diff --git a/usr.sbin/sicontrol/Makefile b/usr.sbin/sicontrol/Makefile
new file mode 100644
index 000000000000..48dab5812dfc
--- /dev/null
+++ b/usr.sbin/sicontrol/Makefile
@@ -0,0 +1,5 @@
+PROG=	sicontrol
+SRCS=	sicontrol.c
+MAN8=	sicontrol.8
+
+.include <bsd.prog.mk>
diff --git a/usr.sbin/sicontrol/sicontrol.c b/usr.sbin/sicontrol/sicontrol.c
new file mode 100644
index 000000000000..ff6bdd410134
--- /dev/null
+++ b/usr.sbin/sicontrol/sicontrol.c
@@ -0,0 +1,584 @@
+/*
+ * Device driver for Specialix range (SLXOS) of serial line multiplexors.
+ *	SLXOS configuration and debug interface
+ *
+ * Copyright (C) 1990, 1992 Specialix International,
+ * Copyright (C) 1993, Andy Rutter <andy@acronym.co.uk>
+ * Copyright (C) 1995, Peter Wemm <peter@haywire.dialix.com>
+ *
+ * Derived from:	SunOS 4.x version
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notices, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notices, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by Andy Rutter of
+ *	Advanced Methods and Tools Ltd. based on original information
+ *	from Specialix International.
+ * 4. Neither the name of Advanced Methods and Tools, nor Specialix
+ *    International may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL THE AUTHORS BE LIABLE.
+ *
+ *	$Id$
+ */
+
+#include <stdio.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/device.h>
+#include <sys/tty.h>
+#include <fcntl.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <machine/si.h>
+
+struct lv {
+	char	*lv_name;
+	int 	lv_bit;
+} lv[] = {
+	"entry",	DBG_ENTRY,
+	"open",		DBG_OPEN,
+	"close",	DBG_CLOSE,
+	"read",		DBG_READ,
+	"write",	DBG_WRITE,
+	"param",	DBG_PARAM,
+	"modem",	DBG_MODEM,
+	"select",	DBG_SELECT,
+	"direct",	DBG_DIRECT,
+	"intr",		DBG_INTR,
+	"start",	DBG_START,
+	"lstart",	DBG_LSTART,
+	"ioctl",	DBG_IOCTL,
+	"fail",		DBG_FAIL,
+	"autoboot",	DBG_AUTOBOOT,
+	"download",	DBG_DOWNLOAD,
+	"drain",	DBG_DRAIN,
+	"poll",		DBG_POLL,
+	0,		0
+};
+
+static int alldev = 0;
+int getnum(char *str);
+
+int debug(), rxint(), txint();
+int mstate(), nport();
+int ccb_stat(), tty_stat();
+struct opt {
+	char	*o_name;
+	int	(*o_func)();
+} opt[] = {
+	"debug",		debug,
+	"rxint_throttle",	rxint,
+	"int_throttle",		txint,
+	"mstate",		mstate,
+	"nport",		nport,
+	"ccbstat",		ccb_stat,
+	"ttystat",		tty_stat,
+	0,			0,
+};
+
+struct stat_list {
+	int (*st_func)();
+} stat_list[] = {
+	mstate,
+	0
+};
+
+#define	U_DEBUG		0
+#define	U_TXINT		1
+#define	U_RXINT		2
+#define	U_MSTATE	3
+#define	U_NPORT		4
+#define	U_STAT_CCB	5
+#define	U_STAT_TTY	6
+#define	U_STAT_PORT	7
+
+#define	U_MAX		7
+#define	U_ALL		-1
+char *usage[] = {
+	"debug [[add|del|set debug_levels] | [off]]\n",
+	"int_throttle [newvalue]\n",
+	"rxint_throttle [newvalue]\n",
+	"mstate\n",
+	"nport\n",
+	"ccbstat\n",
+	"ttystat\n",
+	"portstat\n",
+	0
+};
+
+int ctlfd;
+char *Devname;
+struct si_tcsi tc;
+
+main(argc, argv)
+	char **argv;
+{
+	struct opt *op;
+	int (*func)() = NULL;
+
+	if (argc < 2)
+		prusage(U_ALL, 1);
+	Devname = argv[1];
+	if (strcmp(Devname, "-") == 0) {
+		alldev = 1;
+	} else {
+		sidev_t dev;
+		struct stat st;
+
+		if (strchr(Devname, '/') == NULL) {
+			char *acp = malloc(6 + strlen(Devname));
+			strcpy(acp, "/dev/");
+			strcat(acp, Devname);
+			Devname = acp;
+		}
+		if (stat(Devname, &st) < 0) {
+			fprintf(stderr, "can't stat %s\n", Devname);
+			exit(1);
+		}
+		dev.sid_card = SI_CARD(minor(st.st_rdev));
+		dev.sid_port = SI_PORT(minor(st.st_rdev));
+		tc.tc_dev = dev;
+	}
+	ctlfd = opencontrol();
+	if (argc == 2) {
+		dostat();
+		exit(0);
+	}
+
+	argc--; argv++;
+	for (op = opt; op->o_name; op++) {
+		if (strcmp(argv[1], op->o_name) == 0) {
+			func = op->o_func;
+			break;
+		}
+	}
+	if (func == NULL)
+		prusage(U_ALL, 1);
+
+	argc -= 2;
+	argv += 2;
+	(*func)(argc, argv);
+	exit(0);
+}
+
+opencontrol()
+{
+	int fd;
+
+	fd = open(CONTROLDEV, O_RDWR|O_NDELAY);
+	if (fd < 0) {
+		fprintf(stderr, "open on %s - ", CONTROLDEV);
+		perror("");
+		exit(1);
+	}
+	return(fd);
+}
+
+/*
+ * Print a usage message - this relies on U_DEBUG==0 and U_BOOT==1.
+ * Don't print the DEBUG usage string unless explicity requested.
+ */
+prusage(strn, eflag)
+	int strn, eflag;
+{
+	char **cp;
+
+	if (strn == U_ALL) {
+		fprintf(stderr, "Usage: siconfig - %s", usage[1]);
+		fprintf(stderr, "       siconfig devname %s", usage[2]);
+		for (cp = &usage[3]; *cp; cp++)
+			fprintf(stderr, "                        %s", *cp);
+	}
+	else if (strn >= 0 && strn <= U_MAX)
+		fprintf(stderr, "Usage: siconfig devname %s", usage[strn]);
+	else
+		fprintf(stderr, "siconfig: usage ???\n");
+	exit(eflag);
+}
+
+/* print port status */
+dostat()
+{
+	char *av[1], *acp;
+	struct stat_list *stp;
+	struct si_tcsi stc;
+	int (*func)();
+	int donefirst = 0;
+
+	printf("%s: ", alldev ? "ALL" : Devname);
+	acp = malloc(strlen(Devname) + 3);
+	memset(acp, ' ', strlen(Devname));
+	strcat(acp, "  ");
+	stc = tc;
+	for (stp = stat_list; stp->st_func != NULL; stp++) {
+		if (donefirst)
+			fputs(acp, stdout);
+		else
+			donefirst++;
+		av[0] = NULL;
+		tc = stc;
+		(*stp->st_func)(-1, av);
+	}
+}
+
+/*
+ * debug
+ * debug [[set|add|del debug_lvls] | [off]]
+ */
+debug(ac, av)
+	char **av;
+{
+	int level, cmd;
+	char *str;
+
+	if (ac > 2)
+		prusage(U_DEBUG, 1);
+	if (alldev) {
+		if (ioctl(ctlfd, TCSIGDBG_ALL, &tc.tc_dbglvl) < 0)
+			Perror("TCSIGDBG_ALL on %s", Devname);
+	} else {
+		if (ioctl(ctlfd, TCSIGDBG_LEVEL, &tc) < 0)
+			Perror("TCSIGDBG_LEVEL on %s", Devname);
+	}
+
+	switch (ac) {
+	case 0:
+		printf("%s: debug levels - ", Devname);
+		prlevels(tc.tc_dbglvl);
+		return;
+	case 1:
+		if (strcmp(av[0], "off") == 0) {
+			tc.tc_dbglvl = 0;
+			break;
+		}
+		prusage(U_DEBUG, 1);
+		/* no return */
+	case 2:
+		level = lvls2bits(av[1]);
+		if (strcmp(av[0], "add") == 0)
+			tc.tc_dbglvl |= level;
+		else if (strcmp(av[0], "del") == 0)
+			tc.tc_dbglvl &= ~level;
+		else if (strcmp(av[0], "set") == 0)
+			tc.tc_dbglvl = level;
+		else
+			prusage(U_DEBUG, 1);
+	}
+	if (alldev) {
+		if (ioctl(ctlfd, TCSISDBG_ALL, &tc.tc_dbglvl) < 0)
+			Perror("TCSISDBG_ALL on %s", Devname);
+	} else {
+		if (ioctl(ctlfd, TCSISDBG_LEVEL, &tc) < 0)
+			Perror("TCSISDBG_LEVEL on %s", Devname);
+	}
+}
+
+rxint(ac, av)
+	char **av;
+{
+	tc.tc_port = 0;
+	switch (ac) {
+	case 0:
+		printf("%s: ", Devname);
+	case -1:
+		if (ioctl(ctlfd, TCSIGRXIT, &tc) < 0)
+			Perror("TCSIGRXIT");
+		printf("RX interrupt throttle: %d msec\n", tc.tc_int*10);
+		break;
+	case 1:
+		tc.tc_int = getnum(av[0]) / 10;
+		if (tc.tc_int == 0)
+			tc.tc_int = 1;
+		if (ioctl(ctlfd, TCSIRXIT, &tc) < 0)
+			Perror("TCSIRXIT on %s at %d msec", Devname, tc.tc_int*10);
+		break;
+	default:
+		prusage(U_RXINT, 1);
+	}
+}
+
+txint(ac, av)
+	char **av;
+{
+
+	tc.tc_port = 0;
+	switch (ac) {
+	case 0:
+		printf("%s: ", Devname);
+	case -1:
+		if (ioctl(ctlfd, TCSIGIT, &tc) < 0)
+			Perror("TCSIGIT");
+		printf("aggregate interrupt throttle: %d\n", tc.tc_int);
+		break;
+	case 1:
+		tc.tc_int = getnum(av[0]);
+		if (ioctl(ctlfd, TCSIIT, &tc) < 0)
+			Perror("TCSIIT on %s at %d", Devname, tc.tc_int);
+		break;
+	default:
+		prusage(U_TXINT, 1);
+	}
+}
+
+onoff(ac, av, cmd, cmdstr, prstr, usage)
+	char **av, *cmdstr, *prstr;
+	int ac, cmd, usage;
+{
+	if (ac > 1)
+		prusage(usage, 1);
+	if (ac == 1) {
+		if (strcmp(av[0], "on") == 0)
+			tc.tc_int = 1;
+		else if (strcmp(av[0], "off") == 0)
+			tc.tc_int = 0;
+		else
+			prusage(usage, 1);
+	} else
+		tc.tc_int = -1;
+	if (ioctl(ctlfd, cmd, &tc) < 0)
+		Perror("%s on %s", cmdstr, Devname);
+	switch (ac) {
+	case 0:
+		printf("%s: ", Devname);
+	case -1:
+		printf("%s ", prstr);
+		if (tc.tc_int)
+			printf("on\n");
+		else
+			printf("off\n");
+	}
+}
+
+mstate(ac, av)
+	char **av;
+{
+	u_char state;
+
+	switch (ac) {
+	case 0:
+		printf("%s: ", Devname);
+	case -1:
+		break;
+	default:
+		prusage(U_MSTATE, 1);
+	}
+	if (ioctl(ctlfd, TCSISTATE, &tc) < 0)
+		Perror("TCSISTATE on %s", Devname);
+	printf("modem bits state - (0x%x)", tc.tc_int);
+	if (tc.tc_int & IP_DCD)	printf(" DCD");
+	if (tc.tc_int & IP_DTR)	printf(" DTR");
+	if (tc.tc_int & IP_RTS)	printf(" RTS");
+	printf("\n");
+}
+
+nport(ac, av)
+	char **av;
+{
+	int ports;
+
+	if (ac != 0)
+		prusage(U_NPORT, 1);
+	if (ioctl(ctlfd, TCSIPORTS, &ports) < 0)
+		Perror("TCSIPORTS on %s", Devname);
+	printf("SLXOS: total of %d ports\n", ports);
+}
+
+ccb_stat(ac, av)
+char **av;
+{
+	struct si_pstat sip;
+#define	CCB	sip.tc_ccb
+
+	if (ac != 0)
+		prusage(U_STAT_CCB);
+	sip.tc_dev = tc.tc_dev;
+	if (ioctl(ctlfd, TCSI_CCB, &sip) < 0)
+		Perror("TCSI_CCB on %s", Devname);
+	printf("%s: ", Devname);
+
+							/* WORD	next - Next Channel */
+							/* WORD	addr_uart - Uart address */
+							/* WORD	module - address of module struct */
+	printf("\tuart_type 0x%x\n", CCB.type);		/* BYTE type - Uart type */
+							/* BYTE	fill - */
+	printf("\tx_status 0x%x\n", CCB.x_status);	/* BYTE	x_status - XON / XOFF status */
+	printf("\tc_status 0x%x\n", CCB.c_status);	/* BYTE	c_status - cooking status */
+	printf("\thi_rxipos 0x%x\n", CCB.hi_rxipos);	/* BYTE	hi_rxipos - stuff into rx buff */
+	printf("\thi_rxopos 0x%x\n", CCB.hi_rxopos);	/* BYTE	hi_rxopos - stuff out of rx buffer */
+	printf("\thi_txopos 0x%x\n", CCB.hi_txopos);	/* BYTE	hi_txopos - Stuff into tx ptr */
+	printf("\thi_txipos 0x%x\n", CCB.hi_txipos);	/* BYTE	hi_txipos - ditto out */
+	printf("\thi_stat 0x%x\n", CCB.hi_stat);		/* BYTE	hi_stat - Command register */
+	printf("\tdsr_bit 0x%x\n", CCB.dsr_bit);		/* BYTE	dsr_bit - Magic bit for DSR */
+	printf("\ttxon 0x%x\n", CCB.txon);		/* BYTE	txon - TX XON char */
+	printf("\ttxoff 0x%x\n", CCB.txoff);		/* BYTE	txoff - ditto XOFF */
+	printf("\trxon 0x%x\n", CCB.rxon);		/* BYTE	rxon - RX XON char */
+	printf("\trxoff 0x%x\n", CCB.rxoff);		/* BYTE	rxoff - ditto XOFF */
+	printf("\thi_mr1 0x%x\n", CCB.hi_mr1);		/* BYTE	hi_mr1 - mode 1 image */
+	printf("\thi_mr2 0x%x\n", CCB.hi_mr2);		/* BYTE	hi_mr2 - mode 2 image */
+        printf("\thi_csr 0x%x\n", CCB.hi_csr);		/* BYTE	hi_csr - clock register */
+	printf("\thi_op 0x%x\n", CCB.hi_op);		/* BYTE	hi_op - Op control */
+	printf("\thi_ip 0x%x\n", CCB.hi_ip);		/* BYTE	hi_ip - Input pins */
+	printf("\thi_state 0x%x\n", CCB.hi_state);	/* BYTE	hi_state - status */
+	printf("\thi_prtcl 0x%x\n", CCB.hi_prtcl);	/* BYTE	hi_prtcl - Protocol */
+	printf("\thi_txon 0x%x\n", CCB.hi_txon);		/* BYTE	hi_txon - host copy tx xon stuff */
+	printf("\thi_txoff 0x%x\n", CCB.hi_txoff);	/* BYTE	hi_txoff - */
+	printf("\thi_rxon 0x%x\n", CCB.hi_rxon);		/* BYTE	hi_rxon - */
+	printf("\thi_rxoff 0x%x\n", CCB.hi_rxoff);	/* BYTE	hi_rxoff - */
+	printf("\tclose_prev 0x%x\n", CCB.close_prev);	/* BYTE	close_prev - Was channel previously closed */
+	printf("\thi_break 0x%x\n", CCB.hi_break);	/* BYTE	hi_break - host copy break process */
+	printf("\tbreak_state 0x%x\n", CCB.break_state);	/* BYTE	break_state - local copy ditto */
+	printf("\thi_mask 0x%x\n", CCB.hi_mask);		/* BYTE	hi_mask - Mask for CS7 etc. */
+	printf("\tmask_z280 0x%x\n", CCB.mask_z280);	/* BYTE	mask_z280 - Z280's copy */
+							/* BYTE	res[0x60 - 36] - */
+							/* BYTE	hi_txbuf[SLXOS_BUFFERSIZE] - */
+							/* BYTE	hi_rxbuf[SLXOS_BUFFERSIZE] - */
+							/* BYTE	res1[0xA0] - */
+
+}
+
+tty_stat(ac, av)
+char **av;
+{
+	struct si_pstat sip;
+#define	TTY	sip.tc_tty
+
+	if (ac != 0)
+		prusage(U_STAT_TTY);
+	sip.tc_dev = tc.tc_dev;
+	if (ioctl(ctlfd, TCSI_TTY, &sip) < 0)
+		Perror("TCSI_TTY on %s", Devname);
+	printf("%s: ", Devname);
+
+	printf("\tt_outq.c_cc %d.\n", TTY.t_outq.c_cc);	/* struct clist t_outq */
+	printf("\tt_dev 0x%x\n", TTY.t_dev);		/* dev_t t_dev */
+	printf("\tt_flags 0x%x\n", TTY.t_flags);	/* int	t_flags */
+	printf("\tt_state 0x%x\n", TTY.t_state);	/* int	t_state */
+	printf("\tt_hiwat %d.\n", TTY.t_hiwat);		/* short t_hiwat */
+	printf("\tt_lowat %d.\n", TTY.t_lowat);		/* short t_lowat */
+	printf("\tt_iflag 0x%x\n", TTY.t_iflag);	/* t_iflag */
+	printf("\tt_oflag 0x%x\n", TTY.t_oflag);	/* t_oflag */
+	printf("\tt_cflag 0x%x\n", TTY.t_cflag);	/* t_cflag */
+	printf("\tt_lflag 0x%x\n", TTY.t_lflag);	/* t_lflag */
+	printf("\tt_cc 0x%x\n", TTY.t_cc);		/* t_cc */
+	printf("\tt_termios.c_ispeed 0x%x\n", TTY.t_termios.c_ispeed);	/* t_termios.c_ispeed */
+	printf("\tt_termios.c_ospeed 0x%x\n", TTY.t_termios.c_ospeed);	/* t_termios.c_ospeed */
+
+}
+
+islevel(tk)
+	char *tk;
+{
+	register struct lv *lvp;
+	register char *acp;
+
+	for (acp = tk; *acp; acp++)
+		if (isupper(*acp))
+			*acp = tolower(*acp);
+	for (lvp = lv; lvp->lv_name; lvp++)
+		if (strcmp(lvp->lv_name, tk) == 0)
+			return(lvp->lv_bit);
+	return(0);
+}
+
+/*
+ * Convert a string consisting of tokens separated by white space, commas
+ * or `|' into a bitfield - flag any unrecognised tokens.
+ */
+lvls2bits(str)
+	char *str;
+{
+	int i, bits = 0;
+	int errflag = 0;
+	char token[20];
+
+	while (sscanf(str, "%[^,| \t]", token) == 1) {
+		str += strlen(token);
+		while (isspace(*str) || *str==',' || *str=='|')
+			str++;
+		if (strcmp(token, "all") == 0)
+			return(0xffffffff);
+		if ((i = islevel(token)) == 0) {
+			fprintf(stderr, "siconfig: unknown token '%s'\n", token);
+			errflag++;
+		} else
+			bits |= i;
+	}
+	if (errflag)
+		exit(1);
+
+	return(bits);
+}
+
+int
+getnum(char *str)
+{
+	int x;
+	register char *acp = str;
+
+	x = 0;
+	while (*acp) {
+		if (!isdigit(*acp)) {
+			error("%s is not a number\n", str);
+			exit(1);
+		}
+		x *= 10;
+		x += (*acp - '0');
+		acp++;
+	}
+	return(x);
+}
+
+prlevels(x)
+	int x;
+{
+	struct lv *lvp;
+
+	switch (x) {
+	case 0:
+		printf("(none)\n");
+		break;
+	case 0xffffffff:
+		printf("all\n");
+		break;
+	default:
+		for (lvp = lv; lvp->lv_name; lvp++)
+			if (x & lvp->lv_bit)
+				printf(" %s", lvp->lv_name);
+		printf("\n");
+	}
+}
+
+/* VARARGS */
+Perror(str, a1, a2, a3, a4, a5)
+	char *str;
+	int a1, a2, a3, a4, a5;
+{
+	fprintf(stderr, str, a1, a2, a3, a4, a5);
+	perror(" ");
+	exit(1);
+}
+
+/* VARARGS */
+error(str, a1, a2, a3, a4, a5)
+	char *str;
+	int a1, a2, a3, a4, a5;
+{
+	fprintf(stderr, str, a1, a2, a3, a4, a5);
+	exit(1);
+}