From: muta...@gmail.com   
      
   On Sunday, September 4, 2022 at 9:25:34 PM UTC+8, wolfgang kern wrote:   
   > On 04/09/2022 06:32, muta...@gmail.com wrote:   
   > ...   
   > > Although we can't change existing hardware, we can   
   > > start by agreeing that Intel engineers missed   
   > > some things that only came to light when   
   > > pointed out by an obnoxious Australian, instead of   
   > > dismissing everything he says in favor of   
   > > professional infallible Americans.   
   > in terms of costs and performance it was an absolute correct   
   > solution at the time back then. [COP4..8080,8085,8086]   
   > Improvements came with time anyway, we cannot alter history.   
   > > After establishing that apparent truth we can   
   > > discuss what options exist to compensate for American engineering failures.   
   >   
   > > This includes the option of altering or   
   > > replacing historical software.   
   > you can only replace it. no way to modify old CPUs.   
   > > Here's the PSP thing:   
   > >   
   > > https://groups.google.com/g/comp.os.msdos.programmer/c/ZvWGK   
   T5Fvc/m/skFPO1H3EAAJ   
   > [quote]   
   > > So:   
   > >   
   > > 05h = 9A   
   > > 06/07 = FEF0   
   > > 08h = 1D   
   > > 09h = F0   
   > >   
   > > So the 06/07 "segment size" of nearly 64k is basically   
   > > just maxing out the memory available to the .com   
   > > program.   
   > >   
   > > But how does 9A + 1D + F0 translate into a call to 00C0?   
   >   
   > you have this all wrong :):)   
   > 9A F0 FE 1D F0 is an absolute CALL FAR into a BIOS location   
   > FEFO become IP and F01D became CS (could be a branch to 00C0)   
   > __   
   > wolfgang   
      
   It was not absolutely correct, it was almost   
   correct. They just needed to document some things   
   to future proof it or add some minimal   
   enhancements.   
      
   You can argue that the things I have   
   identified weren't known to computer   
   science at the time and we're only   
   added to science in 2022 so it is not   
   their fault.   
      
   Noone had done segmentation before and it   
   would take decades of science still to   
   work through the repercussions.   
      
   And yes, we can't change the physical   
   processor nor history, but we can make   
   use of 40 years of additional science to   
   see what could have been done differently.   
   slight changes, not complete replacement.   
      
   Alternatively we can stick out fingers in   
   our ears and deny that it is possible for   
   someone from the southern hemisphere to   
   improve the design of a group of northern   
   hemispherans.   
      
   Which do you prefer?   
      
   And you CAN change historical software,   
   either by zapping the binary or   
   recompiling the source code.   
      
   The source code to msdos 2.0   
   has been made available.   
      
   Microsoft likely still has all the other source   
   available too.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)