diff --git a/Makefile b/Makefile
index 8cdcdad1..4be9c23c 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,16 @@ GIT ?= git
 CAT ?= cat
 WGET ?= wget
 TAR ?= tar
+
+ifeq ($(EMULATOR),pdp10-ka)
+MCHN ?= KA
+else
+ifeq ($(EMULATOR),pdp10-kl)
+MCHN ?= KL
+else
 MCHN ?= DB
+endif
+endif
 
 IMAGES=http://hactrn.org/images/
 
@@ -224,11 +233,11 @@ out/klh10/stamp/pdp10:: $(KLH10) start out/klh10/dskdmp.ini
 	$(MKDIR) $(OUT)/stamp
 	$(TOUCH) $@
 
-out/simh/stamp/pdp10: $(SIMH) start
+out/simh/stamp/pdp10: $(SIMH) start out/simh/boot
 	$(MKDIR) $(OUT)/stamp
 	$(TOUCH) $@
 
-out/pdp10-ka/stamp/pdp10: $(KA10) start
+out/pdp10-ka/stamp/pdp10: $(KA10) start out/pdp10-ka/run
 	$(MKDIR) $(OUT)/stamp
 	$(TOUCH) $@
 
@@ -266,6 +275,12 @@ out/klh10/dskdmp.ini: build/mchn/$(MCHN)/dskdmp.txt Makefile
 	    -e "s/%CHAOSP%/$$cp/" \
 	    -e "s|%CHAOSA%|$$ca|" < $< > $@
 
+out/simh/boot: build/mchn/$(MCHN)/boot
+	cp $< $@
+
+out/pdp10-ka/run: build/mchn/$(MCHN)/run
+	cp $< $@
+
 $(OUT)/syshst/$(H3TEXT): build/$(H3TEXT)
 	$(MKDIR) $(OUT)/syshst
 	$(TEST) $(CHAOS) != no && c="CHAOS $(CHAOS), "; \
diff --git a/build/mchn/DB/boot b/build/mchn/DB/boot
new file mode 100644
index 00000000..e9d1d845
--- /dev/null
+++ b/build/mchn/DB/boot
@@ -0,0 +1,13 @@
+set console wru=034
+set cpu its
+set cpu idle
+set tim y2k
+set dz 8b lines=8
+at dz0 10004
+# VT52
+at dz0 line=7,10018
+# GT40
+at tty line=6,10019
+set rp0 rp06
+at rp0 out/simh/rp0.dsk
+b rp0
diff --git a/build/pdp10-ka/start b/build/pdp10-ka/start
index afab3e3d..e731095c 100755
--- a/build/pdp10-ka/start
+++ b/build/pdp10-ka/start
@@ -94,9 +94,9 @@ EOF
     touch out/pdp10-ka/nohelp
 }
 
-sed -e 's/set dpy enabled/set dpy disabled/' \
+sed -i -e 's/set dpy enabled/set dpy disabled/' \
     -e 's/set wcnsls enabled joystick cscope/set wcnsls enabled joystick/' \
-    < build/mchn/KA/run > out/pdp10-ka/run
+    out/pdp10-ka/run
 
 test -f out/pdp10-ka/nohelp || help
 
diff --git a/build/simh/start b/build/simh/start
index 94f095d6..c6e72fb0 100755
--- a/build/simh/start
+++ b/build/simh/start
@@ -50,5 +50,5 @@ while test -n "$1"; do
     shift
 done
 
-tools/simh/BIN/pdp10 build/simh/boot
+tools/simh/BIN/pdp10 out/simh/boot
 exit 0