title: FBSTP store wrong value
body: <p>I am writing a program that calculate arctan function.<br> Function that does all work works fine, but when i try get bcd-value fbstp command store weird value and fstp store right value.</p>
  
  <pre><code>segment data 
  result:  resb 10
  tmp_val: dd 000000000h
  precs:   dq 03a83126fh ; 0.001
  arg:     dd 03f800000h ; 0.7
  
  segment code
  ..start:
  
  mov ax,data
  mov ds, ax
  finit
  
  call calc_value
  fst dword[tmp_val]
  fbstp tword [result]
  
  mov ax, 4C00h
  int 21h
  </code></pre>
  
  <p>And after execution in memory
  at tmp_val: 0x3f490edb (0.785383)<br>
  and at result: 0x0000000000000000001</p>
  
  <p>And i write this for DOS </p>