diff --git a/IBM360/ibm360_cdp.c b/IBM360/ibm360_cdp.c
index 7d1cec3..bbb7b99 100644
--- a/IBM360/ibm360_cdp.c
+++ b/IBM360/ibm360_cdp.c
@@ -80,7 +80,13 @@ t_stat              cdp_detach(UNIT *);
 UNIT                cdp_unit[] = {
     {UDATA(cdp_srv, UNIT_CDP, 0), 600, UNIT_ADDR(0x00D) },       /* A */
 #if NUM_DEVS_CDP > 1
-    {UDATA(cdp_srv, UNIT_CDP, 0), 600, UNIT_ADDR(0x01D)},       /* A */
+    {UDATA(cdp_srv, UNIT_CDP | UNIT_DIS, 0), 600, UNIT_ADDR(0x01D)},       /* A */
+#if NUM_DEVS_CDP > 2
+    {UDATA(cdp_srv, UNIT_CDP | UNIT_DIS, 0), 600, UNIT_ADDR(0x40D)},       /* A */
+#if NUM_DEVS_CDP > 3
+    {UDATA(cdp_srv, UNIT_CDP | UNIT_DIS, 0), 600, UNIT_ADDR(0x41D)},       /* A */
+#endif
+#endif
 #endif
 };
 
diff --git a/IBM360/ibm360_cdr.c b/IBM360/ibm360_cdr.c
index 15833cc..071be67 100644
--- a/IBM360/ibm360_cdr.c
+++ b/IBM360/ibm360_cdr.c
@@ -85,7 +85,13 @@ t_stat              cdr_detach(UNIT *);
 UNIT                cdr_unit[] = {
    {UDATA(cdr_srv, UNIT_CDR, 0), 300, UNIT_ADDR(0x0C)},       /* A */
 #if NUM_DEVS_CDR > 1
-   {UDATA(cdr_srv, UNIT_CDR, 0), 300, UNIT_ADDR(0x1C)},       /* B */
+   {UDATA(cdr_srv, UNIT_CDR | UNIT_DIS, 0), 300, UNIT_ADDR(0x1C)},       /* B */
+#if NUM_DEVS_CDR > 2
+   {UDATA(cdr_srv, UNIT_CDR | UNIT_DIS, 0), 300, UNIT_ADDR(0x40C)},       /* B */
+#if NUM_DEVS_CDR > 3
+   {UDATA(cdr_srv, UNIT_CDR | UNIT_DIS, 0), 300, UNIT_ADDR(0x41C)},       /* B */
+#endif
+#endif
 #endif
 };
 
diff --git a/IBM360/ibm360_defs.h b/IBM360/ibm360_defs.h
index 8c61cb7..eea80e8 100644
--- a/IBM360/ibm360_defs.h
+++ b/IBM360/ibm360_defs.h
@@ -60,11 +60,11 @@
 #define     MAX_MUX         2
 
 /* Define number of supported units for each device type */
-#define NUM_DEVS_CDP        1
-#define NUM_DEVS_CDR        1
+#define NUM_DEVS_CDP        4
+#define NUM_DEVS_CDR        4
 #define NUM_DEVS_CON        1
-#define NUM_DEVS_LPR        1
-#define NUM_DEVS_MT         1
+#define NUM_DEVS_LPR        4
+#define NUM_DEVS_MT         2
 #define NUM_UNITS_MT        8
 #define NUM_DEVS_DASD       4
 #define NUM_UNITS_DASD      8
diff --git a/IBM360/ibm360_lpr.c b/IBM360/ibm360_lpr.c
index d19885b..6d1e45c 100644
--- a/IBM360/ibm360_lpr.c
+++ b/IBM360/ibm360_lpr.c
@@ -90,7 +90,13 @@ t_stat              lpr_getlpp(FILE *, UNIT *, int32, CONST void *);
 UNIT                lpr_unit[] = {
     {UDATA(lpr_srv, UNIT_LPR, 55), 300, UNIT_ADDR(0x0E)},       /* A */
 #if NUM_DEVS_LPR > 1
-    {UDATA(lpr_srv, UNIT_LPR, 55), 300, UNIT_ADDR(0x1E)},       /* B */
+    {UDATA(lpr_srv, UNIT_LPR | UNIT_DIS, 55), 300, UNIT_ADDR(0x1E)},       /* B */
+#if NUM_DEVS_LPR > 2
+    {UDATA(lpr_srv, UNIT_LPR | UNIT_DIS, 55), 300, UNIT_ADDR(0x40E)},       /* B */
+#if NUM_DEVS_LPR > 3
+    {UDATA(lpr_srv, UNIT_LPR | UNIT_DIS, 55), 300, UNIT_ADDR(0x41E)},       /* B */
+#endif
+#endif
 #endif
 };
 
diff --git a/IBM360/ibm360_mt.c b/IBM360/ibm360_mt.c
index 4e9d157..a065d4d 100644
--- a/IBM360/ibm360_mt.c
+++ b/IBM360/ibm360_mt.c
@@ -197,7 +197,7 @@ DEVICE              mtb_dev = {
     "MTB", mtb_unit, NULL, mt_mod,
     NUM_UNITS_MT, 8, 15, 1, 8, 8,
     NULL, NULL, &mt_reset, &mt_boot, &mt_attach, &mt_detach,
-    &mtb_dib, DEV_BUF_NUM(1) | DEV_DISABLE | DEV_DEBUG | DEV_TAPE, 0, dev_debug
+    &mtb_dib, DEV_BUF_NUM(1) | DEV_DISABLE | DEV_DIS | DEV_DEBUG | DEV_TAPE, 0, dev_debug
 };
 #endif
 
diff --git a/doc/ibm360.doc b/doc/ibm360.doc
index 2abf580..e4d48c4 100644
Binary files a/doc/ibm360.doc and b/doc/ibm360.doc differ