Go find the software "Vol-FCR' - older versions can be found on the net. Couple that with a $10 Vag-Com cable, and you get full access to everything on your 850! (On mine, I can even query the power seats!).
Unfortunately, the software won't support OBDLink or ElmScan, but it's a cheap addition to get you everything on that vintage Volvo.
(Note that Vol-FCR appears to *NOT* support the more recent CAN bus based Volvos, just the older stuff . . . ).