How can I tell if I have a single-function or multi-function card?

The firmware version information contains single- and multi-function indications. Example "tstcfg.c" shows this value on the screen, and you can get this value by calling BusTools_GetRevision(). The Firmware revision contains the PROM version, single-function flag and the firmware version. The two version numbers you have show:

 PROM       Single       firmware 
Version  function flag   version 
  3           1            321     - PROM version 3,
                                     single-function,
                                     firmware revision 3.21
  4           0            321     - PROM version 4, 
                                     multi-function,
                                     firmware revision 3.21

If you attempt to run more than a single function (BC, BM, or RT) you will get a API_SINGLE_FUNCTION_ERR (231) error, "You have attempted to start multiple functions on a single function board".