diff --git a/applecorn.po b/applecorn.po
index e91f389..eb0c744 100644
Binary files a/applecorn.po and b/applecorn.po differ
diff --git a/auxmem.init.s b/auxmem.init.s
index 8c031b8..c416ea1 100644
--- a/auxmem.init.s
+++ b/auxmem.init.s
@@ -290,7 +290,7 @@ BYTE00      BEQ   BYTE00A         ; OSBYTE 0,0 - generate error
             RTS                   ; %000x1xxx host type, 'A'pple
 BYTE00A     BRK
             DB    $F7
-HELLO       ASC   'Applecorn MOS 2022-12-06'
+HELLO       ASC   'Applecorn MOS 2022-12-07'
             DB    $00             ; Unify MOS messages
 * TO DO: Move into RAM
 GSSPEED     DB    $00             ; $80 if GS is fast, $00 for slow
diff --git a/mainmem.mock.s b/mainmem.mock.s
index e89a1fe..6fe16b4 100644
--- a/mainmem.mock.s
+++ b/mainmem.mock.s
@@ -194,11 +194,15 @@ MOCKAMP     PHX
 
 * Mockingboard interrupt service routine - just calls generic audio ISR
 MOCKISR     CLD
-* TODO: Check whether interrupt is from Mockingboard or not
+            LDA   MOCK_6522_IFR            ; Interrupt flag register
+            AND   #$40                     ; Bit 6
+            BEQ   :NOTMB                   ; Wasn't Mockingboard IRQ
             BIT   MOCK_6522_T1CL           ; Clear interrupt
             JSR   AUDIOISR
             CLC                            ; CC indicates we serviced irq
             RTS
+:NOTMB      SEC                            ; We did not handle irq
+            RTS
 
 
 **
diff --git a/mame_applecorn b/mame_applecorn
index a21de9b..05ac8af 100755
--- a/mame_applecorn
+++ b/mame_applecorn
@@ -1,2 +1,2 @@
-#mame -w apple2ee -debug -sl5 mouse -sl7 cffa2 -harddisk1 ~/Personal/Development/Applecorn/applecorn.po
-mame -w apple2gs -debug -sl7 cffa2 -harddisk1 ~/Personal/Development/Applecorn/applecorn.po -harddisk2 tests/JGHMusic2.po
+mame -w apple2ee -debug -sl5 mouse -sl7 cffa2 -harddisk1 ~/Personal/Development/Applecorn/applecorn.po
+#mame -w apple2gs -debug -sl7 cffa2 -harddisk1 ~/Personal/Development/Applecorn/applecorn.po -harddisk2 tests/JGHMusic2.po