Add int to float conversions

src/basic/math/sign_extend_A_to_Y.s

@@ -0,0 +1,13 @@
+;; #LAYOUT# STD *       #TAKE
+;; #LAYOUT# *   BASIC_0 #TAKE
+;; #LAYOUT# *   *       #IGNORE
+
+;
+; Math package - helper function to sign extend accumulator into Y
+
+sign_extend_A_to_Y:
+    cmp #$80                ; Copy sign into carry
+    ldy #$00                ; Y = $00
+    bcc @1                  ; Branch if not negative
+    dey                     ; Y = $FF
+@1: rts