diff --git a/auxmem.misc.s b/auxmem.misc.s
index b9bbce7..ebad1ab 100644
--- a/auxmem.misc.s
+++ b/auxmem.misc.s
@@ -371,7 +371,9 @@ ROMINIT     STZ   MAXROM           ; One sideways ROM only
 :X1         CMP   #7
             BNE   :X2
             STA   MAXROM
-:X2         RTS
+:X2         LDA   #$FF
+            STA   ROMID            ; Ensure invalid initial value
+            RTS
 
 
 **********************************************************
diff --git a/mainmem.audio.s b/mainmem.audio.s
index 3a90441..5e5b674 100644
--- a/mainmem.audio.s
+++ b/mainmem.audio.s
@@ -176,9 +176,10 @@ MAININS     >>>   ENTMAIN
 
 
 * Remove value from buffer or examine buffer (API same as Acorn MOS REMV)
+* NOTE OS1.20 has a bug in the EXAMINE path
 * On entry: X is buffer number, V=1 if only examination is requested
-* On exit: If examination, A next byte, X preserved, Y=offset to next char
-*          If removal, A undef, X preserved, Y value of byte removed
+* On exit: If examination, A next byte, X preserved, Y=next byte
+*          If removal, A undef, X preserved, Y=value of byte removed
 *          If buffer already empty C=1, else C=0
 REM         PHP                              ; Save flags, turn off interrupts
             SEI
@@ -201,6 +202,7 @@ REM         PHP                              ; Save flags, turn off interrupts
             CLC                              ; Success
             RTS
 :EXAM       PLA                              ; Char read from buffer
+            TAY                              ; BUGFIX: Omitted on OS1.20
             PLP
             CLC                              ; Success
             RTS