diff --git a/PDP10/ka10_dpk.c b/PDP10/ka10_dpk.c
index 4f6b920..d83994d 100644
--- a/PDP10/ka10_dpk.c
+++ b/PDP10/ka10_dpk.c
@@ -112,7 +112,7 @@ DEVICE dpk_dev = {
     DPK_NAME, dpk_unit, NULL, dpk_mod,
     2, 8, 0, 1, 8, 36,
     NULL, NULL, dpk_reset, NULL, dpk_attach, dpk_detach,
-    &dpk_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG, 0, dev_debug,
+    &dpk_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG | DEV_MUX, 0, dev_debug,
     NULL, NULL, dpk_help, NULL, NULL, dpk_description
 };
 
diff --git a/PDP10/ka10_iii.c b/PDP10/ka10_iii.c
index 0c9cc1b..5577684 100644
--- a/PDP10/ka10_iii.c
+++ b/PDP10/ka10_iii.c
@@ -320,7 +320,7 @@ DEVICE iii_dev = {
     "III", iii_unit, NULL, iii_mod,
     2, 10, 31, 1, 8, 8,
     NULL, NULL, iii_reset,
-    NULL, NULL, NULL, &iii_dib, DEV_DEBUG | DEV_DISABLE | DEV_DIS, 0, dev_debug,
+    NULL, NULL, NULL, &iii_dib, DEV_DEBUG | DEV_DISABLE | DEV_DIS | DEV_DISPLAY, 0, dev_debug,
     NULL, NULL, &iii_help, NULL, NULL, &iii_description
     };
 
diff --git a/PDP10/ka10_mty.c b/PDP10/ka10_mty.c
index f47e4a9..dce7331 100644
--- a/PDP10/ka10_mty.c
+++ b/PDP10/ka10_mty.c
@@ -94,7 +94,7 @@ DEVICE mty_dev = {
     MTY_NAME, mty_unit, NULL, mty_mod,
     2, 8, 0, 1, 8, 36,
     NULL, NULL, mty_reset, NULL, mty_attach, mty_detach,
-    &mty_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG, 0, dev_debug,
+    &mty_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG | DEV_MUX, 0, dev_debug,
     NULL, NULL, mty_help, NULL, NULL, mty_description
 };
 
diff --git a/PDP10/ka10_tk10.c b/PDP10/ka10_tk10.c
index 1ddfcd7..9815c29 100644
--- a/PDP10/ka10_tk10.c
+++ b/PDP10/ka10_tk10.c
@@ -92,7 +92,7 @@ DEVICE tk10_dev = {
     TK10_NAME, tk10_unit, NULL, tk10_mod,
     1, 8, 0, 1, 8, 36,
     NULL, NULL, tk10_reset, NULL, tk10_attach, tk10_detach,
-    &tk10_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG, 0, dev_debug,
+    &tk10_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG | DEV_MUX, 0, dev_debug,
     NULL, NULL, tk10_help, NULL, NULL, tk10_description
 };
 
diff --git a/PDP10/kl10_fe.c b/PDP10/kl10_fe.c
index b259396..39e0eba 100644
--- a/PDP10/kl10_fe.c
+++ b/PDP10/kl10_fe.c
@@ -554,7 +554,7 @@ DEVICE tty_dev = {
     2, 10, 31, 1, 8, 8,
     &tmxr_ex, &tmxr_dep, &tty_reset,
     NULL, &tty_attach, &tty_detach,
-    NULL, DEV_NET | DEV_DISABLE | DEV_DEBUG, 0, dev_debug,
+    NULL, DEV_MUX | DEV_DISABLE | DEV_DEBUG, 0, dev_debug,
     NULL, NULL, &tty_help, NULL, NULL, &tty_description
     };
 #endif
diff --git a/PDP10/kl10_nia.c b/PDP10/kl10_nia.c
index a755703..734649a 100644
--- a/PDP10/kl10_nia.c
+++ b/PDP10/kl10_nia.c
@@ -419,7 +419,7 @@ DEVICE nia_dev = {
     "NI", nia_unit, nia_reg, nia_mod,
     3, 8, 0, 1, 8, 36,
     NULL, NULL, &nia_reset, NULL, &nia_attach, &nia_detach,
-    &nia_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG, 0, nia_debug,
+    &nia_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG | DEV_ETHER, 0, nia_debug,
     NULL, NULL, &nia_help, NULL, NULL, &nia_description
 };
 
diff --git a/PDP10/kx10_dc.c b/PDP10/kx10_dc.c
index e2d7bf1..8e65245 100644
--- a/PDP10/kx10_dc.c
+++ b/PDP10/kx10_dc.c
@@ -147,7 +147,7 @@ DEVICE dc_dev = {
     1, 10, 31, 1, 8, 8,
     &tmxr_ex, &tmxr_dep, &dc_reset,
     NULL, &dc_attach, &dc_detach,
-    &dc_dib, DEV_NET | DEV_DISABLE | DEV_DEBUG, 0, dev_debug,
+    &dc_dib, DEV_MUX | DEV_DISABLE | DEV_DEBUG, 0, dev_debug,
     NULL, NULL, &dc_help, NULL, NULL, &dc_description
     };
 
@@ -436,15 +436,15 @@ t_stat dc_setnl (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
     if ((newln == 0) || (newln > DC10_MLINES) || (newln % 8) != 0)
         return SCPE_ARG;
     if (newln < dc_desc.lines) {
-        for (i = newln, t = 0; i < dc_desc.lines; i++)
+        for (i = newln - 1, t = 0; i < dc_desc.lines; i++)
             t = t | dc_ldsc[i].conn;
         if (t && !get_yn ("This will disconnect users; proceed [N]?", FALSE))
             return SCPE_OK;
-        for (i = newln; i < dc_desc.lines; i++) {
+        for (i = newln - 1; i < dc_desc.lines; i++) {
             if (dc_ldsc[i].conn) {
                 tmxr_linemsg (&dc_ldsc[i], "\r\nOperator disconnected line\r\n");
                 tmxr_send_buffered_data (&dc_ldsc[i]);
-                }
+            }
             tmxr_detach_ln (&dc_ldsc[i]);               /* completely reset line */
         }
     }
@@ -468,7 +468,7 @@ t_stat dc_set_log (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
     if ((cptr == NULL) || (*cptr == 0) || (gbuf[0] == 0))
         return SCPE_ARG;
     ln = (int32) get_uint (gbuf, 10, dc_desc.lines, &r);
-    if ((r != SCPE_OK) || (ln >= dc_desc.lines))
+    if ((r != SCPE_OK) || (ln > dc_desc.lines))
         return SCPE_ARG;
     return tmxr_set_log (NULL, ln, cptr, desc);
 }
@@ -483,7 +483,7 @@ t_stat dc_set_nolog (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
     if (cptr == NULL)
         return SCPE_ARG;
     ln = (int32) get_uint (cptr, 10, dc_desc.lines, &r);
-    if ((r != SCPE_OK) || (ln >= dc_desc.lines))
+    if ((r != SCPE_OK) || (ln > dc_desc.lines))
         return SCPE_ARG;
     return tmxr_set_nolog (NULL, ln, NULL, desc);
 }
diff --git a/PDP10/kx10_dpy.c b/PDP10/kx10_dpy.c
index 2f7039f..668cda4 100644
--- a/PDP10/kx10_dpy.c
+++ b/PDP10/kx10_dpy.c
@@ -44,7 +44,7 @@
  *    ;340 CONO BITS ARE:
  *            ;2.3            CLEAR NO INK MODE
  *            ;2.2            SET NO INK MODE (IN NO INK MODE, NO INTENSIFICATION CAN \
- *     OCCUR) 
+ *     OCCUR)
  *            ;2.1            CLEAR HALF WORD MODE
  *            ;1.9            SET HALF WORD MODE
  *            ;1.8            RESUME DISPLAY (TO CONTINUE AFTER A SPECIAL INTERUPT)
@@ -78,7 +78,7 @@
  *           7 PI channel?
  *   DISCON = CHAN + 140 (continue?)
  * *NO* DATAO or BLKO to device 130!
- *    
+ *
  * It appears that the reloc/protect mechanism is on I/O device 134.
  * (referred to by number, not symbol!)
  * DATAO sets reloc/protect, start addr
@@ -193,7 +193,7 @@ DEVICE dpy_dev = {
     NUM_DEVS_DPY, 0, 0, 0, 0, 0,
     NULL, NULL, dpy_reset,
     NULL, NULL, NULL,
-    &dpy_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG, 0, NULL,      
+    &dpy_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG | DEV_DISPLAY, 0, NULL,
     NULL, NULL, NULL, NULL, NULL, &dpy_description
     };
 
@@ -297,7 +297,7 @@ t_stat dpy_devio(uint32 dev, uint64 *data) {
         /* if fed using BLKO from interrupt vector, PC will be wrong! */
         sim_debug(DEBUG_DATAIO, &dpy_dev, "DPY %03o DATO %012llo PC=%06o\n",
                   dev, *data, PC);
-        
+
         inst = (uint32)LRZ(*data);
         if (dpy_update_status(uptr, ty340_instruction(inst), 0)) {
             /* still running */
diff --git a/PDP10/kx10_imp.c b/PDP10/kx10_imp.c
index 53323ed..4ebd6c1 100644
--- a/PDP10/kx10_imp.c
+++ b/PDP10/kx10_imp.c
@@ -563,7 +563,7 @@ DEVICE imp_dev = {
     "IMP", imp_unit, imp_reg, imp_mod,
     3, 8, 0, 1, 8, 36,
     NULL, NULL, &imp_reset, NULL, &imp_attach, &imp_detach,
-    &imp_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG, 0, imp_debug,
+    &imp_dib, DEV_DISABLE | DEV_DIS | DEV_DEBUG | DEV_ETHER, 0, imp_debug,
     NULL, NULL, &imp_help, NULL, NULL, &imp_description
 };
 #define IMP_OCHN     0000007