From: muta...@gmail.com   
      
   On Saturday, July 17, 2021 at 12:32:15 AM UTC+10, muta...@gmail.com wrote:   
      
   > > available. I was thinking it would be useful to do the   
   > > latter if I had mixed 32-bit and 16-bit code. But if I was   
   > > doing that, I would have a different GDT, like I already   
   > > have in current PDOS/386 (ie very minimal). And flip   
   > > between the two.   
      
   > Since I can only get 512 MiB for 16-bit programs anyway,   
   > I may as well have the mandatory 6 selectors or whatever   
   > to address the first 3.5 GiB of memory for 32-bit programs   
   > and the rest of the selectors used for 16-bit programs in   
   > the other 512 MiB of memory.   
      
   I don't suppose there is a way to have, in addition to the   
   above, of having 64-bit programs run in the 4 GiB to   
   32 GiB region?   
      
   According to this:   
      
   https://en.wikipedia.org/wiki/X86-64#Operating_modes   
      
   there is 16-bit and 32-bit available to some degree, even   
   in long mode.   
      
   My requirement is for the selected subset of 8086   
   programs that follow "the rules" to work in their   
   allotted 512 MiB region. So that means the programs   
   load cs and ds constantly. If that is not available in   
   this "CM16", it's no use to me, and I'll stick to running   
   16-bit programs in PM32 for now.   
      
   BFN. Paul.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)