computer doesn't state that it's detected a new piece of hardware.
Insert the adaptor's driver installation disc into your computer. This driver tells the computer how to read the SCSI adaptor. Wait for the installation wizard to load, and then follow the prompts to complete the set-up.
Insert the floppy disk driver for your older hardware into your computer. If you don't have a floppy disk drive on your computer (most new computers don't), you can purchase a floppy disk drive that can connect to your computer via a USB cable. Install the drivers for the disk drive before inserting the SCSI driver installation disk.
Open "My Computer" (or "Computer" for some versions of Windows), and double-click on the floppy disk drive icon. This loads a window that contains all of the information on the disk. You'll see an icon that says "Install" or has an ".exe" at the end of the file name. This is the driver. Double-click on this to begin the driver installation. Follow the prompts to complete the set-up. You can now begin using your SCSI hardware on your computer.