Cool that the divider worked for you. I tried to assembly the cable to a HC-06 bluetooth modul, I have only 10k resistors at home right now, but it did not work with a 10k+10k to halve the voltage from the Virtuoso to 5.5V. The divider worked on the Beagleboard, but the HC-06 did not power up. I order a regulator to make the connection. I also built a normal cable (RJ11 to USB) which works fine.
After looking in the software options, I think to write an INDI driver for the Virtuoso because the ASCOM driver is Windows-only and I want to control my scope from my Raspberry Pi.