
                                                            
 
 
                     RELEASE NOTES FOR
                     =================
 
                 SWEDISH PASCAL VERSION 5+
                 =========================
 
 
 
 
 
 
Originally   obtained  from  John  Barr,  DECUS  Pascal  SIG
chairman. He got it from  Seved  Torstendahl  in  Stockholm.
Modified, corrected and repackaged by:
 
                Gerry Pelletier
                Transport Canada (TARI)
                Transport Canada Bldg.
                Place de Ville,
                Ottawa, Ontario, Canada
                K1A 0N8                 613-994-2378
 
 
 
 
 
 
 
 
 
 
                          CONTENTS
                          ========
 
    1. Introduction................................ 1
    2. Files and their contents.................... 2
    3. Installing Pascal........................... 6
      3.1 Preparing PASLIB......................... 6
      3.2 Preparing PAS compiler................... 7
      3.3 Preparing PAZ compiler................... 8
    4. The Heap and what to do with it.............10
    5. Bugs........................................12
    6. Incomplete implementation...................12
    7. Crosscompiler on DEC-10.....................13
 
 
 
 
 
 
                                                            

                                                            
 
 
1.  Introduction
================
 
 
The  version  5  Swedish Pascal for PDP-11 as distributed by
DECUS was chosen as an interim compiler for the  development
of  a  large  software  project  at  Transport  Canada. Upon
encountering severe bugs and limitations of this package, we
embarked on a program of maintaining it ourselves. This  was
made  easier  by the inovation of a method for compiling the
main source module of  the  compiler  on  a  PDP-11  whereas
previously,  this could only be done by cross compiling on a
DEC system 10.
 
To date, there have been about 53 modifications made to  the
compiler  and  runtime  routines.  Many  of these constitute
corrections for bugs and other deficiencies,  but  some  are
enhancements  and  extensions.  A few of these are worthy of
note here:
 
  - Type CHAR has  been  redefined  to  cover  the  subrange
    chr(0)    to    chr(255)    (it    was    ' '..'_'    or
    chr(32)..chr(95)). This is more useful in an environment
    with modern data terminals  where  non-printing  control
    characters are just as common as printing characters.
 
  - Line  addresses are displayed instead of line numbers in
    PASRUN  error  messages.  This  is  an  easier  way   of
    identifying  error locations in programs made up of many
    separatly compiled procedures.
 
  - TTY file is the default standard  file  in  a  separatly
    compiled procedure (see section 2.6 in the user manual).
 
  - Files no longer have to be declared in the main program.
 
  - Bugs  were  corrected  which  make  possible  the use of
    string parameters (see section 2.13 of user manual).
 
 
 
 
 
 
 
 
 
 
 
 
29-NOV-79                  - 1 -                            

                                                            
 
 
2.  Files and their contents
============================
 
 
 
The release tape has all files divided into 4 distinct UICs:
 
      [76,100] - documentation and runtime library PASLIB,
      [76,101] - the PAS version of the compiler,
      [76,102] - the PAZ version of the compiler, and
      [76,103] - utility and sample programs.
 
 
The following is a brief outline  of  the  files  and  their
contents.
 
 
[76,100] Documentation
======================
 
README.TXT      This document

USER.FMT        User manual (Software Tools formatter format)

USER.TXT        User manual (Printable text)

PASERR.HLP      Help text for compilation error codes

PASRUN.HLP      Help text for runtime error codes
 
 
 
[76,100] Runtime Library
========================
 
PASLIB.OLB    Pascal  runtime routines. As distributed, this
              is for PDP-11 processors with no EIS,  FIS  or
              FPP running RSX. To upgrade it to your system,
              apply appropriate library replacement.
 
              LBR PASLIB/RP = PASEIS  for EIS
              LBR PASLIB/RP = PASFIS  for FIS
              LBR PASLIB/RP = PASFPP  for FPP
              LBR PASLIB/RP = PASIAS  for IAS
 
PASEIS.OBJ    Concatenated object modules to do EIS multiply
              and divide. These are:
 
 
 
29-NOV-79                  - 2 -                            

                                                            
 
 
              Module MULI  from  P11EISMPI.MAC
                     DIVI  from  P11EISDVI.MAC
 
PASFIS.OBJ    Contains  object module for FIS real aritmetic
              operations. This is module P11RAR from  source
              P11FIS.MAC.
 
PASFPP.OBJ    Concatenated   object  modules  for  FPP  real
              arithmetic operations. These are:
 
              Module P11INI from source P11FPPINI.MAC,
                     P11RAR from source P11FPP.MAC,
                     FORTR  from source P11FORFPP.MAC.
 
PASIAS.OBJ    Contains  object  module  that   has   special
              difference  for  tasks run under IAS operating
              system. This  is  module  RUNCHK  from  source
              P11IASRNC.MAC.
 
PASNOX.OBJ    Concatenated   object   modules  that  can  be
              applied to a PASLIB.OLB that has been upgraded
              from the distributed PASLIB.OLB to restore  it
              to a state that is useable on a processor with
              no  extra  hardware. It contains the following
              modules:
 
              MULI from source P11MPI.MAC
              DIVI             P11DVI.MAC
              P11RAR           P11REAL.MAC
              P11INI           P11INIT.MAC
              RUNCHK           P11RUNCHK.MAC
              FORTR            P11FORTR.MAC
 
PASLIB.PAC    Packed source  modules  for  runtime  library.
              (Use   P11DEF.MAC   module   as   prefix   for
              assembling all MAC modules in this package.)
 
 
 
[76,101] Compiler  (PAS)
========================
 
P11PAS.PAS    Pascal source of general part of compiler.
 
P11FIL.PAS    PDP-11-specific part of compiler.
 
P11CRS.PAS    DEC-10-specific part of compiler.
 
 
 
29-NOV-79                  - 3 -                            

                                                            
 
 
SPECAL.PAC    Packed source  for  special  runtime  routines
              required by the compiler itself.
 
PAS.BLD
PAS.ODL       TKB files to build compiler
 
PAS.OLB       Library  of  object modules of compiler. These
              are  the  objects  obtained   from   compiling
              P11PAS.PAS,  P11FIL.PAS and all the modules in
              SPECAL.PAC.
 
PAS.TSK       Task image of compiler. This version is to run
              under RSX-11M in  32K  on  processor  with  no
              extra hardware (ie. no EIS, FIS or FPP).
 
TRICK, ACOMPI, ADEC1, ADEC2
AINI2, AFCS (.MAC and .OBJ)
              These  routines  are  used  to accomplish some
              convoluted overlaying  which  is  required  to
              reduce  the  task size to give reasonable com-
              piler capacity.
 
 
 
[76,102] Big Compiler  (PAZ)
============================
 
This version of the compiler is esentially the same  as  the
PAS  task.  It is built with considerably heavier overlaying
and as a result uses memory resident  overlays  to  maintain
good speed performance. It needs about 67K words to run.
 
The  main  application  of  this  compiler is to compile the
compiler itself since the PAS compiler does'nt  have  enough
capacity  to  compile P11PAS.PAS. PAZ can compile P11PAS.PAS
(about 8300 lines) in about 13 minutes (PDP-11/40 - RK06).
 
PAZ.BLD
PAZ.ODL       TKB files to build PAZ
 
PAZ.TSK       PAZ compiler task  to  run  under  RSX-11M  on
              processors with no extra hardware.
 
OVTRIK.PAC    Packed source for routines that are needed for
              doing extra overlaying.
 
 
 
 
 
29-NOV-79                  - 4 -                            

                                                            
 
 
ABOD1, ABOD2, ACALLN, ACALLS, ACOMPI, ADEC1, ADEC2,
ADEC3, AEXPR, ASTMN1, ASTMN2, ASTMN3, HEAP, TRICK   (.OBJ)
 
              These are the objects of routines in OVTRIK.PAC
 
 
 
[76,103] Pascal Utilities
=========================
 
UNPACK        Asks  for the name of a packed file and splits
              it into its constituent files.
 
LISTPACK      Lists the names of files in a packed file.
 
PACK          Packs arbitrary source files into a new packed
              file. When it asks for name  of  source  file,
              you can also enter "@file" where "file" itself
              contains the names of files to be packed.
 
SELECT        Can  extract  a  particular file from a packed
              file.
 
CROSS         Program for formatting and crossreferencing  a
              Pascal program. Eg.:
 
              >RUN CROSS
              FILE: <filename><cr>  device and directory not
                      allowed, .PAS default type.  Gives new
                      source and cross reference listing in
                      <filename>.CRL.
 
PASREF        Another Pascal crossreferencer.
 
FLIST         Lists  a  source  file  on  terminal with line
              numbers.
 
 
Task images  (for  RSX-11M  v3)  for  some  of  these  these
utilities are provided. (No optional hardware required.)
 
 
 
 
 
 
 
 
 
 
29-NOV-79                  - 5 -                            

                                                            
 
 
3.  Installing Pascal
=====================
 
 
Use  FLX  to  read the files from tape to disk. The files do
not have to go into directories with the same UICs  as  used
on  the  tape,  but  they  should  not  be combined into one
directory. Each directory of files on  tape  must  be  in  a
separate  directory on disk. The remainder of the discussion
will  assume  that  the  files  are  on  disk  in  the  same
directories they were in on tape (use FLX /UI switch).
 
 
 
3.1  Preparing PASLIB
=====================
 
In  uic  [76,100] apply the appropriate library replacements
to PASLIB.OLB.
 
    LBR PASLIB/RP = PASEIS if processor has EIS
    LBR PASLIB/RP = PASFIS if processor has FIS
    LBR PASLIB/RP = PASFPP if processor has FPP
    LBR PASLIB/RP = PASIAS if operating system is IAS
 
Note that on many  PDP-11  models  (eg.  34,45,55)  the  EIS
(Extended  Instruction  Set) is built into the processor and
is not refered to as an option. Treat  these  models  as  if
they have EIS.
 
The  EIS  and  FPP replacements should be done if Fortran IV
Plus (F4P) routines will be called from Pascal.
 
After these replacements, the Pascal runtime library will be
ready as a separate OLB file.
 
If you want to  install  PASLIB  into  the  system  library,
SYSLIB, then do a library extraction and insertion.
 
    Eg. >LBR PASLIB = PASLIB/EX  ! Creates PASLIB.OBJ
        >SET /UIC=[1,1]
        >PIP /NV = SYSLIB.OLB  ! Keep copy of old SYSLIB
        >LBR SYSLIB = [76,100]PASLIB  ! Insert PASLIB routines
 
 
 
 
 
 
 
29-NOV-79                  - 6 -                            

                                                            
 
 
3.2  Preparing PAS compiler
===========================
 
The  distributed compiler task image in [76,101] is built to
run under RSX-11 with no requirement for  optional  hardware
and  only  has  to be INStalled to run on any RSX system. If
you want  an  upgraded  compiler  that  takes  advantage  of
arithmetic  hardware then there are two levels to which this
can  be  done:  re-building   only   or   re-compiling   and
re-building. (IAS users will have to at least re-build).
 
Re-building  the compiler with the upgraded PASLIB will mean
that the software-only arithmetic routines will be  replaced
by routines that use your hardware instead.
 
Re-compiling  the  compiler  Pascal  source will result in a
task that is even more closely matched to the hardware.  For
example,  if  your  processor  has EIS then the compiler, if
compiled accordingly, will  have  MUL  instructions  in-line
rather than calling the MULI routine.
 
To re-compile the compiler source:
 
    - intall  the  PAZ  compiler from [76,102] (it will only
      run on mapped systems with a  partition  of  at  least
      67K)
    - in uic [76,101] compile the two source modules:
 
          >PAZ P11PAS{switches} = P11PAS
          >PAZ P11FIL{switches} = P11FIL
 
          where switches ::=
                  /E      for processors with EIS
                  /E/G    for processors with EIS/FIS
                  /E/F    for processors with EIS/FPP
 
    - replace the object in PAS.OLB:
 
          >LBR  PAS/RP = P11PAS, P11FIL
          >;
          >;      Compress and purge to recover space
          >LBR  PAS/CO = PAS
          >PIP  PAS.OLB/PU
 
 
To build the PAS compiler:
 
    - edit  the PAS.BLD file to set the new default switches
 
 
29-NOV-79                  - 7 -                            

                                                            
 
 
      for the compiler (see comments in PAS.BLD) and to  set
      the /FP switch if FPP is being used.
 
    - if  the  compiler source was recompiled with /E switch
      as shown above then edit the PAS.ODL  file  to  remove
      the  MULI  routine  from  the  root  (see  comments in
      PAS.ODL).
 
    - arrange access to PASLIB.OLB in [76,100]:
 
          >PIP /EN = [76,100]PASLIB.OLB
 
    - invoke  the  task  builder  (eg.  >TKB  @PAS.BLD)  and
      disregard the multiply define diagnostic messages from
      TKB.
 
    - install the compiler and try it out.
 
If  the  resulting  task  image is larger than 32K words, it
will not install without using the /INC switch to change the
task extention. In this  case,  the  EXTTSK  option  in  the
PAS.BLD  file  should  be  adjusted  to result in a 32K task
image. Remember that the compiler's  workspace  is  greatest
when the task image is exactly 32K.
 
 
 
3.3  Preparing PAZ compiler
===========================
 
The  considerations  for  arithmetic  hardware  for  the PAS
compiler apply equally  to  the  PAZ  compiler.  It  can  be
re-built  from  your  new  PASLIB.OLB  (and  PAS.OLB  if you
re-compiled) as follows:
 
    - set uic to [76,102]
 
    - edit the PAZ.BLD file to set the new default  switches
      for  the compiler (see comments in PAZ.BLD) and to set
      the /FP switch if FPP is being used.
 
    - if the compiler source was  re-compiled  with  the  /E
      switch  as  shown  above then edit the PAZ.ODL file to
      remove the MULI routine from the root (see comments in
      PAZ.ODL).
 
    - arrange access to PASLIB.OLB and PAS.OLB:
 
 
 
29-NOV-79                  - 8 -                            

                                                            
 
 
          >PIP /EN = [76,100]PASLIB.OLB, [76,101]PAS.OLB
 
    - invoke  the  task  builder  (eg.  >TKB  @PAZ.BLD)  and
      disregard the multiply define diagnostic messages from
      TKB.
 
    - install PAZ and try it out.
 
The  EXTSCT option statement in PAZ.BLD controls the size of
the  compiler's  workspace.  For  maximum  workspace,   this
extention should be adjusted to make the root segment 160000
octal bytes long.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
29-NOV-79                  - 9 -                            

                                                            
 
 
4.  The Heap and what to do with it
===================================
 
Pascal  programs  (tasks)  contain a heap section which is a
contiguous area of memory that is used for dynamic variables
(heap)  at  the  low  end  and  for  static  variables   and
parameters  (stack)  at the high end. The compiler creates a
heap section in the  object  code  of  every  main  program.
(Seperatly  compiled  procedures  do not get a heap of their
own.) The size of this section is enough to  accomodate  the
static  variables  (not  considering recursion) plus a fixed
amount. If this "default" heap is not big  enough  for  your
program  then  you  can extend it at task build time or when
installing.
 
The heap psect is called 999999. This name causes  the  task
builder  to, in general, place the section at the end of the
task image. This position is essential  because  the  Pascal
runtime  initialization  assumes  that the space that can be
used for heap extends from the begining of the heap  section
to the end of the task partition.
 
At  build  time  the  heap can be extended with a TKB option
statement such as EXTSCT=999999:n, where n is the number  of
bytes of extention (octal) or EXTTSK=m where m is the number
of words of extention (decimal).
 
At install or run time, the heap can be effectively extended
by  extending  the task size with the /INC=n switch, where n
is the number of words of extention.
 
For tasks  using  overlays,  a  special  procedure  must  be
followed to position the heap section at the end of the task
image.  If memory resident overlays are being used, the heap
section must be placed at the end  of  the  virtual  address
block  accessed  by the first mapping window. In both cases,
the heap section generated by the  compiler,  must  be  made
available  as  a  separate  object  module so that it can be
positioned in the overlay structure. The way this is done is
to select module splitting when compiling the  main  program
at  a  point  just  before the final end statement. So, just
before the last end, code {$y+}. The generated  object  file
will  then contain a separate module for psect 999999 called
$HEAP. The whole object file  must  then  be  placed  in  an
object library so that this module can be explicitly refered
to in the overlay description (ODL).
 
With   a  separatly  accessible  heap  module,  the  overlay
 
 
29-NOV-79                 - 10 -                            

                                                            
 
 
description can be written to position it at the end of  the
task.  This  is  done  by creating a separate co-tree of one
segment.
 
  eg.       .ROOT  SOMLIB/LB:MAIN-*(OV1,OV2,OV3),HEAP
 
      HEAP: .FCTR  SOMLIB/LB:$HEAP
 
 
When memory resident overlays are used, there  is  a  severe
problem  introduced  that makes it difficult to position the
heap  section.  This  is  caused  by  the   task   builder's
segregation  of  read-only  and  read-write  psects  and the
introduction of two read-only psects as part of the  overlay
management  software. One way of surmounting this problem is
to use a hand coded  heap  module  which  is  given  the  RO
attribute  so  that the task builder will place it after the
other  RO  psects.  You  will  find   such   a   module   in
[76,102]OVTRIK.PAC   and   its   object   is   available  in
[76,102]HEAP.OBJ. For more  details,  see  the  comments  in
HEAP.MAC in OVTRIK.PAC.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
29-NOV-79                 - 11 -                            

                                                            
 
 
5.  Bugs
========
 
This  Pascal performs comparisons on all structured types as
a word compare loop. Since, for odd length  character  array
variables,  the last byte is undefined, comparisons of these
will, in general, be unpredictable. The correction  of  this
problem is quite involved and has not yet been attempted. To
avoid  any  problems,  never  declare  odd  length character
arrays.
 
There are certain unusual circumstances of bad  source  code
syntax  that  will  cause the compiler to hang in an endless
loop. If you suspect the compiler  is  hung,  abort  it  and
restart  the  compilation  specifying  your  terminal as the
listing device. The listing  will  stop  at  the  line  just
before the line with the bad syntax.
 
There  is  a  problem  in  calling  Fortran subroutines that
themselves do Fortran I/O.  Some  F4P  users  have  reported
success  in  circumventing  this  problem  by  removing  one
instruction from PASLIB routine FORTR. The source  for  this
routine   is   in   PASLIB.PAC,  module  P11FORFPP.MAC.  The
instruction to be removed is:

        MOV DAPADDR(GP),$OTSV

To incorporate the change in PASLIB:

        MAC P11FORFPP = P11DEF, P11FORFPP
        LBR PASLIB/RP = P11FORFPP

This fix apparantly does not work for  Fortran  IV  (Version
01C at least).
 
 
 
6.  Incomplete implementation
=============================
 
The  beginings  of  a symbolic debug facility are evident in
this compiler. It may be complete in a future release.
 
 
 
 
 
 
 
 
29-NOV-79                 - 12 -                            

                                                            
 
 
7.  Crosscompiler on DEC-10
===========================
 
To generate  a  cross  compiler  on  a  DEC-10,  proceed  as
follows:
 
  - transfer the files P11PAS.PAS and P11CRS.PAS to DEC-10,
  - compile them with the PASREL compiler from Hamburg,
  - load the produced modules and save the core image:
 
            .LOAD P11PAS,P11CRS
            .SAVE P11PAS 64
       (64 is enough but maybe less will suffice.)
 
When  run,  the  compiler  will  ask for the filename of the
source. A full name including volume and  p,pn  is  allowed.
Filename  extention  is not necessary if it is .PAS. Two new
files are produced: a list file with extension .LST  and  an
object file with extention .OBJ.
 
  Example:
        .RUN P11PAS
        *PROG
 
  will produce the files PROG.LST and PROG.OBJ
  from PROG.PAS .
 
The object file contains one PDP-11 byte per DEC-10 word and
is in PDP-11 DOS format. It can be transfered to a PDP-11 on
DECtape or other suitable medium.
 
  Example:
        .MOUNT DTA:DT/V:DTNAME/WE
        .R FILEX
        *DT:/V/Q/I=PROG.OBJ
        *^C
 
This  object  module  can then be retrieved on a PDP-11 with
RSX-11M by:
 
        >FLX SY:/RS=DT:*.*/DO/FB
 
 
 
 
 
 
 
 
 
29-NOV-79                 - 13 -                            
