QNX4.25E-USB and a ZIP disk

I have just down loaded the latest USB offering. I have a USB ZIP disk connected. Running io-usb and using usb the zip disk is correctly reported. Then running Fsys.umass devno=1 & the zip disk is again correctly reported. I am expecting a device name to appear in /dev so the zip disk can be mounted but nothing happens. Have also tried Fsys.umass -n etc but not really sure of the “use” info and again no result. I would appreciate any comments.