diff --git a/c64/kernal/stop.s b/c64/kernal/stop.s
index 74b2750c..03e860a9 100644
--- a/c64/kernal/stop.s
+++ b/c64/kernal/stop.s
@@ -1,3 +1,9 @@
 ; Function defined on pp272-273 of C64 Programmers Reference Guide
 stop:
+	;; Bit 7 of BUCKYSTATUS contains the state of the STOP key
+	;; (Compute's Mapping the 64, p27)
+
+	;; Get it into the carry flag by rotating left
+	lda BUCKYSTATUS
+	rol
 	rts