Sun-3 with SunOS
Sun-4 with SunOS

   Works.
   Since Sun has broken their linker again in SunOS 4.1, you must
   specify the full pathnames of the relevant X11 libraries in the top
   level Makefile.

VAX with 4.3BSD or Ultrix

   Works.
   The C compiler can't handle void* correctly, therefore GENERIC must be
   defined as char* in the top level Makefile.

NeXT

   Works.  "dump" is currently not supported on the NeXT.
   A dynamically loaded object file cannot reference symbols that
   have been defined by a previously loaded file (this is a mis-feature
   of the rld(3)-functions).

Integrated Solutions 680x0 with 4.2BSD or 4.3BSD

   Works, but I haven't tested the X11 interface.
   You may have to define GENERIC as char* in the top level Makefile.
   You may have to add -X23 to the CFLAGS (for the Greenhills cc).

Intel 80386 with System V Release 3 or System V/386 (Interactive)

   Works, but I haven't tested the X11 interface.
   Under Interactive Unix you must not compile with -O.
   Dynamic loading of object files is not supported under System V,
   since the linker doesn't support incremental linking.

IBM RT with AOS

   Zalman Stern <zs01+@andrew.cmu.edu> reported that it works on
   the IBM RT.

Sequent Symmetry

   Richard Kuhns <newton.physics.purdue.edu!sawmill!rjk> and
   On G. Paradise <oparadis@erseq.oracle.com> reported that Elk works
   on the Sequent.

   Several people reported that the GNU linker has to be used for
   dynamic loading.  Check the pathname of the GNU linker in the
   file src/load.c (the default is /usr/local/lib/gcc-ld).

HP 9000 Series 300
 
   Works.
   The X11 extension works with MIT's X11 Release 4.
   Before calling "make", set your SHELL environment variable to /bin/sh.
   The "ALIGN redefined" warnings of the C compiler can be ignored.

HP 9000 Series 800

   Works (but only the `portable' version).
   The X11 extension works with MIT's X11 Release 4.
   Before calling "make", set your SHELL environment variable to /bin/sh.
   Dynamic loading of object files doesn't work due to a bug in HP's
   linker.  The bug will probably be fixed in the next release of HP-UX.
   C compiler messages like "Subspace characteristics may not be changed
   after first definition" can be ignored.

Sony NEWS 1750/1850 (68k)

   Works.

DECStation 3100
Sony NEWS 3860
(and probably other MIPS-based machines)

   MIPS-based machines don't seem to have an alloca() that can be used
   with Elk.  Therefore you must either install the portable version or
   use the GNU C-compiler (gcc).

   In addition, you must link the executable in a way that the data
   segment starts at 0x800000 (this number must correspond to the value
   of POINTER_CONSTANT_HIGH_BITS in src/config.h).  This can be achieved
   by the cc-option -Wl,-D,800000.

   There are a couple of problems with gcc on MIPS-based machines:  
   
      o it doesn't recognize -Wl,-D,80000.  Thus, Elk must be linked with
	cc.  You can do the following:

	   make TARGETS=src CC=gcc
	   rm src/scheme
	   make TARGETS=src
	   make CC=gcc

      o older versions of gcc may not correctly compile files that use
	varargs.  In this case src/error.c and src/print.c must be compiled
	with cc

      o on the DECStation 3100, gcc may barfs over src/bignum.c (this is a
	bug in gcc).  In this case you must gcc -S bignum.c, edit bignum.s
	and replace the symbol Infinity by 1e308, and then gcc -c bignum.s


   Incremental linking currently doesn't work on MIPS-based machines.
   /bin/ld complains about "gp relocation out-of-range errors"; so far
   nobody could tell me what exactly this means.

   Therefore I recommend to remove CAN_LOAD_OBJ from src/config.h and
   add #define INIT_OBJECTS.  You can then create a statically linked
   interpreter with your extensions by means of the shell script
   src/link-scheme.  For instance, to create an interpreter with the
   X11 extensions, call

      cd src
      link-scheme xscheme ../lib/unix.o ../lib/{xlib,xt,xaw}/*.o
	-lXaw -lXext -lXmu -lXt -lX11


X Window System

   X11 Release 3 is no longer supported.  You need either X11R4 or
   X11R5 to use the Elk/X11 interface.  If you want to use Elk with
   X11R4 do the following:

       cd lib/xaw; cp Makefile.x11r4 Makefile


OSF/Motif widgets

   Motif 1.0 is no longer supported.  You need Motif 1.1 to use the
   Elk/Motif interface.  If you are running X11R5 make sure that it
   has been compiled with the symbol MotifBC set to YES in site.def.
