diff --git a/configure/os/CONFIG_COMPAT b/configure/os/CONFIG_COMPAT
new file mode 100644
index 000000000..50fe6e23f
--- /dev/null
+++ b/configure/os/CONFIG_COMPAT
@@ -0,0 +1,22 @@
+#
+# $Id$
+#
+# Convert old HOST_ARCH environment variable to
+# new EPICS_HOST_ARCH environment variable 
+
+#Syntax:
+# ARCH_<host_arch> = <epics_host_arch>
+ARCH_solaris = solaris-sparc
+ARCH_sun4 = sun4-sparc
+ARCH_Linux = linux-x86
+ARCH_WIN32 = win32-x86
+ARCH_hp700 = hpux-m68k
+ARCH_hp700 = osf-alpha
+
+ifndef EPICS_HOST_ARCH
+ifdef HOST_ARCH
+EPICS_HOST_ARCH = $(firstword $(ARCH_$(HOST_ARCH)) $(HOST_ARCH))
+else 
+EPICS_HOST_ARCH = unsupported
+endif
+endif