Add sqr_FAC2

src/basic/math_trans/bf74.sqr_FAC2.s

@@ -3,9 +3,13 @@
 ;; #LAYOUT# *   BASIC_0 #TAKE
 ;; #LAYOUT# *   *       #IGNORE
 
-;
+; This file is under the MIT license, it contains code released by Microsoft Corporation.
+; See LICENSE for more information.
+
 ; Math package - square root of FAC2
 ;
+; This is verified to be identical to the original Microsoft implementation where it was unnamed
+;
 ; Note:
 ; - loads .5 into FAC1 and falling through to the exponentiation routine
 ;
@@ -15,8 +19,17 @@
 ; - https://codebase64.org/doku.php?id=base:kernal_floating_point_mathematics
 ;
 
-; XXX provide implementation
+!ifdef CONFIG_TRANSCENDENTAL_FUNCTIONS {
+
 
 sqr_FAC2:
 
-	+STUB_IMPLEMENTATION
+        lda #<const_HALF
+        ldy #>const_HALF
+
+        ; FALLLTROUGH to pwr_FAC2_MEM
+
+
+} else {
+    jmp do_NOT_IMPLEMENTED_error
+}