Cover Letter for VAX-11 RSX Version 2.5

          AV-KS02D-TE


          Dear VAX-11 RSX Customer,

          VAX-11 RSX Version 2.5 is a maintenance release that
          corrects problems found in previous versions of VAX-11
          RSX and provides the following new features:

          o  Support for VMS Version 5.4

          o  New FSS$, PFCS$, and PRMS$ system directives

          o  Common File Control Services (FCS)

          o  MCR support for most DCL commands

          Please refer to the Preface of the VAX-11 RSX Version
          2.5 Installation Guide and Release Notes and this
          cover letter for a complete list of changes and new
          restrictions for this release.

                                    NOTE

             VAX-11 RSX Version 2.5 is required for VMS Ver-
             sion 5.4 or later systems. Earlier versions of
             VAX-11 RSX are not supported on VMS Version 5.4
             or later systems.

             VAX-11 RSX Version 2.5 also supports VMS system
             versions earlier than 5.4. For a complete discus-
             sion of version compatibility and restrictions,
             please refer to Section 1.1 in the VAX-11 RSX
             Version 2.5 Installation Guide and Release Notes.

          The following information was too recent to be included
          in the VAX-11 RSX Version 2.5 Installation Guide and
          Release Notes:

          o  Search lists

 


                                                           Page 2



             A problem with the way VAX-11 RSX handled multival-
             ued logical names (search lists) has been corrected.
             VAX-11 RSX supports the use of a search list logical
             name in place of a device name in a file specifica-
             tion if both of the following conditions exist:

             -  All the equivalence names of the search list
                translate to either a device name or a device
                name and a rooted directory

             -  A $$n logical name has been defined for the
                search list

             © Digital Equipment Corporation. 1990. All rights
             reserved.

 


                                                           Page 3



          o  Task overlay loading restriction

             VAX-11 RSX does not support running tasks that
             contain both memory-resident and disk-resident
             overlays. However, because of an overlay cache
             implemented by VAX-11 RSX, tasks built with either
             all memory-resident or all disk-resident overlays
             offer comparable performance.

             The VAX-11 RSX Version 2.5 Installation Guide and
             Release Notes incorrectly state that this problem
             was corrected for Version 2.5. Because of technical
             complications, we regret being unable to include
             support for running tasks with both memory-resident
             and disk-resident overlays for this release.

          o  TKB /EX restriction

             VAX-11 RSX does not support running tasks that are
             built with the Task Builder /EX switch. This switch
             was added in RSX-11M-PLUS Version 4.3 to allow
             tasks built with memory resident overlays to use
             the Extend Task (EXTK$) directive.

          Installing FORTRAN IV or FORTRAN-77

          Prior to installing FORTRAN-IV Version 2.8 or FORTRAN-
          77 Version 5.3 or 5.4, ensure that previous versions of
          these products are deleted from SYS$COMMON:[SYSEXE].
          You cannot access the new version of the FORTRAN prod-
          uct, which is located in LB:[1,54], if the old version
          remains in SYS$COMMON:[SYSEXE].