Changing from EDWIN Version 4 to EDWIN Version 5
================================================

It is hoped that Version 4 of EDWIN can be withdrawn before the start of the
new term.  Version 5 has been running in parallel with version 4, and it has
recently had the final planned updates done to it, and will now be ported to
all other systems.  The following timescales are envisaged -

VAX : (Version 4 of EDWIN is the one using the logical name $EDWIN)
      (Version 5 of EDWIN is the one using the logical name EDWIN_DIR)
      (Ie. to use Version 5 change %include "$edwin:.inc" to
                                   %include "Edwin_dir:specs.inc")
      (A complete list of Include files are given below.)

      The file $EDWIN:.INC will be removed on Monday 17th Sept.
      This allows people to link existing programs, but not re-compile them.

      The file $EDWIN:.OPT will be removed on Thurday 20th Sept.
      Existing programs will still run, but users can no longer link with
      version 4 of EDWIN.

      The sharable library will be removed during the following week after
      checks to see that people are not depending on it.

APM : It is planned to introduce the new version when the new operating system
      is released.  Further details of the changeover will be made using the APM
      alert mechanism.

EMAS : A pre-release version will be available by the end of the week.
       The versions in ECSLIB and CONLIB would be updated after this is tested.

Please contact Gordon Hughes if you have any queries about the schedule.

-------------------------------------------------------------------------------

The major visible change is that all the Imp procedures conform to the VMS
naming conventions (ie. start EDWIN_) and these should be declared using the
appropriate include files.  The following name changes have happened -

       CURSOR        -> REQUEST INPUT                 ( 'Think GKS' )
       DRIVE DEV     -> DRIVE DEVICE
       D CURSOR      -> REQUEST DEVICE
       DEVICE NAME   -> DEVICE DATA_NAME
       DEVICE        -> DEVICE DATA_DEV NO

** NB: The internal logical device numbers (ie. DEVICE) has changed, so that
       people who have written machine specific hacks with constants written
       into them won't get them to work any more.  If you must know about a
       device then the constants in the include file CONSTS file should be used.

       Two new pieces of information which can be used to write more portable
       programs are -

       DEVICE DATA_UNITS PER CM   - Units per cm on a plotter, otherwise 0
       DEVICE DATA_MAX COLOUR     - Number of Colours available (0 => 1!)

The following are the official names of the Include files -

           VAX/VMS                   APM                       EMAS

   EDWIN_DIR:CONSTS.INC       EDWIN:CONSTS.INC            ECSLIB.EDWIN_CONSTS
   EDWIN_DIR:CONSTS.PAS       EDWIN:CONSTS.PAS            ECSLIB.EDWIN_PCONSTS
   EDWIN_DIR:SPECS.INC        EDWIN:SPECS.INC             ECSLIB.EDWIN_SPECS
   EDWIN_DIR:SPECS.PAS        EDWIN:SPECS.PAS             ECSLIB.EDWIN_PSPECS
   EDWIN_DIR:TYPES.INC        EDWIN:TYPES.INC             ECSLIB.EDWIN_TYPES
   EDWIN_DIR:TYPES.PAS        EDWIN:TYPES.PAS             ECSLIB.EDWIN_PTYPES
   EDWIN_DIR:SHAPES.INC       EDWIN:SHAPES.INC            ECSLIB.EDWIN_SHAPES
   EDWIN_DIR:SHAPES.PAS       EDWIN:SHAPES.PAS            ECSLIB.EDWIN_PSHAPES
   EDWIN_DIR:TXSTACK.INC      EDWIN:TXSTACK.INC           ECSLIB.EDWIN_TXSTACK
   EDWIN_DIR:TXSTACK.PAS      EDWIN:TXSTACK.PAS           ECSLIB.EDWIN_PTXSTACK

A major change on VMS (ECSVAX anyway!) is that you just say LINK file to link,
rather than having to state the library.  Some examples of using the geometric
routines and transformation stack from Pascal, and the general Edwin routines
from Fortran can be found in the files Edwin_dir:*demo.*

Please inform Gordon Hughes (JGH@ECSVAX) of any problems which you experience.

Gordon Hughes   11th Sept 1984
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