diff --git a/src/ca/Makefile b/src/ca/Makefile
index 2f5f79c31..d56852bad 100644
--- a/src/ca/Makefile
+++ b/src/ca/Makefile
@@ -3,72 +3,4 @@ TOP=../..
 
 include $(TOP)/configure/CONFIG
 
-CMPLR = STRICT
-
-#
-#	includes to install from this subproject
-#
-#INC += cadef.h moved header to src/include
-#INC += caerr.h moved header to src/include
-#INC += caeventmask.h moved header to src/include
-INC += caProto.h
-
-#
-#	Contents of library: generic, special and for all systems
-#
-
-# on generic system
-ca_SRCS_DEFAULT = posix_depen.c if_depen.c
-
-# on WIN32 only
-ca_SRCS_WIN32   = windows_depen.c
-
-# on vxWorks only
-ca_SRCS_vxWorks   = vxWorks_depen.c
-
-# on all systems
-ca_SRCS += iocinf.c
-ca_SRCS += service.c
-ca_SRCS += conn.c
-ca_SRCS += flow_control.c
-ca_SRCS += syncgrp.c
-ca_SRCS += access.c
-ca_SRCS += convert.c
-ca_SRCS += test_event.c
-ca_SRCS += bsd_depen.c
-ca_SRCS += repeater.c
-
-#       Library to build:
-#       lib$(LIBRARY).a  or   ..dll/..exp/..lib
-#
-LIBRARY_DEFAULT = ca
-
-PROD_DEFAULT := caRepeater
-PROD_vxWorks := -nil-
-
-#	libs needed to build [TEST]PRODUCT
-PROD_LIBS = ca Com
-ca_DIR = .
-Com_DIR = $(INSTALL_LIB)
-
-SYS_PROD_LIBS_WIN32 = ws2_32 user32 advapi32
-
-TESTPROD_DEFAULT := catime acctst 
-TESTPROD_vxWorks :=
-
-caLib_SRCS = \
-	iocinf.c access.c test_event.c service.c flow_control.c \
-	repeater.c conn.c syncgrp.c bsd_depen.c vxWorks_depen.c \
-	convert.c
-
-LIBRARY_vxWorks = caLib 
-
-include $(TOP)/configure/RULES_BUILD
-
-pcatime : catime.o $(PRODDEPLIBS)
-	$(PURIFY) $(LINK.c) catime.o $(LDLIBS)
-
-pacctst : acctst.o $(PRODDEPLIBS)
-	$(PURIFY) $(LINK.c) acctst.o $(LDLIBS)
-
-#	EOF Makefile.Host
+include $(TOP)/configure/RULES_ARCHS
diff --git a/src/ca/Makefile.Host b/src/ca/Makefile.Host
new file mode 100644
index 000000000..0edad6c12
--- /dev/null
+++ b/src/ca/Makefile.Host
@@ -0,0 +1,62 @@
+
+TOP=../..
+include $(TOP)/configure/CONFIG
+
+CMPLR = STRICT
+
+#
+#	includes to install from this subproject
+#
+INC += caProto.h
+
+#
+#	Contents of library: generic, special and for all systems
+#
+
+# on generic system
+ca_SRCS_DEFAULT = if_depen.c
+
+# on WIN32 only
+ca_SRCS_WIN32   = windows_depen.c
+
+# on vxWorks only
+ca_SRCS_vxWorks   = vxWorks_depen.c
+
+# on all systems
+ca_SRCS += caOsDependent.c
+ca_SRCS += iocinf.c
+ca_SRCS += service.c
+ca_SRCS += conn.c
+ca_SRCS += flow_control.c
+ca_SRCS += syncgrp.c
+ca_SRCS += access.c
+ca_SRCS += convert.c
+ca_SRCS += test_event.c
+ca_SRCS += bsd_depen.c
+ca_SRCS += repeater.c
+
+#       Library to build:
+#       lib$(LIBRARY).a  or   ..dll/..exp/..lib
+#
+LIBRARY = ca
+
+PROD := caRepeater
+
+#	libs needed to build [TEST]PRODUCT
+PROD_LIBS = ca Com
+ca_DIR = .
+Com_DIR = $(INSTALL_LIB)
+
+SYS_PROD_LIBS_WIN32 = ws2_32 user32 advapi32
+
+TESTPROD := catime acctst 
+
+include $(TOP)/configure/RULES_BUILD
+
+pcatime : catime.o $(PRODDEPLIBS)
+	$(PURIFY) $(LINK.c) catime.o $(LDLIBS)
+
+pacctst : acctst.o $(PRODDEPLIBS)
+	$(PURIFY) $(LINK.c) acctst.o $(LDLIBS)
+
+#	EOF Makefile.Host
diff --git a/src/ca/Makefile.Ioc b/src/ca/Makefile.Ioc
new file mode 100644
index 000000000..447bcdcb2
--- /dev/null
+++ b/src/ca/Makefile.Ioc
@@ -0,0 +1,25 @@
+
+TOP=../..
+
+include $(TOP)/configure/CONFIG
+
+CMPLR = STRICT
+
+USR_CFLAGS += -DiocCore
+
+caLib_SRCS += caOsDependent.c
+caLib_SRCS += iocinf.c
+caLib_SRCS += service.c
+caLib_SRCS += conn.c
+caLib_SRCS += flow_control.c
+caLib_SRCS += syncgrp.c
+caLib_SRCS += access.c
+caLib_SRCS += convert.c
+caLib_SRCS += test_event.c
+caLib_SRCS += bsd_depen.c
+caLib_SRCS += repeater.c
+
+LIBRARY = caLib 
+
+include $(TOP)/configure/RULES_BUILD
+