text: /* Global variables. */
  
  /* Parameters needed to keep diagnostics at IS. */
  #define DIAG_BUF_SIZE 1024
  extern char diag_buf[DIAG_BUF_SIZE];	/* buffer for messages */
  extern int diag_next;			/* next index to be written */
  extern int diag_size;			/* size of all messages */
  
  /* Flag to indicate system-wide panic. */
  extern int sys_panic;		/* if set, shutdown can be done */
  
  /* The parameters of the call are kept here. */
  extern message m_in;		/* the input message itself */
  extern message m_out;		/* the output message used for reply */
  extern int who;			/* caller's proc number */
  extern int callnr;		/* system call number */
  extern int dont_reply;		/* normally 0; set to 1 to inhibit reply */
  
  