    code.</td>
  </tr>
  <tr valign="top"> 
    <td><strong>SP</strong></td>
    <td>The stack pointer register. In the RAM displays, the stack pointer is 
      highlighted blue with yellow text.</td>
  </tr>
  <tr valign="top"> 
    <td><strong>SR</strong></td>
    <td>The status register. This contains flags that are set as a result of the 
      most recent calculation. A zero result will set the Z (zero) flag. A negative 
      result will set the S (sign) flag. A result too big to fit in a 