diff --git a/aucat/aucat.1 b/aucat/aucat.1
index 446311d..94b658e 100644
--- a/aucat/aucat.1
+++ b/aucat/aucat.1
@@ -27,10 +27,12 @@
 .Op Fl c Ar min : Ns Ar max
 .Op Fl e Ar enc
 .Op Fl f Ar device
+.Op Fl g Ar position
 .Op Fl h Ar fmt
 .Op Fl i Ar file
 .Op Fl j Ar flag
 .Op Fl o Ar file
+.Op Fl p Ar position
 .Op Fl q Ar port
 .Op Fl r Ar rate
 .Op Fl v Ar volume
@@ -117,6 +119,10 @@ audio device.
 Device mode and parameters are determined from audio files.
 Default is
 .Pa default .
+.It Fl g Ar position
+Go to the given time position and start playback or recording there.
+This option is equivalent to an incoming MMC relocate message
+with the same position.
 .It Fl h Ar fmt
 Audio file type.
 The following file types are supported:
@@ -169,6 +175,10 @@ Record into this audio file.
 If the option argument is
 .Sq -
 then standard output will be used.
+.It Fl p Ar position
+Time offset where the beginning of the file belongs.
+The first sample of the file will be played or recorded when the current
+position reaches the given postion.
 .It Fl q Ar port
 Control audio device properties through this MIDI port.
 This includes per-stream volumes and the ability to
diff --git a/aucat/aucat.c b/aucat/aucat.c
index 308bcef..7a5e2f6 100644
--- a/aucat/aucat.c
+++ b/aucat/aucat.c
@@ -103,7 +103,7 @@ unsigned int dev_round;			/* device block size */
 int dev_rate;				/* device sample rate (Hz) */
 unsigned int dev_pchan, dev_rchan;	/* play & rec channels count */
 adata_t *dev_pbuf, *dev_rbuf;		/* play & rec buffers */
-long long dev_pos;			/* last MMC position in frames */
+unsigned int dev_mmcpos;		/* last MMC position */
 #define DEV_STOP	0		/* stopped */
 #define DEV_START	1		/* started */
 unsigned int dev_pstate;		/* one of above */
@@ -351,8 +351,10 @@ slot_init(struct slot *s)
 }
 
 static void
-slot_start(struct slot *s, long long pos)
+slot_start(struct slot *s, unsigned int mmc)
 {
+	off_t mmcpos;
+
 #ifdef DEBUG
 	if (s->pstate != SLOT_INIT) {
 		slot_log(s);
@@ -360,15 +362,8 @@ slot_start(struct slot *s, long long pos)
 		panic();
 	}
 #endif
-	/*
-	 * convert pos to slot sample rate
-	 *
-	 * At this stage, we could adjust s->resamp.diff to get
-	 * sub-frame accuracy.
-	 */
-	pos = pos * s->afile.rate / dev_rate;
-
-	if (!afile_seek(&s->afile, pos * s->bpf)) {
+	mmcpos = ((off_t)mmc * s->afile.rate / MTC_SEC) * s->bpf;
+	if (!afile_seek(&s->afile, mmcpos)) {
 		s->pstate = SLOT_INIT;
 		return;
 	}
@@ -667,7 +662,7 @@ dev_open(char *dev, int mode, int bufsz, char *port)
 		dev_rchan = par.rchan;
 		dev_rbuf = xmalloc(sizeof(adata_t) * dev_rchan * dev_round);
 	}
-	dev_pos = 0;
+	dev_mmcpos = 0;
 	dev_pstate = DEV_STOP;
 	if (log_level >= 2) {
 		log_puts(dev_name);
@@ -758,7 +753,7 @@ dev_mmcstart(void)
 	if (dev_pstate == DEV_STOP) {
 		dev_pstate = DEV_START;
 		for (s = slot_list; s != NULL; s = s->next)
-			slot_start(s, dev_pos);
+			slot_start(s, dev_mmcpos);
 		dev_prime = (dev_mode & SIO_PLAY) ? dev_bufsz / dev_round : 0;
 		sio_start(dev_sh);
 		if (log_level >= 2)
@@ -798,35 +793,20 @@ dev_mmcstop(void)
  * relocate all slots simultaneously
  */
 static void
-dev_mmcloc(int hr, int min, int sec, int fr, int cent, int fps)
+dev_mmcloc(unsigned int mmc)
 {
-	long long pos;
-
-	pos = dev_rate * hr * 3600 +
-	    dev_rate * min * 60 +
-	    dev_rate * sec +
-	    dev_rate * fr / fps +
-	    dev_rate * cent / (100 * fps);
-	if (dev_pos == pos)
+	if (dev_mmcpos == mmc)
 		return;
-	dev_pos = pos;
+	dev_mmcpos = mmc;
 	if (log_level >= 2) {
 		log_puts("relocated to ");
-		log_putu(hr);
+		log_putu((dev_mmcpos / (MTC_SEC * 3600)) % 24);
 		log_puts(":");
-		log_putu(min);
+		log_putu((dev_mmcpos / (MTC_SEC * 60)) % 60);
 		log_puts(":");
-		log_putu(sec);
+		log_putu((dev_mmcpos / (MTC_SEC)) % 60);
 		log_puts(".");
-		log_putu(fr);
-		log_puts(".");
-		log_putu(cent);
-		log_puts(" at ");
-		log_putu(fps);
-		log_puts("fps\n");
-
-		log_puts("pos: ");
-		log_putu(pos);
+		log_putu((dev_mmcpos / (MTC_SEC / 100)) % 100);
 		log_puts("\n");
 	}
 	if (dev_pstate == DEV_START) {
@@ -890,12 +870,11 @@ dev_imsg(unsigned char *msg, unsigned int len)
 			dev_mmcstop();
 			return;
 		}
-		dev_mmcloc(x->u.loc.hr & 0x1f,
-		    x->u.loc.min,
-		    x->u.loc.sec,
-		    x->u.loc.fr,
-		    x->u.loc.cent,
-		    fps);
+		dev_mmcloc((x->u.loc.hr & 0x1f) * 3600 * MTC_SEC +
+		    x->u.loc.min * 60 * MTC_SEC +
+		    x->u.loc.sec * MTC_SEC +
+		    x->u.loc.fr * (MTC_SEC / fps) +
+		    x->u.loc.cent * (MTC_SEC / 100 / fps));
 		break;
 	}
 }
@@ -1031,7 +1010,7 @@ offline(void)
 	dev_pchan = dev_rchan = cmax + 1;
 	dev_pbuf = dev_rbuf = xmalloc(sizeof(adata_t) * dev_pchan * dev_round);
 	dev_pstate = DEV_STOP;
-	dev_pos = 0;
+	dev_mmcpos = 0;
 	for (s = slot_list; s != NULL; s = s->next)
 		slot_init(s);
 	for (s = slot_list; s != NULL; s = s->next)
diff --git a/aucat/defs.h b/aucat/defs.h
index 6cfc877..0820cf5 100644
--- a/aucat/defs.h
+++ b/aucat/defs.h
@@ -17,6 +17,11 @@
 #ifndef DEFS_H
 #define DEFS_H
 
+/*
+ * units used for MTC clock.
+ */
+#define MTC_SEC			2400	/* 1 second is 2400 ticks */
+
 /*
  * limits
  */