diff --git a/config/CONFIG.Host.LynxOS b/config/CONFIG.Host.LynxOS
new file mode 100644
index 000000000..a13c54c65
--- /dev/null
+++ b/config/CONFIG.Host.LynxOS
@@ -0,0 +1,58 @@
+# CONFIG.Host.LynxOS
+#
+#  This file is maintained by the EPICS community.
+#  Sites may override these definitions in CONFIG_SITE.Host.LynxOS
+ 
+ARCH_CLASS = LynxOS
+
+# Include definitions common to all Unix archs
+include $(EPICS_BASE)/config/CONFIG.Host.UnixCommon
+
+AR = ar -rc
+ARCMD = $(AR) $@
+RANLIB = ranlib -t
+
+
+
+# Configure OS vendor C compiler
+ACC_ANSI = $(ACC) -ansi -mposix -D_X86_ 
+ACC_STRICT = $(ACC) -ansi -mposix -D_X86_ -pedantic
+ACC_TRAD = $(ACC)
+ACC_WARN_YES = -Wall 
+ACC_WARN_NO =  -w
+ACC_OPT_YES =  -O
+ACC_OPT_NO = -g
+ACC_SFLAGS_YES = -Bstatic
+ACC_SFLAGS_NO=
+ACC_SLIBS_YES =
+ACC_SLIBS_NO=
+ACC_SHRLIB_CFLAGS_YES = 
+ACC_SHRLIB_LDFLAGS_YES =
+
+
+
+# Configure OS vendor C++ compiler
+CCC_NORMAL = $(CCC)
+CCC_STRICT = $(CCC)
+CCC_TEMPL_INST_FLAG = -pedantic -mposix -D_X86_ -DEXPL_TEMP
+CCC_WARN_YES = -Wall
+CCC_WARN_NO = -w
+CCC_OPT_YES =  -O
+CCC_OPT_NO = -g
+CCC_SFLAGS_YES = -Bstatic
+CCC_SFLAGS_NO=
+CCC_SLIBS_YES = 
+CCC_SLIBS_NO=
+CCC_DEPENDS_FLAG = -pedantic -mposix -D_X86_ 
+
+
+# added smh 6/5/98 : when building fdmgr - seems to use this not ACC
+# in effect this overides orig def in CONFIG_COMMON :
+# which is GCC_STRICT = $(GCC) -ansi -pedantic
+GCC_STRICT = $(GCC)
+G++_STRICT = $(G++) -Wtraditional -mposix -D_X86_ -DEXPL_TEMP
+
+
+
+ARCH_DEP_CFLAGS = -DLynxOS -mposix -D_X86_ 
+ARCH_DEP_LDFLAGS = -lc -lbsd -lnsl -lm -lposix4d9 -llynx
diff --git a/config/CONFIG.LynxOS b/config/CONFIG.LynxOS
new file mode 100644
index 000000000..f18c11ae6
--- /dev/null
+++ b/config/CONFIG.LynxOS
@@ -0,0 +1,136 @@
+# $Id$
+#
+# This file contains definitions for Vx builds
+
+#--------------------------------------------------
+# operating system class (include/os/<os_class>)
+OS_CLASS = LynxOS
+
+lynx_pc486 =YES
+
+CC = gcc
+CXX = g++
+
+#--------------------------------------------------
+# vxWorks directory definitions
+
+# The definitions VX_DIR, VX_GNU, GNU_DIR and GNU_LIB
+# can be overridden for specific host architectures
+# by creating a CONFIG_SITE.Vx.<host_arch> file with
+# the override definitions.
+ 
+# Tornado directory definitions
+VX_CONFIG_DIR_YES =
+VX_INCLUDE_YES =
+VX_GNU_YES =
+VX_GNU_BIN_YES =
+VX_GNU_LIB_YES =
+
+
+# pre Torando directory definitions
+VX_CONFIG_DIR_NO =
+VX_INCLUDE_NO =
+VX_GNU_NO =
+VX_GNU_BIN_NO =
+ 
+# directory definitions
+VX_DIR =
+VX_CONFIG_DIR =
+VX_INCLUDE =
+VX_GNU = 
+
+GNU_BIN = /usr/local/bin
+GNU_LIB = /usr/local/lib
+
+#--------------------------------------------------
+# VxWorks command definitions
+
+#GCC = $(GNU_BIN)/cc$(CMPLR_SUFFIX) -B$(GNU_LIB)/gcc-lib/ -nostdinc
+#AR = $(GNU_BIN)/ar$(CMPLR_SUFFIX)
+#CPP = $(GNU_BIN)/cpp$(CMPLR_SUFFIX) -nostdinc
+#RANLIB = $(GNU_BIN)/ranlib$(CMPLR_SUFFIX)
+#LD = $(GNU_BIN)/ld$(CMPLR_SUFFIX) -r
+
+AR = ar -rc
+ARCMD = $(AR) $@
+RANLIB = ranlib -t
+GCC = gcc 
+CPP = cpp
+LD = ld -r
+
+
+#--------------------------------------------------
+# Tornado C++ crosscompiler definitions
+
+#CPLUSPLUS_YES = G++
+#G++ = $(GNU_BIN)/cc$(CMPLR_SUFFIX) -B$(GNU_LIB)/gcc-lib/ -nostdinc
+#LD_G++ = $(GNU_BIN)/ld$(CMPLR_SUFFIX) -r
+#NM = $(GNU_BIN)/nm$(CMPLR_SUFFIX)
+#MUNCH = $(GNU_BIN)/munch
+
+CPLUSPLUS_YES = g++ -DLynxOS -DLynxOS_pc486 -mposix -D_X86_ -DEXPL_TEMP
+G++ = g++ -DLynxOS -DLynxOS_pc486 -mposix -D_X86_ -DEXPL_TEMP
+LD_G++ = ld -r
+NM = nm
+
+#--------------------------------------------------
+# Pre Tornado C++ crosscompiler definitions
+# These are pre tornado definitions for Hideos builds (defined for 68k only)
+
+#CPLUSPLUS_NO = CCC
+#CCC = $(GNU_DIR)/bin/sun3-g++ -B$(GNU_DIR)/lib/gcc-lib/ -nostdinc -DEXPL_TEMPL
+#LD_CCC = $(GNU_DIR)/bin/sun3-ld $(OLD_ARCH_DEP_LDFLAGS) -r
+
+CPLUSPLUS_NO = g++ -DLynxOS -DLynxOS_pc486 -mposix -D_X86_ -DEXPL_TEMP
+CCC = g++ -DLynxOS -DLynxOS_pc486 -mposix -D_X86_ -DEXPL_TEMP
+LD_CCC = ld -r
+
+CCC_NORMAL = $(CCC) $(OLD_ARCH_DEP_CFLAGS)
+CCC_STRICT = $(CCC) -ansi -pedantic -Wall -traditional $(OLD_ARCH_DEP_CFLAGS)
+CCC_TRAD = $(CCC) -traditional $(OLD_ARCH_DEP_CFLAGS)
+CCC_TEMPL_INST_FLAG = -DEXPL_TEMP
+CCC_WARN_YES = -Wall
+CCC_WARN_NO = -w
+CCC_OPT_YES = -O
+CCC_OPT_NO = -g
+CCC_DEPENDS_FLAG =  -pedantic -DLynxOS -DLynxOS_pc486 -mposix -D_X86_
+CPU = i486
+OS = lynxos
+OLD_ARCH_DEP_CFLAGS = -DLynxOS -DLynxOS_pc486 -mposix -D_X86_
+#	 --no-builtin -Wa,"-m68040" -DOS_EQ_$(OS) \
+#	-DBOARD_EQ_$(BOARD) -DCPU_EQ_$(CPU) -DBOARD=$(BOARD)
+OLD_ARCH_DEP_LDFLAGS = -mposix -lc -lbsd -lnsl -lm -lposix4d9 -llynx
+#	 -Ur -N -T$(EPICS_BASE_BIN)/vxldscript.MRI
+
+#--------------------------------------------------
+# C compiler definitions  
+ANSI = gcc -ansi
+
+#--------------------------------------------------
+# Command definitions
+CPLUSPLUS = g++
+#	 $(CPLUSPLUS_$(TORNADO))
+LD_CXX = ld -r
+#	 $(LD_$(CPLUSPLUS))
+
+#--------------------------------------------------
+# Operating system flags
+OP_SYS_INCLUDES =
+#	 -I$(VX_INCLUDE)
+OP_SYS_CFLAGS =  -DLynxOS -DLynxOS_pc486 -mposix -D_X86_
+#		-DvxWorks -DV5_vxWorks -fno-builtin 
+OP_SYS_LDFLAGS = -DLynxOS -DLynxOS_pc486 -mposix -D_X86_
+OP_SYS_LDLIBS = -lc -lbsd -lnsl -lm -lposix4d9 -llynx
+
+#--------------------------------------------------
+# Optimization flag overrides
+GCC_OPT_YES = -O	
+#	2 -fstrength-reduce
+G++_OPT_YES = -O
+#	2 -fstrength-reduce
+
+#--------------------------------------------------
+# Link definitions
+LINK.c = $(LD) $(LDFLAGS) -o
+LINK.cc = $(LD_CXX) $(LDFLAGS) -o
+
diff --git a/config/CONFIG_HOST_ARCH.LynxOS b/config/CONFIG_HOST_ARCH.LynxOS
new file mode 100644
index 000000000..4d9bd2216
--- /dev/null
+++ b/config/CONFIG_HOST_ARCH.LynxOS
@@ -0,0 +1,9 @@
+#  CONFIG_HOST_ARCH.LynxOS
+#
+# Override values in CONFIG.LynxOS
+
+# Include definitions common to all Unix archs
+include $(EPICS_BASE)/config/CONFIG_HOST_ARCH.UnixCommon
+
+WIND_HOST_TYPE = LynxOS
+
diff --git a/config/CONFIG_SITE b/config/CONFIG_SITE
index 02eba71b2..cc9f9bd39 100644
--- a/config/CONFIG_SITE
+++ b/config/CONFIG_SITE
@@ -20,6 +20,7 @@
 #	sgi
 #	Linux
 #	WIN32
+#	LynxOS
 #
 #  HOST_ARCH now an environment variable
 #  HOST_ARCH=$(shell /usr/local/epics/startup/HostArch)
diff --git a/config/CONFIG_SITE.Host.LynxOS b/config/CONFIG_SITE.Host.LynxOS
new file mode 100644
index 000000000..6fe296b27
--- /dev/null
+++ b/config/CONFIG_SITE.Host.LynxOS
@@ -0,0 +1,15 @@
+#
+# $Id$
+#
+# Site Specific Configuration Information
+# Only the local epics system manager should modify this file
+
+# APS overrides of definitions 
+
+GCC = gcc
+G++ = g++
+CC = gcc
+CCC = g++
+ACC = gcc
+PLUSPLUS = g++
+CXX = g++
diff --git a/src/gdd/aitTypes.h b/src/gdd/aitTypes.h
index f66ecea73..8583a7248 100644
--- a/src/gdd/aitTypes.h
+++ b/src/gdd/aitTypes.h
@@ -8,6 +8,9 @@
  * $Id$
  *
  * $Log$
+ * Revision 1.8  1998/06/16 03:10:51  jhill
+ * added sgi support
+ *
  * Revision 1.7  1998/04/16 21:16:35  jhill
  * removed redundant solaris test
  *
@@ -88,7 +91,7 @@ typedef	struct {
 #endif
 
 #ifndef vxWorks
-#if (_POSIX_C_SOURCE < 3) && !defined(SOLARIS) && !defined(HP_UX) && !defined(linux) &&!defined(sgi)
+#if (_POSIX_C_SOURCE < 3) && !defined(SOLARIS) && !defined(HP_UX) && !defined(linux) && !defined(sgi) && !defined(LynxOS)
 
 struct timespec
 {
diff --git a/src/libCom/osi/os/LynxOS/osdSock.h b/src/libCom/osi/os/LynxOS/osdSock.h
new file mode 100644
index 000000000..95be0483a
--- /dev/null
+++ b/src/libCom/osi/os/LynxOS/osdSock.h
@@ -0,0 +1,73 @@
+
+/*
+ * LynxOS specific socket include
+ */
+
+#ifndef osiSockH
+#define osiSockH
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <errno.h>
+
+#include <sys/types.h>
+#include <sys/param.h> /* for MAXHOSTNAMELEN */
+#include <sys/time.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <netdb.h>
+#include <unistd.h> /* close() and others */
+ 
+/*
+ * as far as I can tell there is no header file for these
+ */
+int gethostname(char *name, int namelen);
+int sethostname(char *name, int namelen);
+
+#ifdef __cplusplus
+}
+#endif
+ 
+typedef int SOCKET;
+#define INVALID_SOCKET (-1)
+#define SOCKERRNO errno
+#define SOCKERRSTR (strerror(errno))
+#define socket_close(S) close(S)
+
+#if 1
+	/* 
+	 * only for LynxOS v2.4.0 
+	 */
+#	define socket_ioctl(A,B,C) ioctl(A,B,(char *)C)
+#else
+#	define socket_ioctl(A,B,C) ioctl(A,B,C)
+#endif
+
+typedef int osiSockIoctl_t;
+
+#define FD_IN_FDSET(FD) ((FD)<FD_SETSIZE&&(FD)>=0)
+
+#define SOCK_EWOULDBLOCK EWOULDBLOCK
+#define SOCK_ENOBUFS ENOBUFS
+#define SOCK_ECONNRESET ECONNRESET
+#define SOCK_ETIMEDOUT ETIMEDOUT
+#define SOCK_EADDRINUSE EADDRINUSE
+#define SOCK_ECONNREFUSED ECONNREFUSED
+#define SOCK_ECONNABORTED ECONNABORTED
+#define SOCK_EINPROGRESS EINPROGRESS
+#define SOCK_EISCONN EISCONN
+#define SOCK_EALREADY EALREADY
+#define SOCK_EINVAL EINVAL
+#define SOCK_EINTR EINTR
+#define SOCK_EPIPE EPIPE
+
+#define INADDR_LOOPBACK 0x7F000001
+
+#endif /*osiSockH*/
+