From: redelm@nospicedham.ev1.net.invalid   
      
   R.Wieser  wrote in part:   
   > Robert,   
   >> Well, please make sure the pointer is correct   
   >   
   > :-) And how do you propose that should be done ?   
   > It sounds like a great idea, but ...   
      
   Walk before you run, when in trouble, drop back.  Before trying   
   a potentially troublesome instruction like FXSAVE, use MOV.   
   Even hand-assemble from hex if those facilities are in doubt:   
      
   	MOV EAX, "pointer"    ; to see if you can read loc   
   	MOV "pointer", EAX    ; to see if you can write   
      
      
   >> (trash easily gets caught in the upper bits in mixed-mode)   
   >   
   > Somewhere along the line I forgot to mention that I was programming in 32-bit   
   > mode (under Win XP).  So, no mixed mode and no trash in the upper bits.   
      
   I don't think XP does 64, but the CPU might.  The upper-upper could   
   get trash.  ISTR needing to set something to get IN/OUT to work.   
      
      
   >> Ah, but circularity is achieved by masking, 8=0 when masked at 3bits.   
   >   
   > Well ...  It /can/ be achieved that way, but only under   
   > certain conditions (related to origin and size). :-)   
      
   Zero origin, power-of-two size.  Check on both.   
   Ever wonder why there are so many buffers this way?   
      
   > The problem has been located though : I simply used the wrong R/M value   
   > while hand-encoding the FXSAVE command (likely mixing up the 16 bit table   
   > with the 32 bit one).   IOW, I was providing the target addres in a certain   
   > register while the command expected it in another register/form.   
      
   Debugging with MOV test (hand-assembled) could have caught.   
      
   -- Robert   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)