begin implementing basic text manipulation routines.

c64/basic/basic_insert_line.s

@@ -0,0 +1,11 @@
+	;; Insert the tokenised line stored at $0200.
+	;; First work out where in the list to put it
+	;; (basic_find_line with the line number can be used to work
+	;; out the insertion point, as it should abort once it finds a
+	;; line number too high).
+	;; Then all we have to do is push the rest of the BASIC text up,
+	;; and update the pointers in all following basic lines.
+basic_insert_line:
+	sec
+	rts
+