diff --git a/VAX/vax780_defs.h b/VAX/vax780_defs.h
index 9e170172..f47b8656 100644
--- a/VAX/vax780_defs.h
+++ b/VAX/vax780_defs.h
@@ -313,6 +313,8 @@ typedef struct {
 #define IOLN_PTR        004
 #define IOBA_PTP        (IOPAGEBASE + 017554)           /* PC11 punch */
 #define IOLN_PTP        004
+#define IOBA_DMC        (IOPAGEBASE + 0760060)
+#define IOLN_DMC        010
 
 /* Interrupt assignments; within each level, priority is right to left */
 
@@ -325,6 +327,8 @@ typedef struct {
 #define INT_V_TS        6
 #define INT_V_RY        7
 #define INT_V_XU        8
+#define INT_V_DMCRX     9
+#define INT_V_DMCTX     10
 
 #define INT_V_LPT       0                               /* BR4 */
 #define INT_V_PTR       1
@@ -348,6 +352,8 @@ typedef struct {
 #define INT_PTR         (1u << INT_V_PTR)
 #define INT_PTP         (1u << INT_V_PTP)
 #define INT_CR          (1u << INT_V_CR)
+#define INT_DMCRX       (1u << INT_V_DMCRX)
+#define INT_DMCTX       (1u << INT_V_DMCTX)
 
 #define IPL_DZRX        (0x15 - IPL_HMIN)
 #define IPL_DZTX        (0x15 - IPL_HMIN)
@@ -364,6 +370,8 @@ typedef struct {
 #define IPL_CR          (0x14 - IPL_HMIN)
 #define IPL_VHRX        (0x14 - IPL_HMIN)
 #define IPL_VHTX        (0x14 - IPL_HMIN)
+#define IPL_DMCRX       (0x15 - IPL_HMIN)
+#define IPL_DMCTX       (0x15 - IPL_HMIN)
 
 /* Device vectors */
 
@@ -386,6 +394,8 @@ typedef struct {
 #define VEC_DZTX        0304
 #define VEC_VHRX        0310
 #define VEC_VHTX        0314
+#define VEC_DMCRX       0310
+#define VEC_DMCTX       0314
 
 /* Interrupt macros */
 
diff --git a/VAX/vax780_syslist.c b/VAX/vax780_syslist.c
index 9025f616..8d179231 100644
--- a/VAX/vax780_syslist.c
+++ b/VAX/vax780_syslist.c
@@ -54,6 +54,8 @@ extern DEVICE tu_dev;
 extern DEVICE dz_dev;
 extern DEVICE vh_dev;
 extern DEVICE xu_dev, xub_dev;
+extern DEVICE dmc_dev[];
+extern DEVICE dmp_dev[];
 
 extern int32 sim_switches;
 extern UNIT cpu_unit;
@@ -91,6 +93,11 @@ DEVICE *sim_devices[] = {
     &tq_dev,
     &xu_dev,
     &xub_dev,
+	&dmc_dev[0],
+	&dmc_dev[1],
+	&dmc_dev[2],
+	&dmc_dev[3],
+	&dmp_dev[0],
     NULL
     };
 
diff --git a/Visual Studio Projects/VAX780.vcproj b/Visual Studio Projects/VAX780.vcproj
index d688ef3f..0c83a493 100644
--- a/Visual Studio Projects/VAX780.vcproj	
+++ b/Visual Studio Projects/VAX780.vcproj	
@@ -205,6 +205,10 @@
 				RelativePath="..\PDP11\pdp11_cr.c"
 				>
 			</File>
+			<File
+				RelativePath="..\PDP11\pdp11_dmc.c"
+				>
+			</File>
 			<File
 				RelativePath="..\PDP11\pdp11_dz.c"
 				>
@@ -387,6 +391,10 @@
 			Name="Header Files"
 			Filter="h;hpp;hxx;hm;inl;inc"
 			>
+			<File
+				RelativePath="..\PDP11\pdp11_dmc.h"
+				>
+			</File>
 			<File
 				RelativePath="..\PDP11\pdp11_io_lib.h"
 				>
diff --git a/makefile b/makefile
index d9a23ac5..562961ed 100644
--- a/makefile
+++ b/makefile
@@ -480,7 +480,7 @@ VAX780 = ${VAXD}/vax_cpu.c ${VAXD}/vax_cpu1.c ${VAXD}/vax_fpa.c \
 	${PDP11D}/pdp11_dz.c ${PDP11D}/pdp11_lp.c ${PDP11D}/pdp11_tq.c \
 	${PDP11D}/pdp11_xu.c ${PDP11D}/pdp11_ry.c ${PDP11D}/pdp11_cr.c \
 	${PDP11D}/pdp11_rp.c ${PDP11D}/pdp11_tu.c ${PDP11D}/pdp11_hk.c \
-	${PDP11D}/pdp11_vh.c ${PDP11D}/pdp11_io_lib.c
+	${PDP11D}/pdp11_vh.c ${PDP11D}/pdp11_dmc.c \${PDP11D}/pdp11_io_lib.c
 VAX780_OPT = -DVM_VAX -DVAX_780 -DUSE_INT64 -DUSE_ADDR64 -I VAX -I ${PDP11D} ${NETWORK_OPT}