From: muta...@gmail.com   
      
   On Friday, November 11, 2022 at 9:33:08 AM UTC+8, Joe Monk wrote:   
   > > Yes, even on z/Arch. The only way a 32-bit program can turn into    
   > > a 64-bit program (ie, by definition, actually populating 64 bits with    
   > > meaningful values, not 0), is via recompilation.    
   > >   
   > You're referring to what is known as an effective address. Thats a different   
   address than an actual memory address. Effective addresses are translated by   
   the system to real addresses. Hence, an attribute of an effective address is   
   that it is a    
   generated address by the system.   
   > "whenever the machine generates and provides to the program a 24-bit or   
   31-bit address, the address is made available (placed in storage or loaded   
   into a general register) by being imbedded in a 32-bit field, with the   
   leftmost eight bits or one bit in    
   the field, respectively, set to zeros."    
      
   And some niche mainframe operating systems return the full   
   32 bits. If you have a 32-bit executable, as all of mine are, they   
   have access to a full 4 GB of memory under the right circumstances.   
      
   And also note that the OS normally just returns an address of the   
   start of a memory block. The application, using 32-bit instructions,   
   then creates 32-bit addresses of its own, that the OS has no explicit   
   knowledge of (but may suddenly find out when one is passed to it).   
      
   BFN. Paul.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)