1: Add:
	-DRUNNING_IP

   to the Makefile CFLAGS line and rebuild cl_main.o if it's already
   been compiled.

2: Add:

	IPOBJS=	ip_funcs.o ip_main.o ip_read.o ip_screen.o ip_term.o

   after the other object lists in the Makefile.

3: Add
	$(IPOBJS)

   to the end of the NVIALL= line in the Makefile.

4: Add:

	# Vi IP sources.
	ip_funcs.o: $(srcdir)/ip/ip_funcs.c
		$(CC) $(CFLAGS) $?
	ip_main.o: $(srcdir)/ip/ip_main.c
		$(CC) $(CFLAGS) $?
	ip_read.o: $(srcdir)/ip/ip_read.c
		$(CC) $(CFLAGS) $?
	ip_screen.o: $(srcdir)/ip/ip_screen.c
		$(CC) $(CFLAGS) $?
	ip_term.o: $(srcdir)/ip/ip_term.c
		$(CC) $(CFLAGS) $?

   at the end of the Makefile.

5: Remove cl_main.o if it exists, and make nvi.

6: Go to ip_cl and change the entries in the Makefile to reflect
   where the nvi binary was just built.

7: Build ip_cl.

8: Enter ip_cl and you should be running vi over a pipe.