diff --git a/PDP10/ka10_cart.c b/PDP10/ka10_cart.c
new file mode 100644
index 00000000..14952d37
--- /dev/null
+++ b/PDP10/ka10_cart.c
@@ -0,0 +1,168 @@
+/* ka10_cart.c: Stanford cart, with audiovisual system indicators.
+
+   Copyright (c) 2021, Lars Brinkhoff
+
+   Permission is hereby granted, free of charge, to any person obtaining a
+   copy of this software and associated documentation files (the "Software"),
+   to deal in the Software without restriction, including without limitation
+   the rights to use, copy, modify, merge, publish, distribute, sublicense,
+   and/or sell copies of the Software, and to permit persons to whom the
+   Software is furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+   LARS BRINKHOFF BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+   IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+   This is a device which interfaces with the Stanford cart.  It also
+   controls three lights and a solenoid to ring a bell.  It's specific
+   to the SAIL PDP-10.  The hardware interface is documented in the
+   UUO manual.
+*/
+
+#include "kx10_defs.h"
+
+#if NUM_DEVS_CART > 0
+
+#define CART_DEVNUM 0354
+
+/* CONO bits. */
+#define CART_UDP    0000001LL /* UDP in use. */
+#define CART_RED    0000004LL /* System crash. */
+#define CART_YEL    0000010LL /* System crash. */
+#define CART_TUN    0000720LL /* TV tuner. */
+#define CART_BEL    0001000LL /* System being debugged. */
+#define CART_DRV    0001000LL /* Cart drive direction. */
+#define CART_ON     0002000LL /* Cart drive on. */
+#define CART_STR    0004000LL /* Cart steer right. */
+#define CART_STL    0010000LL /* Cart steer left. */
+#define CART_PNR    0020000LL /* Cart pan right. */
+#define CART_PNL    0040000LL /* Cart pan left. */
+#define CART_MASK   0177777LL
+#define CART_GRN    0200000LL /* One-shot: system running. */
+#define CART_OFF    0400000LL
+
+/* Delay for one-shot action, in microseconds. */
+#define CART_ONESHOT  1000000
+
+/* Device state is 18 bits. */
+#define cart_bits cart_unit.u3
+
+static t_stat cart_devio(uint32 dev, uint64 *data);
+static t_stat cart_svc(UNIT *uptr);
+static t_stat cart_reset (DEVICE *dptr);
+static const char  *cart_description (DEVICE *dptr);
+
+DIB cart_dib = { CART_DEVNUM, 1, &cart_devio, NULL };
+
+UNIT cart_unit = {
+    UDATA (&cart_svc, UNIT_IDLE, 0)
+};
+
+REG cart_reg[] = {
+    {ORDATA(BITS, cart_bits, 18)},
+    {0}
+};
+
+DEVICE cart_dev = {
+    "CART", &cart_unit, cart_reg, NULL,
+    1, 8, 0, 1, 8, 36,
+    NULL, NULL, &cart_reset, NULL, NULL, NULL,
+    &cart_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG, 0, NULL,
+    NULL, NULL, NULL, NULL, NULL, &cart_description
+};
+
+void cart_on (uint64 bits)
+{
+    bits &= ~cart_bits;
+    cart_bits |= bits;
+    if (bits & CART_UDP)
+        sim_debug (DEBUG_CMD, &cart_dev, "UDP in use lamp on.");
+    if (bits & CART_RED)
+        sim_debug (DEBUG_CMD, &cart_dev, "Red lamp on.");
+    if (bits & CART_YEL)
+        sim_debug (DEBUG_CMD, &cart_dev, "Yellow lamp on.");
+    if (bits & CART_BEL)
+        sim_debug (DEBUG_CMD, &cart_dev, "Bell!");
+    if (bits & CART_GRN)
+        sim_debug (DEBUG_CMD, &cart_dev, "Green lamp on.");
+    if (bits & CART_TUN)
+        sim_debug (DEBUG_CMD, &cart_dev, "Frobbing TV tuner.");
+}
+
+void cart_off (uint64 bits)
+{
+    bits &= cart_bits;
+    cart_bits &= ~bits;
+    if (bits & CART_UDP)
+        sim_debug (DEBUG_CMD, &cart_dev, "UDP in use lamp off.");
+    if (bits & CART_RED)
+        sim_debug (DEBUG_CMD, &cart_dev, "Red lamp off.");
+    if (bits & CART_YEL)
+        sim_debug (DEBUG_CMD, &cart_dev, "Yellow lamp off.");
+    if (bits & CART_GRN)
+        sim_debug (DEBUG_CMD, &cart_dev, "Green lamp off.");
+    if (bits & CART_TUN)
+        sim_debug (DEBUG_CMD, &cart_dev, "Frobbing TV tuner.");
+}
+
+void cart_oneshot (void)
+{
+    /* This is a "one-shot" action. */
+    sim_debug(DEBUG_DETAIL, &cart_dev, "Trigger one shot.");
+    cart_on (CART_GRN);
+    cart_off (CART_GRN << 1);
+    sim_cancel (&cart_unit);
+    sim_activate_after (&cart_unit, CART_ONESHOT);
+}
+
+static t_stat cart_svc(UNIT *uptr)
+{
+    sim_debug(DEBUG_DETAIL, &cart_dev, "One shot expired.");
+    cart_off (CART_GRN);
+    cart_on (CART_GRN << 1);
+    return SCPE_OK;
+}
+
+t_stat cart_devio(uint32 dev, uint64 *data)
+{
+    uint64 bits;
+
+    switch(dev & 07) {
+    case CONO|4:
+        bits = *data;
+        sim_debug(DEBUG_CONO, &cart_dev, "%06llo", bits);
+        if (bits & CART_GRN)
+            cart_oneshot ();
+        bits &= CART_MASK;
+        if (*data & CART_OFF)
+            cart_off (bits);
+        else
+            cart_on (bits);
+        break;
+    case CONI|4:
+        *data = cart_bits & CART_MASK;
+        break;
+    /* This device doesn't respond to DATAI/O. */
+    }
+
+    return SCPE_OK;
+}
+
+static t_stat cart_reset (DEVICE *dptr)
+{
+    if (sim_switches & SWMASK('P'))
+        cart_bits = 0;
+    return SCPE_OK;
+}
+
+const char *cart_description (DEVICE *dptr)
+{
+    return "Stanford cart";
+}
+#endif
diff --git a/PDP10/kx10_defs.h b/PDP10/kx10_defs.h
index e6af98b4..0890be43 100644
--- a/PDP10/kx10_defs.h
+++ b/PDP10/kx10_defs.h
@@ -500,6 +500,7 @@ extern DEVICE   pd_dev;
 extern DEVICE   pclk_dev;
 extern DEVICE   dpy_dev;
 extern DEVICE   iii_dev;
+extern DEVICE   cart_dev;
 extern DEVICE   imx_dev;
 extern DEVICE   imp_dev;
 extern DEVICE   ch10_dev;
@@ -772,6 +773,7 @@ extern void ka10_lights_clear_aux (int);
 #define NUM_DEVS_DKB    (WAITS * USE_DISPLAY)
 #define NUM_DEVS_III    (WAITS * USE_DISPLAY)
 #define NUM_DEVS_TV     (WAITS * USE_DISPLAY)
+#define NUM_DEVS_CART   WAITS
 #define NUM_DEVS_PD     ITS
 #define NUM_DEVS_PCLK   WAITS
 #define NUM_DEVS_IMX    ITS
diff --git a/PDP10/kx10_sys.c b/PDP10/kx10_sys.c
index 64269957..2307171e 100644
--- a/PDP10/kx10_sys.c
+++ b/PDP10/kx10_sys.c
@@ -177,6 +177,9 @@ DEVICE *sim_devices[] = {
 #if (NUM_DEVS_TV > 0)
     &tv_dev,
 #endif
+#if (NUM_DEVS_CART > 0)
+    &cart_dev,
+#endif
 #if NUM_DEVS_IMP > 0
     &imp_dev,
 #endif
diff --git a/makefile b/makefile
index db664acc..23abb606 100644
--- a/makefile
+++ b/makefile
@@ -2118,7 +2118,7 @@ KA10 = ${KA10D}/kx10_cpu.c ${KA10D}/kx10_sys.c ${KA10D}/kx10_df.c \
 	${KA10D}/pdp6_dtc.c ${KA10D}/pdp6_mtc.c ${KA10D}/pdp6_dsk.c \
 	${KA10D}/pdp6_dcs.c ${KA10D}/ka10_dpk.c ${KA10D}/kx10_dpy.c \
 	${PDP10D}/ka10_ai.c ${KA10D}/ka10_iii.c ${KA10D}/kx10_disk.c \
-	${PDP10D}/ka10_pclk.c ${PDP10D}/ka10_tv.c \
+	${PDP10D}/ka10_pclk.c ${PDP10D}/ka10_tv.c ${PDP10D}/ka10_cart.c \
 	${DISPLAYL} ${DISPLAY340}
 KA10_OPT = -DKA=1 -DUSE_INT64 -I ${KA10D} -DUSE_SIM_CARD ${NETWORK_OPT} ${DISPLAY_OPT} ${KA10_DISPLAY_OPT}
 ifneq (${PANDA_LIGHTS},)