Name: SQRT3.ASM
         Type: Assembler Macro
      Version: 1.0
  Last Change:  9-Feb-87

  Description: Full Precision Square Root Macro

 SQRT3 calculates the square root of an input number.  The input
 may be any 48 bit positive fraction, including zero.  The input
 number is assumed to be in Y (Y1:Y0) and the resulting square
 root is returned in B.

 The algorithm uses a successive approximation technique to
 achieve full 23 bit precision in the result.  Beginning with
 the most significant bit, it sets each bit to form a best guess,
 squares the guess and compares the result to the input number. 
 If the guess is too big, that bit is reset and the next least
 significant bit is checked.

 The library program SQRT3T provides an example of how to use the
 SQRT3 macro.