diff --git a/PDP11/pdp11_defs.h b/PDP11/pdp11_defs.h
index bf79a4f7..bfa0e01b 100644
--- a/PDP11/pdp11_defs.h
+++ b/PDP11/pdp11_defs.h
@@ -518,6 +518,8 @@ typedef struct pdp_dib DIB;
 
 /* I/O page layout - XUB, RQB,RQC,RQD float based on number of DZ's */
 
+#define IOBA_FLOAT      (0)                             /* Assigned by Auto Configure */
+
 #define IOBA_DZ         (IOPAGEBASE + 000100)           /* DZ11 */
 #define IOLN_DZ         010
 #define IOBA_XUB        (IOPAGEBASE + 000330 + (020 * (DZ_MUXES / 2)))
@@ -528,8 +530,6 @@ typedef struct pdp_dib DIB;
 #define IOLN_RQC        004
 #define IOBA_RQD        (IOPAGEBASE + IOBA_RQC + IOLN_RQC)
 #define IOLN_RQD        004
-#define IOBA_VH         (IOPAGEBASE + 000440)           /* DHQ11 */
-#define IOLN_VH         020
 #define IOBA_UBM        (IOPAGEBASE + 010200)           /* Unibus map */
 #define IOLN_UBM        (UBM_LNT_LW * sizeof (int32))
 #define	IOBA_KG         (IOPAGEBASE + 010700)           /* KG11-A */
@@ -780,6 +780,8 @@ typedef struct pdp_dib DIB;
 
 /* Device vectors */
 
+#define VEC_FLOAT       (0)                             /* Assigned by Auto Configure */
+
 #define VEC_Q           0000                            /* vector base */
 #define VEC_PIRQ        0240
 #define VEC_TTI         0060
@@ -813,8 +815,6 @@ typedef struct pdp_dib DIB;
 #define VEC_DCO         0304
 #define VEC_DZRX        0300
 #define VEC_DZTX        0304
-#define VEC_VHRX        0310
-#define VEC_VHTX        0314
 
 /* Interrupt macros */
 
diff --git a/PDP11/pdp11_vh.c b/PDP11/pdp11_vh.c
index 23722268..c193cbe0 100644
--- a/PDP11/pdp11_vh.c
+++ b/PDP11/pdp11_vh.c
@@ -341,15 +341,16 @@ static t_stat vh_set_nolog (UNIT *uptr, int32 val, char *cptr, void *desc);
 static t_stat vh_show_log (FILE *st, UNIT *uptr, int32 val, void *desc);
 
 /* SIMH I/O Structures */
+#define IOLN_VH         020
 
 static DIB vh_dib = {
-    IOBA_VH,
+    IOBA_FLOAT,
     IOLN_VH * VH_MUXES,
     &vh_rd,     /* read */
     &vh_wr,     /* write */
     2,          /* # of vectors */
     IVCL (VHRX),
-    VEC_VHRX,
+    VEC_FLOAT,
     { &vh_rxinta, &vh_txinta }  /* int. ack. routines */
 };
 
diff --git a/VAX/vax610_defs.h b/VAX/vax610_defs.h
index 01609c81..d90b9f83 100644
--- a/VAX/vax610_defs.h
+++ b/VAX/vax610_defs.h
@@ -190,6 +190,8 @@ typedef struct {
 
 /* I/O page layout - RQB,RQC,RQD float based on number of DZ's */
 
+#define IOBA_FLOAT      (0)                             /* Assigned by Auto Configure */
+
 #define IOBA_DZ         (IOPAGEBASE + 000100)           /* DZ11 */
 #define IOLN_DZ         010
 #define IOBA_RQB        (IOPAGEBASE + 000334 +  (020 * (DZ_MUXES / 2)))
@@ -198,8 +200,6 @@ typedef struct {
 #define IOLN_RQC        004
 #define IOBA_RQD        (IOPAGEBASE + IOBA_RQC + IOLN_RQC)
 #define IOLN_RQD        004
-#define IOBA_VH         (IOPAGEBASE + 000440)           /* DHQ11 */
-#define IOLN_VH         020
 #define IOBA_MEM        (IOPAGEBASE + 012100)           /* MSV11-P */
 #define IOLN_MEM        040
 #define IOBA_RQ         (IOPAGEBASE + 012150)           /* RQDX3 */
@@ -331,6 +331,8 @@ typedef struct {
 
 /* Device vectors */
 
+#define VEC_FLOAT       (0)                             /* Assigned by Auto Configure */
+
 #define VEC_QBUS        1                               /* Qbus system */
 #define VEC_Q           0x200                           /* Qbus vector offset */
 #define VEC_PTR         (VEC_Q + 0070)
diff --git a/VAX/vax630_defs.h b/VAX/vax630_defs.h
index 1c150f2b..9e91fa1a 100644
--- a/VAX/vax630_defs.h
+++ b/VAX/vax630_defs.h
@@ -235,6 +235,8 @@ typedef struct {
 
 /* I/O page layout - RQB,RQC,RQD float based on number of DZ's */
 
+#define IOBA_FLOAT      (0)                             /* Assigned by Auto Configure */
+
 #define IOBA_DZ         (IOPAGEBASE + 000100)           /* DZ11 */
 #define IOLN_DZ         010
 #define IOBA_RQB        (IOPAGEBASE + 000334 +  (020 * (DZ_MUXES / 2)))
@@ -243,8 +245,6 @@ typedef struct {
 #define IOLN_RQC        004
 #define IOBA_RQD        (IOPAGEBASE + IOBA_RQC + IOLN_RQC)
 #define IOLN_RQD        004
-#define IOBA_VH         (IOPAGEBASE + 000440)           /* DHQ11 */
-#define IOLN_VH         020
 #define IOBA_RQ         (IOPAGEBASE + 012150)           /* RQDX3 */
 #define IOLN_RQ         004
 #define IOBA_TS         (IOPAGEBASE + 012520)           /* TS11 */
@@ -318,6 +318,8 @@ typedef struct {
 #define INT_V_QDSS      19                              /* QDSS */
 #define INT_V_CR        20
 #define INT_V_QVSS      21                              /* QVSS */
+#define INT_V_DMCRX     22
+#define INT_V_DMCTX     23
 
 #define INT_CLK         (1u << INT_V_CLK)
 #define INT_RQ          (1u << INT_V_RQ)
@@ -342,6 +344,8 @@ typedef struct {
 #define INT_QDSS        (1u << INT_V_QDSS)
 #define INT_CR          (1u << INT_V_CR)
 #define INT_QVSS        (1u << INT_V_QVSS)
+#define INT_DMCRX       (1u << INT_V_DMCRX)
+#define INT_DMCTX       (1u << INT_V_DMCTX)
 
 #define IPL_CLK         (0x16 - IPL_HMIN)                       /* relative IPL */
 #define IPL_RQ          (0x14 - IPL_HMIN)
@@ -366,6 +370,8 @@ typedef struct {
 #define IPL_QDSS        (0x14 - IPL_HMIN)
 #define IPL_CR          (0x14 - IPL_HMIN)
 #define IPL_QVSS        (0x14 - IPL_HMIN)
+#define IPL_DMCRX       (0x15 - IPL_HMIN)
+#define IPL_DMCTX       (0x15 - IPL_HMIN)
 
 #define IPL_HMAX        0x17                            /* highest hwre level */
 #define IPL_HMIN        0x14                            /* lowest hwre level */
@@ -374,6 +380,8 @@ typedef struct {
 
 /* Device vectors */
 
+#define VEC_FLOAT       (0)                             /* Assigned by Auto Configure */
+
 #define VEC_QBUS        1                               /* Qbus system */
 #define VEC_Q           0x200                           /* Qbus vector offset */
 #define VEC_PTR         (VEC_Q + 0070)
diff --git a/VAX/vax730_defs.h b/VAX/vax730_defs.h
index cfcb327d..46905c0d 100644
--- a/VAX/vax730_defs.h
+++ b/VAX/vax730_defs.h
@@ -234,6 +234,8 @@ typedef struct {
 
 /* Unibus I/O page layout - XUB,RQB,RQC,RQD float based on number of DZ's */
 
+#define IOBA_FLOAT      (0)                             /* Assigned by Auto Configure */
+
 #define IOBA_DZ         (IOPAGEBASE + 000100)           /* DZ11 */
 #define IOLN_DZ         010
 #define IOBA_XUB        (IOPAGEBASE + 000330 + (020 * (DZ_MUXES / 2)))
@@ -289,11 +291,15 @@ typedef struct {
 #define INT_V_TS        7
 #define INT_V_RY        8
 #define INT_V_XU        9
+#define INT_V_DMCRX     10
+#define INT_V_DMCTX     11
 
 #define INT_V_LPT       0                               /* BR4 */
 #define INT_V_PTR       1
 #define INT_V_PTP       2
 #define INT_V_CR        3
+#define INT_V_VHRX      4
+#define INT_V_VHTX      5
 
 #define INT_DZRX        (1u << INT_V_DZRX)
 #define INT_DZTX        (1u << INT_V_DZTX)
@@ -306,9 +312,13 @@ typedef struct {
 #define INT_XU          (1u << INT_V_XU)
 #define INT_RB          (1u << INT_V_RB)
 #define INT_LPT         (1u << INT_V_LPT)
+#define INT_VHRX        (1u << INT_V_VHRX)
+#define INT_VHTX        (1u << INT_V_VHTX)
 #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)
@@ -324,9 +334,15 @@ typedef struct {
 #define IPL_PTR         (0x14 - IPL_HMIN)
 #define IPL_PTP         (0x14 - IPL_HMIN)
 #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 */
 
+#define VEC_FLOAT       (0)                             /* Assigned by Auto Configure */
+
 #define VEC_QBUS        0
 #define VEC_Q           0x200
 #define VEC_PTR         (VEC_Q + 0070)
diff --git a/VAX/vax730_syslist.c b/VAX/vax730_syslist.c
index f0ce5b84..e33ce16a 100644
--- a/VAX/vax730_syslist.c
+++ b/VAX/vax730_syslist.c
@@ -50,7 +50,9 @@ extern DEVICE ry_dev;
 extern DEVICE ts_dev;
 extern DEVICE tq_dev;
 extern DEVICE dz_dev;
+extern DEVICE vh_dev;
 extern DEVICE xu_dev, xub_dev;
+extern DEVICE dmc_dev[];
 
 extern int32 sim_switches;
 extern UNIT cpu_unit;
@@ -68,6 +70,7 @@ DEVICE *sim_devices[] = {
     &tto_dev,
     &td_dev,
     &dz_dev,
+    &vh_dev,
     &cr_dev,
     &lpt_dev,
     &rl_dev,
@@ -82,6 +85,10 @@ DEVICE *sim_devices[] = {
     &tq_dev,
     &xu_dev,
     &xub_dev,
+	&dmc_dev[0],
+	&dmc_dev[1],
+	&dmc_dev[2],
+	&dmc_dev[3],
     NULL
     };
 
diff --git a/VAX/vax750_defs.h b/VAX/vax750_defs.h
index 0ba24e7c..b186b78b 100644
--- a/VAX/vax750_defs.h
+++ b/VAX/vax750_defs.h
@@ -270,6 +270,8 @@ typedef struct {
 /* Unibus I/O page layout - XUB,RQB,RQC,RQD float based on number of DZ's
    Massbus devices (RP, TU) do not appear in the Unibus IO page */
 
+#define IOBA_FLOAT      (0)                             /* Assigned by Auto Configure */
+
 #define IOBA_DZ         (IOPAGEBASE + 000100)           /* DZ11 */
 #define IOLN_DZ         010
 #define IOBA_XUB        (IOPAGEBASE + 000330 + (020 * (DZ_MUXES / 2)))
@@ -322,11 +324,15 @@ 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
 #define INT_V_PTP       2
 #define INT_V_CR        3
+#define INT_V_VHRX      4
+#define INT_V_VHTX      5
 
 #define INT_DZRX        (1u << INT_V_DZRX)
 #define INT_DZTX        (1u << INT_V_DZTX)
@@ -338,9 +344,13 @@ typedef struct {
 #define INT_RY          (1u << INT_V_RY)
 #define INT_XU          (1u << INT_V_XU)
 #define INT_LPT         (1u << INT_V_LPT)
+#define INT_VHRX        (1u << INT_V_VHRX)
+#define INT_VHTX        (1u << INT_V_VHTX)
 #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)
@@ -355,9 +365,15 @@ typedef struct {
 #define IPL_PTR         (0x14 - IPL_HMIN)
 #define IPL_PTP         (0x14 - IPL_HMIN)
 #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 */
 
+#define VEC_FLOAT       (0)                             /* Assigned by Auto Configure */
+
 #define VEC_QBUS        0
 #define VEC_Q           0x200
 #define VEC_PTR         (VEC_Q + 0070)
diff --git a/VAX/vax750_syslist.c b/VAX/vax750_syslist.c
index b339104b..3d895757 100644
--- a/VAX/vax750_syslist.c
+++ b/VAX/vax750_syslist.c
@@ -52,7 +52,9 @@ extern DEVICE ts_dev;
 extern DEVICE tq_dev;
 extern DEVICE tu_dev;
 extern DEVICE dz_dev;
+extern DEVICE vh_dev;
 extern DEVICE xu_dev, xub_dev;
+extern DEVICE dmc_dev[];
 
 extern int32 sim_switches;
 extern UNIT cpu_unit;
@@ -72,6 +74,7 @@ DEVICE *sim_devices[] = {
     &tto_dev,
     &td_dev,
     &dz_dev,
+    &vh_dev,
     &cr_dev,
     &lpt_dev,
     &rp_dev,
@@ -87,6 +90,10 @@ DEVICE *sim_devices[] = {
     &tq_dev,
     &xu_dev,
     &xub_dev,
+	&dmc_dev[0],
+	&dmc_dev[1],
+	&dmc_dev[2],
+	&dmc_dev[3],
     NULL
     };
 
diff --git a/VAX/vax780_defs.h b/VAX/vax780_defs.h
index 48563b72..8305a58c 100644
--- a/VAX/vax780_defs.h
+++ b/VAX/vax780_defs.h
@@ -277,6 +277,8 @@ typedef struct {
 /* Unibus I/O page layout - XUB,RQB,RQC,RQD float based on number of DZ's
    Massbus devices (RP, TU) do not appear in the Unibus IO page */
 
+#define IOBA_FLOAT      (0)                             /* Assigned by Auto Configure */
+
 #define IOBA_DZ         (IOPAGEBASE + 000100)           /* DZ11 */
 #define IOLN_DZ         010
 #define IOBA_XUB        (IOPAGEBASE + 000330 + (020 * (DZ_MUXES / 2)))
@@ -287,8 +289,6 @@ typedef struct {
 #define IOLN_RQC        004
 #define IOBA_RQD        (IOPAGEBASE + IOBA_RQC + IOLN_RQC)
 #define IOLN_RQD        004
-#define IOBA_VH         (IOPAGEBASE + 000440)           /* DHU11 */
-#define IOLN_VH         020
 #define IOBA_RQ         (IOPAGEBASE + 012150)           /* UDA50 */
 #define IOLN_RQ         004
 #define IOBA_TS         (IOPAGEBASE + 012520)           /* TS11 */
@@ -319,8 +319,6 @@ typedef struct {
 #define IOLN_PTR        004
 #define IOBA_PTP        (IOPAGEBASE + 017554)           /* PC11 punch */
 #define IOLN_PTP        004
-#define IOBA_DMC        (IOPAGEBASE + 0760060)          /* DMC11 */
-#define IOLN_DMC        010
 
 /* Interrupt assignments; within each level, priority is right to left */
 
@@ -381,6 +379,8 @@ typedef struct {
 
 /* Device vectors */
 
+#define VEC_FLOAT       (0)                             /* Assigned by Auto Configure */
+
 #define VEC_QBUS        0
 #define VEC_Q           0000
 #define VEC_PTR         0070
@@ -398,10 +398,6 @@ typedef struct {
 #define VEC_RY          0264
 #define VEC_DZRX        0300
 #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/vaxmod_defs.h b/VAX/vaxmod_defs.h
index 8527f1b0..3e56d146 100644
--- a/VAX/vaxmod_defs.h
+++ b/VAX/vaxmod_defs.h
@@ -285,6 +285,8 @@ typedef struct {
 
 /* I/O page layout - RQB,RQC,RQD float based on number of DZ's */
 
+#define IOBA_FLOAT      (0)                             /* Assigned by Auto Configure */
+
 #define IOBA_DZ         (IOPAGEBASE + 000100)           /* DZ11 */
 #define IOLN_DZ         010
 #define IOBA_RQB        (IOPAGEBASE + 000334 +  (020 * (DZ_MUXES / 2)))
@@ -293,8 +295,6 @@ typedef struct {
 #define IOLN_RQC        004
 #define IOBA_RQD        (IOPAGEBASE + IOBA_RQC + IOLN_RQC)
 #define IOLN_RQD        004
-#define IOBA_VH         (IOPAGEBASE + 000440)           /* DHQ11 */
-#define IOLN_VH         020
 #define IOBA_RQ         (IOPAGEBASE + 012150)           /* RQDX3 */
 #define IOLN_RQ         004
 #define IOBA_TS         (IOPAGEBASE + 012520)           /* TS11 */
@@ -427,6 +427,8 @@ typedef struct {
 
 /* Device vectors */
 
+#define VEC_FLOAT       (0)                             /* Assigned by Auto Configure */
+
 #define VEC_QBUS        1                               /* Qbus system */
 #define VEC_Q           0x200                           /* Qbus vector offset */
 #define VEC_PTR         (VEC_Q + 0070)
diff --git a/Visual Studio Projects/PDP10.vcproj b/Visual Studio Projects/PDP10.vcproj
index 766ca9e9..0b0e6fdd 100644
--- a/Visual Studio Projects/PDP10.vcproj	
+++ b/Visual Studio Projects/PDP10.vcproj	
@@ -247,10 +247,6 @@
 				RelativePath="..\PDP11\pdp11_ry.c"
 				>
 			</File>
-			<File
-				RelativePath="..\PDP11\pdp11_xu.c"
-				>
-			</File>
 			<File
 				RelativePath="..\scp.c"
 				>
diff --git a/Visual Studio Projects/VAX620.vcproj b/Visual Studio Projects/VAX620.vcproj
index 9f690213..7e30e928 100644
--- a/Visual Studio Projects/VAX620.vcproj	
+++ b/Visual Studio Projects/VAX620.vcproj	
@@ -207,6 +207,10 @@
 				RelativePath="..\PDP11\pdp11_cr.c"
 				>
 			</File>
+			<File
+				RelativePath="..\PDP11\pdp11_dmc.c"
+				>
+			</File>
 			<File
 				RelativePath="..\PDP11\pdp11_dz.c"
 				>
@@ -369,6 +373,10 @@
 			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/Visual Studio Projects/VAX630.vcproj b/Visual Studio Projects/VAX630.vcproj
index 2eb6b7eb..259d5230 100644
--- a/Visual Studio Projects/VAX630.vcproj	
+++ b/Visual Studio Projects/VAX630.vcproj	
@@ -207,6 +207,10 @@
 				RelativePath="..\PDP11\pdp11_cr.c"
 				>
 			</File>
+			<File
+				RelativePath="..\PDP11\pdp11_dmc.c"
+				>
+			</File>
 			<File
 				RelativePath="..\PDP11\pdp11_dz.c"
 				>
@@ -369,6 +373,10 @@
 			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/Visual Studio Projects/VAX730.vcproj b/Visual Studio Projects/VAX730.vcproj
index 446cafcd..201977df 100644
--- a/Visual Studio Projects/VAX730.vcproj	
+++ b/Visual Studio Projects/VAX730.vcproj	
@@ -202,6 +202,10 @@
 				RelativePath="..\PDP11\pdp11_cr.c"
 				>
 			</File>
+			<File
+				RelativePath="..\PDP11\pdp11_dmc.c"
+				>
+			</File>
 			<File
 				RelativePath="..\PDP11\pdp11_dz.c"
 				>
@@ -238,6 +242,10 @@
 				RelativePath="..\PDP11\pdp11_ts.c"
 				>
 			</File>
+			<File
+				RelativePath="..\PDP11\pdp11_vh.c"
+				>
+			</File>
 			<File
 				RelativePath="..\PDP11\pdp11_xu.c"
 				>
@@ -371,6 +379,10 @@
 				RelativePath="..\dec_dz.h"
 				>
 			</File>
+			<File
+				RelativePath="..\PDP11\pdp11_dmc.h"
+				>
+			</File>
 			<File
 				RelativePath="..\PDP11\pdp11_io_lib.h"
 				>
diff --git a/Visual Studio Projects/VAX750.vcproj b/Visual Studio Projects/VAX750.vcproj
index f64d767e..982d4998 100644
--- a/Visual Studio Projects/VAX750.vcproj	
+++ b/Visual Studio Projects/VAX750.vcproj	
@@ -202,6 +202,10 @@
 				RelativePath="..\PDP11\pdp11_cr.c"
 				>
 			</File>
+			<File
+				RelativePath="..\PDP11\pdp11_dmc.c"
+				>
+			</File>
 			<File
 				RelativePath="..\PDP11\pdp11_dz.c"
 				>
@@ -246,6 +250,10 @@
 				RelativePath="..\PDP11\pdp11_tu.c"
 				>
 			</File>
+			<File
+				RelativePath="..\PDP11\pdp11_vh.c"
+				>
+			</File>
 			<File
 				RelativePath="..\PDP11\pdp11_xu.c"
 				>
@@ -379,6 +387,10 @@
 				RelativePath="..\dec_dz.h"
 				>
 			</File>
+			<File
+				RelativePath="..\PDP11\pdp11_dmc.h"
+				>
+			</File>
 			<File
 				RelativePath="..\PDP11\pdp11_io_lib.h"
 				>
diff --git a/descrip.mms b/descrip.mms
index 2ac2de0a..e86bcd7e 100644
--- a/descrip.mms
+++ b/descrip.mms
@@ -43,6 +43,8 @@
 #            SWTP6800MP-A2   Just Build The SWTP6800MP-A2.
 #            VAX             Just Build The DEC VAX.
 #            VAX610          Just Build The DEC VAX610 (MicroVAX I).
+#            VAX620          Just Build The DEC VAX610 (rtVAX 1000).
+#            VAX630          Just Build The DEC VAX610 (MicroVAX II).
 #            VAX730          Just Build The DEC VAX730.
 #            VAX750          Just Build The DEC VAX750.
 #            VAX780          Just Build The DEC VAX780.
@@ -661,6 +663,62 @@ VAX610_OPTIONS = /INCL=($(SIMH_DIR),$(VAX610_DIR),$(PDP11_DIR)$(PCAP_INC))\
 VAX610_SIMH_LIB = $(SIMH_LIB)
 .ENDIF
 
+# Digital Equipment VAX630 (MicroVAX II) Simulator Definitions.
+#
+VAX630_DIR = SYS$DISK:[.VAX]
+VAX630_LIB1 = $(LIB_DIR)VAX630L1-$(ARCH).OLB
+VAX630_SOURCE1 = $(VAX630_DIR)VAX_CPU.C,$(VAX630_DIR)VAX_CPU1.C,\
+                 $(VAX630_DIR)VAX_FPA.C,$(VAX630_DIR)VAX_CIS.C,\
+                 $(VAX630_DIR)VAX_OCTA.C,$(VAX630_DIR)VAX_CMODE.C,\
+                 $(VAX630_DIR)VAX_MMU.C,$(VAX630_DIR)VAX_SYS.C,\
+                 $(VAX630_DIR)VAX_SYSCM.C,$(VAX630_DIR)VAX630_STDDEV.C,\
+                 $(VAX630_DIR)VAX630_MEM.C,$(VAX630_DIR)VAX630_SYSDEV.C,\
+                 $(VAX630_DIR)VAX630_IO.C,$(VAX630_DIR)VAX630_SYSLIST.C
+VAX630_LIB2 = $(LIB_DIR)VAX630L2-$(ARCH).OLB
+VAX630_SOURCE2 = $(PDP11_DIR)PDP11_IO_LIB.C,\
+                 $(PDP11_DIR)PDP11_RL.C,$(PDP11_DIR)PDP11_RQ.C,\
+                 $(PDP11_DIR)PDP11_TS.C,$(PDP11_DIR)PDP11_DZ.C,\
+                 $(PDP11_DIR)PDP11_LP.C,$(PDP11_DIR)PDP11_TQ.C,\
+                 $(PDP11_DIR)PDP11_XQ.C,$(PDP11_DIR)PDP11_CR.C,\
+                 $(PDP11_DIR)PDP11_RY.C,$(PDP11_DIR)PDP11_VH.C
+.IFDEF ALPHA_OR_IA64
+VAX630_OPTIONS = /INCL=($(SIMH_DIR),$(VAX630_DIR),$(PDP11_DIR)$(PCAP_INC))\
+                 /DEF=($(CC_DEFS),"VM_VAX=1","USE_ADDR64=1","USE_INT64=1"$(PCAP_DEFS),"VAX_630=1")
+VAX630_SIMH_LIB = $(SIMH_LIB64)
+.ELSE
+VAX630_OPTIONS = /INCL=($(SIMH_DIR),$(VAX630_DIR),$(PDP11_DIR)$(PCAP_INC))\
+                 /DEF=($(CC_DEFS),"VM_VAX=1"$(PCAP_DEFS),"VAX_630=1")
+VAX630_SIMH_LIB = $(SIMH_LIB)
+.ENDIF
+
+# Digital Equipment VAX620 (rtVAX 1000) Simulator Definitions.
+#
+VAX620_DIR = SYS$DISK:[.VAX]
+VAX620_LIB1 = $(LIB_DIR)VAX620L1-$(ARCH).OLB
+VAX620_SOURCE1 = $(VAX620_DIR)VAX_CPU.C,$(VAX620_DIR)VAX_CPU1.C,\
+                 $(VAX620_DIR)VAX_FPA.C,$(VAX620_DIR)VAX_CIS.C,\
+                 $(VAX620_DIR)VAX_OCTA.C,$(VAX620_DIR)VAX_CMODE.C,\
+                 $(VAX620_DIR)VAX_MMU.C,$(VAX620_DIR)VAX_SYS.C,\
+                 $(VAX620_DIR)VAX_SYSCM.C,$(VAX620_DIR)VAX620_STDDEV.C,\
+                 $(VAX620_DIR)VAX620_MEM.C,$(VAX620_DIR)VAX620_SYSDEV.C,\
+                 $(VAX620_DIR)VAX620_IO.C,$(VAX620_DIR)VAX620_SYSLIST.C
+VAX620_LIB2 = $(LIB_DIR)VAX620L2-$(ARCH).OLB
+VAX620_SOURCE2 = $(PDP11_DIR)PDP11_IO_LIB.C,\
+                 $(PDP11_DIR)PDP11_RL.C,$(PDP11_DIR)PDP11_RQ.C,\
+                 $(PDP11_DIR)PDP11_TS.C,$(PDP11_DIR)PDP11_DZ.C,\
+                 $(PDP11_DIR)PDP11_LP.C,$(PDP11_DIR)PDP11_TQ.C,\
+                 $(PDP11_DIR)PDP11_XQ.C,$(PDP11_DIR)PDP11_CR.C,\
+                 $(PDP11_DIR)PDP11_RY.C,$(PDP11_DIR)PDP11_VH.C
+.IFDEF ALPHA_OR_IA64
+VAX620_OPTIONS = /INCL=($(SIMH_DIR),$(VAX620_DIR),$(PDP11_DIR)$(PCAP_INC))\
+                 /DEF=($(CC_DEFS),"VM_VAX=1","USE_ADDR64=1","USE_INT64=1"$(PCAP_DEFS),"VAX_620=1")
+VAX620_SIMH_LIB = $(SIMH_LIB64)
+.ELSE
+VAX620_OPTIONS = /INCL=($(SIMH_DIR),$(VAX620_DIR),$(PDP11_DIR)$(PCAP_INC))\
+                 /DEF=($(CC_DEFS),"VM_VAX=1"$(PCAP_DEFS),"VAX_620=1")
+VAX620_SIMH_LIB = $(SIMH_LIB)
+.ENDIF
+
 # Digital Equipment VAX730 Simulator Definitions.
 #
 VAX730_DIR = SYS$DISK:[.VAX]
@@ -679,6 +737,7 @@ VAX730_SOURCE2 = $(PDP11_DIR)PDP11_RL.C,$(PDP11_DIR)PDP11_RQ.C,\
                  $(PDP11_DIR)PDP11_LP.C,$(PDP11_DIR)PDP11_TQ.C,\
                  $(PDP11_DIR)PDP11_XU.C,$(PDP11_DIR)PDP11_RY.C,\
                  $(PDP11_DIR)PDP11_CR.C,$(PDP11_DIR)PDP11_HK.C,\
+                 $(PDP11_DIR)PDP11_VH.C,$(PDP11_DIR)PDP11_DMC.C,\
                  $(PDP11_DIR)PDP11_IO_LIB.C
 .IFDEF ALPHA_OR_IA64
 VAX730_OPTIONS = /INCL=($(SIMH_DIR),$(VAX730_DIR),$(PDP11_DIR)$(PCAP_INC))\
@@ -709,6 +768,7 @@ VAX750_SOURCE2 = $(PDP11_DIR)PDP11_RL.C,$(PDP11_DIR)PDP11_RQ.C,\
                  $(PDP11_DIR)PDP11_XU.C,$(PDP11_DIR)PDP11_RY.C,\
                  $(PDP11_DIR)PDP11_CR.C,$(PDP11_DIR)PDP11_HK.C,\
                  $(PDP11_DIR)PDP11_RP.C,$(PDP11_DIR)PDP11_TU.C,\
+                 $(PDP11_DIR)PDP11_VH.C,$(PDP11_DIR)PDP11_DMC.C,\
                  $(PDP11_DIR)PDP11_IO_LIB.C
 .IFDEF ALPHA_OR_IA64
 VAX750_OPTIONS = /INCL=($(SIMH_DIR),$(VAX750_DIR),$(PDP11_DIR)$(PCAP_INC))\
@@ -768,7 +828,7 @@ I7094_OPTIONS = /INCL=($(SIMH_DIR),$(I7094_DIR))/DEF=($(CC_DEFS))
 .IFDEF ALPHA_OR_IA64
 ALL : ALTAIR ALTAIRZ80 ECLIPSE GRI LGP H316 HP2100 I1401 I1620 IBM1130 ID16 \
       ID32 NOVA PDP1 PDP4 PDP7 PDP8 PDP9 PDP10 PDP11 PDP15 S3 \
-      VAX VAX610 VAX730 VAX750 VAX780 \
+      VAX VAX610 VAX620 VAX630 VAX730 VAX750 VAX780 \
       SDS I7094 SWTP6800MP-A SWTP6800MP-A2
         $! No further actions necessary
 .ELSE
@@ -777,7 +837,8 @@ ALL : ALTAIR ALTAIRZ80 ECLIPSE GRI LGP H316 HP2100 I1401 I1620 IBM1130 ID16 \
 #
 ALL : ALTAIR ALTAIRZ80 GRI H316 HP2100 I1401 I1620 IBM1130 ID16 ID32 \
       NOVA PDP1 PDP4 PDP7 PDP8 PDP9 PDP11 PDP15 S3 \
-      VAX VAX510 VAX730 VAX750 VAX780 SDS SWTP6800MP-A SWTP6800MP-A2
+      VAX VAX510 VAX620 VAX630 VAX730 VAX750 VAX780 SDS \
+      SWTP6800MP-A SWTP6800MP-A2
         $! No further actions necessary
 .ENDIF
 
@@ -1217,6 +1278,52 @@ $(VAX610_LIB2) : $(VAX610_SOURCE2)
         $ LIBRARY/REPLACE $(MMS$TARGET) $(BLD_DIR)*.OBJ
         $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
 
+$(VAX630_LIB1) : $(VAX630_SOURCE1)
+        $!
+        $! Building The $(VAX630_LIB1) Library.
+        $!
+        $ RUN/NODEBUG $(BIN_DIR)BuildROMs-$(ARCH).EXE
+        $ $(CC)$(VAX630_OPTIONS)/OBJ=$(VAX630_DIR) -
+               /OBJ=$(BLD_DIR) $(MMS$CHANGED_LIST)
+        $ IF (F$SEARCH("$(MMS$TARGET)").EQS."") THEN -
+             LIBRARY/CREATE $(MMS$TARGET)
+        $ LIBRARY/REPLACE $(MMS$TARGET) $(BLD_DIR)*.OBJ
+        $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
+
+$(VAX620_LIB2) : $(VAX620_SOURCE2)
+        $!
+        $! Building The $(VAX620_LIB2) Library.
+        $!
+        $ $(CC)$(VAX620_OPTIONS)/OBJ=$(VAX620_DIR) -
+               /OBJ=$(BLD_DIR) $(MMS$CHANGED_LIST)
+        $ IF (F$SEARCH("$(MMS$TARGET)").EQS."") THEN -
+             LIBRARY/CREATE $(MMS$TARGET)
+        $ LIBRARY/REPLACE $(MMS$TARGET) $(BLD_DIR)*.OBJ
+        $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
+
+$(VAX620_LIB1) : $(VAX620_SOURCE1)
+        $!
+        $! Building The $(VAX620_LIB1) Library.
+        $!
+        $ RUN/NODEBUG $(BIN_DIR)BuildROMs-$(ARCH).EXE
+        $ $(CC)$(VAX620_OPTIONS)/OBJ=$(VAX620_DIR) -
+               /OBJ=$(BLD_DIR) $(MMS$CHANGED_LIST)
+        $ IF (F$SEARCH("$(MMS$TARGET)").EQS."") THEN -
+             LIBRARY/CREATE $(MMS$TARGET)
+        $ LIBRARY/REPLACE $(MMS$TARGET) $(BLD_DIR)*.OBJ
+        $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
+
+$(VAX620_LIB2) : $(VAX620_SOURCE2)
+        $!
+        $! Building The $(VAX620_LIB2) Library.
+        $!
+        $ $(CC)$(VAX620_OPTIONS)/OBJ=$(VAX620_DIR) -
+               /OBJ=$(BLD_DIR) $(MMS$CHANGED_LIST)
+        $ IF (F$SEARCH("$(MMS$TARGET)").EQS."") THEN -
+             LIBRARY/CREATE $(MMS$TARGET)
+        $ LIBRARY/REPLACE $(MMS$TARGET) $(BLD_DIR)*.OBJ
+        $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
+
 $(VAX730_LIB1) : $(VAX730_SOURCE1)
         $!
         $! Building The $(VAX730_LIB1) Library.
@@ -1681,6 +1788,36 @@ $(BIN_DIR)VAX610-$(ARCH).EXE : $(SIMH_MAIN) $(VAX610_SIMH_LIB) $(PCAP_LIBD) $(VA
                $(VAX610_SIMH_LIB)/LIBRARY$(PCAP_LIBR)
         $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
 
+VAX630 : $(BIN_DIR)VAX630-$(ARCH).EXE
+        $! VAX630 done
+
+$(BIN_DIR)VAX630-$(ARCH).EXE : $(SIMH_MAIN) $(VAX630_SIMH_LIB) $(PCAP_LIBD) $(VAX630_LIB1) $(VAX630_LIB2) $(PCAP_EXECLET)
+        $!
+        $! Building The $(BIN_DIR)VAX630-$(ARCH).EXE Simulator.
+        $!
+        $ $(CC)$(VAX630_OPTIONS)/OBJ=$(BLD_DIR) SCP.C
+        $ LINK $(LINK_DEBUG)$(LINK_SECTION_BINDING)-
+               /EXE=$(BIN_DIR)VAX630-$(ARCH).EXE -
+               $(BLD_DIR)SCP.OBJ,-
+               $(VAX630_LIB1)/LIBRARY,$(VAX630_LIB2)/LIBRARY,-
+               $(VAX630_SIMH_LIB)/LIBRARY$(PCAP_LIBR)
+        $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
+
+VAX620 : $(BIN_DIR)VAX620-$(ARCH).EXE
+        $! VAX620 done
+
+$(BIN_DIR)VAX620-$(ARCH).EXE : $(SIMH_MAIN) $(VAX620_SIMH_LIB) $(PCAP_LIBD) $(VAX620_LIB1) $(VAX620_LIB2) $(PCAP_EXECLET)
+        $!
+        $! Building The $(BIN_DIR)VAX620-$(ARCH).EXE Simulator.
+        $!
+        $ $(CC)$(VAX620_OPTIONS)/OBJ=$(BLD_DIR) SCP.C
+        $ LINK $(LINK_DEBUG)$(LINK_SECTION_BINDING)-
+               /EXE=$(BIN_DIR)VAX620-$(ARCH).EXE -
+               $(BLD_DIR)SCP.OBJ,-
+               $(VAX620_LIB1)/LIBRARY,$(VAX620_LIB2)/LIBRARY,-
+               $(VAX620_SIMH_LIB)/LIBRARY$(PCAP_LIBR)
+        $ DELETE/NOLOG/NOCONFIRM $(BLD_DIR)*.OBJ;*
+
 VAX730 : $(BIN_DIR)VAX730-$(ARCH).EXE
         $! VAX730 done
 
diff --git a/makefile b/makefile
index 5bd7a2e9..3bfcf389 100644
--- a/makefile
+++ b/makefile
@@ -514,7 +514,7 @@ VAX630 = ${VAXD}/vax_cpu.c ${VAXD}/vax_cpu1.c ${VAXD}/vax_fpa.c \
 	${PDP11D}/pdp11_rl.c ${PDP11D}/pdp11_rq.c ${PDP11D}/pdp11_ts.c \
 	${PDP11D}/pdp11_dz.c ${PDP11D}/pdp11_lp.c ${PDP11D}/pdp11_tq.c \
 	${PDP11D}/pdp11_xq.c ${PDP11D}/pdp11_ry.c ${PDP11D}/pdp11_vh.c \
-	${PDP11D}/pdp11_cr.c ${PDP11D}/pdp11_io_lib.c
+	${PDP11D}/pdp11_cr.c ${PDP11D}/pdp11_dmc.c ${PDP11D}/pdp11_io_lib.c
 VAX620_OPT = -DVM_VAX -DVAX_620 -DUSE_INT64 -DUSE_ADDR64 -I ${VAXD} -I ${PDP11D} ${NETWORK_OPT}
 VAX630_OPT = -DVM_VAX -DVAX_630 -DUSE_INT64 -DUSE_ADDR64 -I ${VAXD} -I ${PDP11D} ${NETWORK_OPT}
 
@@ -527,7 +527,8 @@ VAX730 = ${VAXD}/vax_cpu.c ${VAXD}/vax_cpu1.c ${VAXD}/vax_fpa.c \
 	${PDP11D}/pdp11_rl.c ${PDP11D}/pdp11_rq.c ${PDP11D}/pdp11_ts.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_hk.c ${PDP11D}/pdp11_io_lib.c
+	${PDP11D}/pdp11_hk.c ${PDP11D}/pdp11_vh.c ${PDP11D}/pdp11_dmc.c \
+	${PDP11D}/pdp11_io_lib.c
 VAX730_OPT = -DVM_VAX -DVAX_730 -DUSE_INT64 -DUSE_ADDR64 -I VAX -I ${PDP11D} ${NETWORK_OPT}
 
 
@@ -541,7 +542,7 @@ VAX750 = ${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_hk.c ${PDP11D}/pdp11_rp.c ${PDP11D}/pdp11_tu.c \
-	${PDP11D}/pdp11_io_lib.c
+	${PDP11D}/pdp11_vh.c ${PDP11D}/pdp11_dmc.c ${PDP11D}/pdp11_io_lib.c
 VAX750_OPT = -DVM_VAX -DVAX_750 -DUSE_INT64 -DUSE_ADDR64 -I VAX -I ${PDP11D} ${NETWORK_OPT}
 
 
@@ -555,7 +556,7 @@ 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_dmc.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}