diff --git a/Makefile b/Makefile
index 35be68fd..1caebd03 100644
--- a/Makefile
+++ b/Makefile
@@ -65,7 +65,7 @@ TV11=tools/tv11/tv11
 PDP6=tools/pdp6/emu/pdp6
 
 H3TEXT=$(shell cd build; ls h3text.*)
-DDT=$(shell cd src; ls sysen1/ddt.* syseng/lsrtns.* syseng/msgs.* syseng/datime.*)
+DDT=$(shell cd src; ls sysen1/ddt.* syseng/lsrtns.* syseng/msgs.* syseng/datime.* syseng/ntsddt.*)
 SALV=$(shell cd src; ls kshack/nsalv.* syseng/format.* syseng/rfn.*)
 KSFEDR=$(shell cd src; ls kshack/ksfedr.*)
 DUMP=$(shell cd src; ls syseng/dump.* sysnet/netwrk.*)
diff --git a/build/ka10/include.tcl b/build/ka10/include.tcl
index 09a93780..ba73084d 100644
--- a/build/ka10/include.tcl
+++ b/build/ka10/include.tcl
@@ -56,6 +56,10 @@ proc make_ntsddt {} {
     respond "dsksw=" "0\r"
     respond "1PRSW=" "1\r"
     expect ":KILL"
+
+    # Old NTS DDT with 340 support.
+    respond "*" ":midas dsk0:.;@ ntsddt_syseng; ntsddt\r"
+    expect ":KILL"
 }
 
 proc make_salv {} {
diff --git a/build/kl10/include.tcl b/build/kl10/include.tcl
new file mode 100644
index 00000000..eaebbe4e
--- /dev/null
+++ b/build/kl10/include.tcl
@@ -0,0 +1,9 @@
+make_ntsddt {} {
+    # KL10 NTSDDT.
+    respond "*" ":midas dsk0:.;@ ntsddt_system;ddt\r"
+    respond "cpusw=" "2\r"
+    respond "ndsk=" "1\r"
+    respond "dsksw=" "3\r"
+    respond "1PRSW=" "1\r"
+    expect ":KILL"
+}
diff --git a/build/misc.tcl b/build/misc.tcl
index 76afd245..14eccf14 100644
--- a/build/misc.tcl
+++ b/build/misc.tcl
@@ -49,10 +49,6 @@ expect ":KILL"
 respond "*" ":midas;324 dsk0:.;@ sysgen_syseng; system gen\r"
 expect ":KILL"
 
-# Old NTS DDT with 340 support.
-respond "*" ":midas;324 dsk0:.;@ ntsddt_syseng; ntsddt\r"
-expect ":KILL"
-
 respond "*" ":midas sys3;ts syslod_sysen1;syslod\r"
 expect ":KILL"
 
@@ -1610,14 +1606,6 @@ expect ":KILL"
 respond "*" ":palx kldcp; kldcp\r"
 expect ":KILL"
 
-# KL10 NTSDDT.
-respond "*" ":midas dsk0:.;@ ntsddt_system;ddt\r"
-respond "cpusw=" "2\r"
-respond "ndsk=" "1\r"
-respond "dsksw=" "3\r"
-respond "1PRSW=" "1\r"
-expect ":KILL"
-
 # IOELEV, PDP-11 doing I/O for the PDP-10 host.
 # First, the "AI" IOELEV, also known as CHAOS-11.
 # STUFF prefers to have it in the "." directory.