U.S. Robotics V.92 56K Faxmodem - PCI - 1 x RJ-11 Modem - 56 Kbps-by US ROBOTICS

I had an opportunity to get this old external u.s. robotics 56k modem for about $10 and I thought why not even though I don't have a phone line and don't know what I'm really gonna do with it but I can do some experiments with it it's got a phone line jack and a pass-through for a phone and some configuration dip switches described here on the back and a 25 pin serial cable and the wall adapter came with it but what am I supposed to do with this well the first thing is to try it out even though I don't have a phone line I can still make sure it's not dead on arrival so powering it on well I get that light so it's alive and as for hooking it up well I don't even have a serial cable but I did find this old USB to serial db9 port so you plug this in to USB and it will give rs-232 9 pin serial port access but I don't see any markings that tell me what brand is this and what kind of drivers