diff --git a/libsrc/c64/acc_detect_turbomaster.s b/libsrc/c64/acc_detect_turbomaster.s
index 0af9c3af7..2f8fb2294 100755
--- a/libsrc/c64/acc_detect_turbomaster.s
+++ b/libsrc/c64/acc_detect_turbomaster.s
@@ -37,11 +37,9 @@ _detect_turbomaster:
 ; Check for turbo master basic replacement
         ldy     TURBOMASTER_DETECT
         cpy     #$A2
-        bne     not_found
-found:
-        lda     #$01
-        .byte   $24
+        beq     found
 not_found:
         txa
+found:
         rts
 
diff --git a/libsrc/c64/acc_turbomaster_speed.s b/libsrc/c64/acc_turbomaster_speed.s
index 679003b03..7ef6b0540 100755
--- a/libsrc/c64/acc_turbomaster_speed.s
+++ b/libsrc/c64/acc_turbomaster_speed.s
@@ -38,18 +38,11 @@
 _set_turbomaster_speed:
         tay
         lda     TURBOMASTER_SPEED_REG
+        asl
         cpy     #SPEED_4X
-        bcs     high_speed
-low_speed:
-        and     #$7F
+        ror
 store_speed:
         sta     TURBOMASTER_SPEED_REG
-        jmp     _get_turbomaster_speed
-
-high_speed:
-        ora     #$80
-        bne     store_speed
-
 
 _get_turbomaster_speed:
         ldx     #$00