🚀 go-pugleaf

/* Written  5:49 pm  Nov 25, 1986 by nacer@orstcs.cs.ORST.EDU in orstcs:net.lang.pasca */
/* ---------- "ORIGIN, ADSMEM ???" ---------- */

I am trying out MS-Pascal and I would like to know whether it is possible
to do either of this three things:

  A) declare a variable at a specific physical address (Segment & Offset).
  B) assign and physical address value (Segment & Offset) to a pointer
     variable.
  C) declare a variable X on top of an already declared (of course) variable
     Y, so that they share the exact same starting location in memory.

  I have noticed the existence of ORIGIN and ADSMEM in Microsoft-Pascal
  and I have tried to simulate the Turbo-Pascal implementation of ABODULTE
  and the function PTR but with no success.

  Below are the programs  A, B, and C which show what I am trying to achive.

  Any hints will be greatly appreciated.  Thank you.

  Reply by mail to:                   hp-pcd!orstcs!nacer
  or post.


PROGRAM  A  ( INPUT, OUTPUT ) ;
 TYPE   X_TYPE = ARRAY[ 1..10 ] OF BYTE ;
 VAR    X [ORIGIN 16#A000 : 16#0 ] : X_TYPE ;
                       { in Turbo-Pascal--> x : x_type absolute $A000:$0000 ;}
BEGIN   X[ 1 ] := 255    END .


PROGRAM  B  ( INPUT, OUTPUT ) ;
 TYPE   X_TYPE = ARRAY[ 1..10 ] OF BYTE ;
 VAR    X : ^X_TYPE ;                       {here x is a pointer to an array}
BEGIN   X := ADSMEM[ #A000 ] ;  X[1] := 255  END .
                                    {in Turbo-Pascal--> X := PTR( A000, 0 ) ;}

PROGRAM  C  ( INPUT, OUPUT ) ;
 VAR
  Y : INTEGER ;
  X : ????                       {Turbo-Pascal--> X : INTEGER ABSOLUTE Y ;}

BEGIN
 Y := 10 ;
 WRITELN( X ) ;                  {X have the value 10in this case}
END .


     Thank you!                     hp-pcd!orstcs!nacer

/* End of text from orstcs:net.lang.pasca */