DosDevConfig

#define INCL_DOSDEVICES

USHORT  rc = DosDevConfig(DeviceInfo, Item, Parm);

PVOID            DeviceInfo;    /* Returned information */
USHORT           Item;          /* Item number */
USHORT           Parm;          /* Reserved */

USHORT           rc;            /* return */

Example 

This example gets information about model type, monitor and coprocessor 
and display it. 

#define INCL_DOSDEVICES

#define MACHINE_MODEL 5
#define DISPLAY_TYPE 6
#define FIND_COPROCESSOR 3
#define RESERVED 0L

BYTE   DeviceInfo;
USHORT rc;

   if(!DosDevConfig(&DeviceInfo,            /* Returned information */
                    MACHINE_MODEL,          /* Item number */
                    RESERVED))              /* Reserved */
      printf("Model Type %d ",DeviceInfo);

   if(!DosDevConfig(&DeviceInfo,            /* Returned information */
                    DISPLAY_TYPE,           /* Item number */
                    RESERVED))              /* Reserved */
      if (DeviceInfo)
         printf("Color display ");
      else
         printf("Mono display ");

   if(!DosDevConfig(&DeviceInfo,            /* Returned information */
                    FIND_COPROCESSOR,       /* Item number */
                    RESERVED))              /* Reserved */
      if (DeviceInfo)
         printf("Coprocessor");
      else
         printf("No Coprocessor");