/***********************************************************************/

/* File KSAUX.C - S4 Drivers for Nimbus Piconet; interface from
	Kermit calls to Mike Maloney standard interface for RS422 mode.
			Chris Kennington	1st July 1985	*/

/* All procedures in this file map down into calls to the functions
	described In Mike Maloney's "Nimbus Piconet interface
	specification" of 1st July 1985.
   422 mode uses piconet address 1fH.				*/

#define  PIC422	 0x1f

extern	int	p_break(), p_close(), p_flush(),  p_getc(),  p_open(),
		p_putc(),  p_speed(), p_status(), p_xonxoff();	/* MikeM procs	*/

static  int	status;
static  char	alive = 0;		/* initialized flag		*/
static  char	awake = 0;		/* awake flag			*/
static	char	parity = 0;
static	char	speed = 1;
static	int	picspeed[] = {110,300,600,1200,2400,4800,9600,19200,0};
	/* all valid speeds:	0   1	2    3	  4    5    6	  7   */
static  char  partab[] = {
/* character-parity table, 7-bit chars;	0 if even, 1 if odd.	*/
	0,1,1,0, 1,0,0,1,  1,0,0,1, 0,1,1,0,	/*  0-15, 00-0f	*/
	1,0,0,1, 0,1,1,0,  0,1,1,0, 1,0,0,1,	/* 16-31, 10-1f	*/
	1,0,0,1, 0,1,1,0,  0,1,1,0, 1,0,0,1,	/* 32-47, 20-2f	*/
	0,1,1,0, 1,0,0,1,  1,0,0,1, 0,1,1,0,	/* 48-63, 30-3f	*/
	1,0,0,1, 0,1,1,0,  0,1,1,0, 1,0,0,1,	/* 64-79, 40-4f	*/
	0,1,1,0, 1,0,0,1,  1,0,0,1, 0,1,1,0,	/* 80-95, 50-5f	*/
	0,1,1,0, 1,0,0,1,  1,0,0,1, 0,1,1,0,	/* 96-111, 60-6f */
	1,0,0,1, 0,1,1,0,  0,1,1,0, 1,0,0,1	/* 112-127, 70-7f */
	};				/* end of parity table	*/
	


char par(c,p)		/* return with parity			*/
/* strips to 7 bits, then adds correct parity; even if p=0, else odd	*/
char	c, p;
{
    char  b, d;

    c &= 0x7f;
    b = (partab[c] == 0) ? 0 : 0x80;
    if (p != 0)
	b ^= 0x80;
    d = b | c;
    return(d);
}			/* end of par()					*/



s4break(len)		/* send break - official		*/
char	len;
{
    int	  time;

    if ( (alive == 0) || (awake == 0) ) {
	printf(" not in contact ");
	return(-1);
    }
    time = len << 7;			/* sec/8 => msec	*/
    p_break(PIC422,time);
    outc(' ');
    return(0);
}			/* end of s4break()			*/


s4env()			/* return environment value		*/
/* Environment codes are:-
	0  -  480Z, via SIO4;		1  -  480Z, via IDC;
	2  -  Nimbus, via DCC;		3  -  Nimbus, via RS422 Aux;
	4  -  Nimbus, via Piconet SIM;
	5  -  either, via Network Comms Server (n.y.i.).
(see KDATA.C for texts used on bottom header)			*/
{
    return(3);
}			/* end of s4env()			*/


s4get(n,buff)		/* read some character, maybe		*/
char	n, *buff;
{
    awake = 1;
    if ( (p_getc(PIC422,buff)) != 0 )
	return(0);
    else
	return(1);
}			/* end of s4get()			*/


s4get7(n,buff)		/* read some 7-character, maybe		*/
char	n, *buff;
{
    awake = 1;
    if ( (p_getc(PIC422,buff)) != 0 )
	return(0);
    else {
	*buff &= 0x7f;
	return(1);
    }
}			/* end of s4get7()			*/


s4go()			/* fire up RS422 comms			*/
{
    int	   i;
    char   *addr;

    awake = 1;
    if (alive != 0)
	return(0);
    if ( (addr = malloc (1610)) == 0 ) {
	printf("\nNo store for comms.\n");
	kermkill(1);
    }
    else {
	if ( (i = p_open(PIC422,'I',1600,addr)) != 0 ) {
	    printf("\nCannot open comms, error-code %xx.\n",i);
	    kermkill(1);
	}
	alive = 1;
    }
    return(0);
}			/* end of s4go()			*/


s4put(n,buff)		/* send some chars			*/
char	n, *buff;
{
    char	c;

    awake = 1;
    c = *buff;
    switch(parity) {
      default:			/* 0 or > 3 (impossible)	*/
	break;
      case 1:			/* 1 = odd			*/
	c = par(c,1);
	break;
      case 2:			/* 2 = even			*/
	c = par(c,0);
	break;
      case 3:			/* 3 = mark			*/
	c |= 0x80;
	break;
    }			/* end switch				*/
    if (p_putc(PIC422,c) == 0)
	return(1);
    else
 	return(0);
}			/* end of s4put				*/


s4set(facil,wr5)	/* set facilities - dummy		*/
int	facil;
char	wr5;
{
    char	x;

    parity = (facil & 0x0300) >> 8;
    x = ( (facil & 0x0002) == 0 ) ? 0 : 0xff;
    p_xonxoff(PIC422,x);
    return(0);
}			/* end of s4set()			*/


s4sleep()		/* dummy deactivate			*/
{
    awake = 0;
    return(0);
}


s4speed(kspeed)		/* set line-speed			*/
char	kspeed;			/* 480Z speed-code		*/
{
    int	 i, spd;

    speed = kspeed;
    if (alive != 0) {
	spd = picspeed[kspeed];
	if ( (i = p_speed(PIC422,spd,spd)) != 0 ) {
	    printf("\nCannot set speed, error-code %xx.\n",i);
	    kermkill(1);
    }	}
    return(0);
}			/* end of s4speed()			*/


s4status()		/* return status-byte (in int)		*/
{
    return(p_status(PIC422));
}			/* end of s4status()			*/


s4stop()		/* close down communications		*/
{
    if (alive = 0)
	return(0);
    alive = awake = 0;
    p_close(PIC422);
    return(0);
}			/* end of s4stop()			*/



s4test()		/* return status - dummy		*/
{
    return(0);
}			/* end of s4test()			*/


/******************  END of file KSMIKE.C  *******************************/