From: redelm@nospicedham.ev1.net.invalid   
      
   R.Wieser  wrote in part:   
   > Robert,   
   >> It might have some safeguards against executing data :)   
   >   
   > I've used the "trick" before, so I don't think so.  Currently I'm   
   > torn between the posibilities that the processor I'm using might   
   > not be having that command, that I'm simply bungling up or that   
   > there is some kind of memory alignment involved (the latter one   
   > would not be the first time I've run into it).   
      
   Well, please make sure the pointer is correct (trash easily   
   gets caught in the upper bits in mixed-mode) and your pgm owns   
   the memory it points at.  Otherwise, segfault.   
      
   >> Actually, I believe the registers are a circular file,   
   > It has to be, as my example code works : after the second FLD1 the TOS is 6.   
   > But I can still execute a FSTP ST(2) ,which seemingly points at 6+2 = 8.   
      
   Ah, but circularity is achieved by masking, 8=0 when masked at 3bits.   
      
   >> 34 years ago I wrote an extention to MS-DOS DEBUG.COM   
   >> to examine the x87.   
   >   
   > I'm not sure what you mean with an 'extension' (wasn't aware that   
   > Debug supported such a thing), but years ago I wrote something for it   
   > (using memory patching) so it could deal with a few more opcodes.   
      
   Very similar.  I added code and patched the command jump table   
   to enter it when commanded.   
      
   -- Robert   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)