Startechcom usb adaptor cables startechcom icusb232sm3 this icusb232sm3 3ft usb to serial adaptor cable from startechcom lets you connect db9 rs232 serial devices to your laptop or desktop computer through an available usb port as though the computer offered an onboard db9m connectorunlike typical usb to serial converter cables where the conversion takes place at the db9 end the icusb232sm3 features a converter chip on the usb end converting at the usb source overcomes the 15ft technic