The RT Systems USB-64 USB programming cable has a DB9 pin serial plug at one end and a USB plug at the other.
This cable is USB 2.0 compliant. It comes with a Windows XP, Vista, 7 [32/64] and 8/8.1 driver CD (but not programming software).
This cable may be used for these Ten-Tec models:
Jupiter 538, 538CE, 538AT
Omni VII 588, 588AT
Orion 565, 565AT
Orion II 566, 566AT
RX-320D, RX-400