Function            is2nd8259 - is a 2nd 8259 chip installed

  Syntax              int is2nd8259(void)

  Prototype in        ibm.h

  Remarks             is2nd8259() detects if a 2nd 8259 chip is
                      installed.

  Return value        returns 1 if a 2nd 8259 chip is installed, 0 if it
                      is not, and -1 if this function is not supported.

  Note                the 1/10/86 XT BIOS returns an incorrect value for
                      this function, so if the machine is an IBM XT or
                      compatible with a BIOS date of 1/10/86, do not use
                      this function.

  Example             #include <ibm.h>

                      main()
                      {
                           printf("2nd 8259 chip: ");
                           switch (is2nd8259()) {
                                case -1: printf("Error");  break;
                                case  0: printf("No");  break;
                                case  1: printf("Yes");  break;
                      }