diff --git a/Makefile b/Makefile
index 9e87d4ae..11c89b44 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,12 @@
 EMULATOR ?= simh
+
+# Network configuration for ITS.  Note: for now, the two-letter ITS
+# name is hardcoded to DB, which is short for DistriBution.
+HOSTNAME=DB-ITS.EXAMPLE.COM
 IP=192.168.1.100
 GW=192.168.0.45
 NETMASK=255,255,255,248
+CHAOS=no #Or octal Chaosnet address
 
 # The directores listed in SRC, DOC, and BIN are put on the sources tape.
 SRC = system syseng sysen1 sysen2 sysen3 sysnet kshack dragon channa	\
@@ -55,7 +60,13 @@ start: build/$(EMULATOR)/start
 	ln -s $< $*
 
 build/klh10/stamp: $(KLH10) start build/klh10/dskdmp.ini
-	x=`echo $(IP) | tr . ,`; sed -e "s/%IP%/$$x/" -e 's/%NETMASK%/$(NETMASK)/' < build/klh10/config.203 > src/system/config.203
+	cp=0; ca=0; \
+	test $(CHAOS) != no && cp=1 && ca=$(CHAOS); \
+	x=`echo $(IP) | tr . ,`; \
+	sed -e "s/%IP%/$$x/" \
+	    -e 's/%NETMASK%/$(NETMASK)/' \
+	    -e "s/%CHAOSP%/$$cp/" \
+	    -e "s/%CHAOSA%/$$ca/" < build/klh10/config.203 > src/system/config.203
 	touch $@
 
 build/simh/stamp: $(SIMH) start
@@ -63,10 +74,18 @@ build/simh/stamp: $(SIMH) start
 	touch $@
 
 build/klh10/dskdmp.ini: build/klh10/dskdmp.txt Makefile
-	sed -e 's/%IP%/$(IP)/' -e 's/%GW%/$(GW)/' < $< > $@
+	cp=';'; ca=''; \
+	test $(CHAOS) != no && cp='' && ca='myaddr=$(CHAOS)'; \
+	sed -e 's/%IP%/$(IP)/' \
+	    -e 's/%GW%/$(GW)/' \
+	    -e "s/%CHAOSP%/$$cp/" \
+	    -e "s/%CHAOSA%/$$ca/" < $< > $@
 
 src/syshst/$(H3TEXT): build/$(H3TEXT)
-	sed -e 's/%IP%/$(IP)/' < $< > $@
+	test $(CHAOS) != no && c="CHAOS $(CHAOS), "; \
+	sed -e 's/%IP%/$(IP)/' \
+	    -e 's/%HOSTNAME%/$(HOSTNAME)/' \
+	    -e "s/%CHAOS%/$$c/" < $< > $@
 
 $(KLH10):
 	cd tools/klh10; \
diff --git a/build/h3text.2012 b/build/h3text.2012
index 4539e72f..e387b340 100644
--- a/build/h3text.2012
+++ b/build/h3text.2012
@@ -178,6 +178,6 @@ HOST : 36.21.0.103 : Hamlet.Stanford.EDU,LOTSC : DEC-2060 : TOPS20 :  :
 
 ;;; KLH: All of the rest of this stuff was flushed... see older versions
 ;;; of H3TEXT for the cruft.
-HOST : %IP% : DB-ITS.EXAMPLE.COM, DB : PDP-10 : ITS : :
+HOST : %CHAOS%%IP% : %HOSTNAME%, DB : PDP-10 : ITS : :
 
 
\ No newline at end of file
diff --git a/build/klh10/config.203 b/build/klh10/config.203
index fac2ed8f..a1a56df7 100644
--- a/build/klh10/config.203
+++ b/build/klh10/config.203
@@ -989,6 +989,10 @@ DEFOPT IMPUS==100.	; IMP net host number (old-style) (100 octal)
 DEFOPT IMPUS3==<IPADDR %IP%>	; IP address
 DEFOPT NM%IMP==<IPADDR %NETMASK%>	; Subnet mask
 DEFOPT PKTTRC==-1	;Packet tracing code enabled
+DEFOPT CHAOSP==%CHAOSP% ;Has CHAOS net
+DEFOPT MYCHAD==%CHAOSA% ;CHAOS net address
+DEFOPT NINDX==50.       ;Number of indices
+DEFOPT CH11P==%CHAOSP%  ;CHAOS net goes through Unibus
 
 DEFINE ITSIRP BODY
 IRPS ITS,,[DB]
diff --git a/build/klh10/dskdmp.txt b/build/klh10/dskdmp.txt
index 28ff5fc8..3bbdefb7 100644
--- a/build/klh10/dskdmp.txt
+++ b/build/klh10/dskdmp.txt
@@ -20,7 +20,7 @@ devdef imp  ub3   lhdh   addr=767600 br=6 vec=250 ipaddr=%IP% gwaddr=%GW%
 ; Dummy definitions.  Only one DZ is still (apparently) needed.
 devdef dz0  ub3   dz11   addr=760010 br=5 vec=340
 ;devdef dz1  ub3   dz11   addr=760020 br=5 vec=350
-;devdef chaos ub3  ch11   addr=764140 br=5 vec=270
+%CHAOSP%devdef chaos ub3  ch11   addr=764140 br=6 vec=270 %CHAOSA%
 
 ; Define new HOST device hackery
 ;devdef idler ub3 host addr=777000