Enter your search terms Submit search form
	Web pdp-10.trailing-edge.com

         LINK.DOC: LINK Version 5.1(2030) 25 Jan 83




Copyright (C) 1983 Digital Equipment  Corporation,  Maynard,
MA.





This software is furnished under a license and may  be  used
and copied only in accordance with the terms of such license
and with the inclusion of the above copyright notice.   This
software  or any other copies thereof may not be provided or
otherwise made available to any other person.  No  title  to
and ownership of the software is hereby transferred.



The information  in  this  software  is  subject  to  change
without  notice  and should not be construed as a commitment
by Digital Equipment Corporation.



Digital assumes no responsibility for the use or reliability
of  its  software  on  equipment  which  is  not supplied by
Digital.

                                                      Page 2


1.0  INTRODUCTION



LINK  is  the  linking  loader  for  the  DECsystem-10   and
DECSYSTEM-20.  LINK 5.1 is a maintenance release of LINK for
the DECSYSTEM-20 and a development release of LINK  for  the
DECsystem-10.   LINK  5.1 includes a number of new features,
internal changes, and bug fixes.

LINK 5.1 supercedes all previous versions.   It  runs  under
all  supported  monitors,  and has been tested under TOPS-10
7.01A, and under TOPS-20 releases 4.1, 5.0 and 5.1.

LINK is documented  in  the  LINK  Reference  Manual.   This
manual  is  available  as  part  of  volume 4 of the TOPS-20
Software Notebooks, or it can be ordered separately as order
number AA-4183C-TM.




2.0  INSTALLATION



To install LINK, move the files LINK.EXE and  OVRLAY.REL  to
PS:<SUBSYS>.    The   LINK.HLP   file  should  be  moved  to
PS:<HELP>.





3.0  REBUILDING LINK


All the files required to rebuild LINK are included  on  the
tape:   sources,  command  files,  and  a control file.  The
control  file  LINK.CTL  reassembles  the  LINK  and  OVRLAY
modules  and  re-links LINK.  It requires a time limit of 20
minutes.



4.0  RECENT CHANGES AND NEW FEATURES


     1.  Users converting existing FORTRAN  applications  to
         FORTRAN  77 as well as those writing new FORTRAN 77
         programs  will  be  able  to  use   the   load-time
         typechecking facility in LINK.  Use the /ERRORLEVEL
         or  /LOGLEVEL  switch  to  get  messages   flagging
         inconsistencies in the number and kind of arguments
         being passed to a subroutine or function.

                                                      Page 3


     2.  The  /PLTTYP  switch  permits  a  user  to  specify
         whether  a  spooled  disk  file  should  be plotter
         format or printer format.

     3.  In LINK 5.0 a quota violation when writing .TMP  or
         .EXE  files  would  cause  LINK-20 to issue a fatal
         non-continuable error message.  In this new version
         LINK-20  will try to expunge the directory in which
         the output file is being written and continue after
         the  quota  violation  is detected.  If this is not
         possible the fatal message is issued.




5.0  RESTRICTIONS


     1.  If a program is being structured  to  use  overlays
         and  there  is  a  very  large  number  of  symbols
         associated with a particular overlay link, LINK may
         issue  an  ?LNKMEF  memory expansion error if a map
         file is requested.  If this occurs use  the  switch
         /NOLOCAL on some or all modules being loaded to cut
         back the number of symbols.

     2.  LINK currently expects type 1120-1127 blocks to use
         routine  names that can be translated to SIXBIT and
         which are unique in the first six characters.  Also
         this  routine  name  must be a global symbol.  Type
         mismatch warnings also display only the  first  six
         SIXBIT  characters  of  the global symbol name.  No
         currently supported language is  affected  by  this
         deficiency.

     3.  The .TPLOD  bit  defined  for  the  type  1120-1127
         blocks   is   not  currently  used.   No  currently
         supported language is affected by this deficiency.

     4.  There are conflicts between the  documentation  and
         the implementation of type 1070 blocks:
         Fullword  addition  is  used  for  additive  symbol
         fixups.

         Right halfword addition is used for other  additive
         fixups.

         Fullword fixups are done when thirty-bit fixups are
         requested.

         No currently  supported  language  is  affected  by
         these errors.

                                                      Page 4


     5.  The .PVMEM word of the program data vector  is  not
         initialized.

     6.  Multiple  program  data   vectors   are   not   yet
         supported.

     7.  LINK-20  ignores  the  /DEBUG:DDT   and   /TEST:DDT
         switches   when   loading  an  extended  addressing
         program.   Use  the  EXEC  command  DDT  with   the
         /USE-SECTION  switch  to merge DDT into the program
         image.

     8.  Type 1070 blocks lose the  section  number  of  the
         defining   symbol   during   processing  of  30-bit
         additive fixups.

     9.  There are inconsistencies in  the  usage  of  PSECT
         indices in old and new .REL blocks.

    10.  .REL  files  cannot  be  read  from   non-directory
         devices.   This  includes magtapes, cards and paper
         tape.  Transfer these files to disk before  linking
         them.

    11.  FORTRAN  Character-to-hollerith   fixups   do   not
         default the section number of the ASCIZ string when
         extracting it from the Y field of the  descriptor's
         byte pointer.

    12.  LINK does not flag 18-bit truncation  of  a  30-bit
         value  when  doing a symbol table fixup or a polish
         fixup.

    13.  LINK does not type its exit messages  when  loading
         an extended addressing program.