add support for BBF9 desync protection check seen in late 80s / early 90s Sunburst disks

src/passport.a

@@ -713,6 +713,7 @@ _applyToAll
          !source "patchers/prodosrwts.a"        ; gIsProDOS only
          !source "patchers/prodos6a.a"          ; gIsProDOS only
          !source "patchers/prodosmecc.a"        ; gIsProDOS only
+         !source "patchers/bbf9.a"              ; gIsProDOS only
          !source "patchers/rwtsswapmecc.a"      ; gIsMECCFastloader only
          !source "patchers/protecteddos.a"      ; gIsProtDOS only
          !source "patchers/fbff.a"

src/patchers/bbf9.a

@@ -0,0 +1,40 @@
+;-------------------------------
+; #BBF9
+; patch nibble check seen in
+; Sunburst disks 1988 and later
+;
+; see write-up of 4am crack
+; no. 1165 Muppet Slate
+;
+; tested on
+; Muppet Slate (1988)
+; Memory Building Blocks (1989)
+; Odd One Out (1989)
+; Regrouping (1989)
+; Simon Says (1989)
+; Teddy and Iggy (1990)
+; 1-2-3 Sequence Me (1991)
+;-------------------------------
+!zone {
+         lda   gIsProDOS
+         bne   .exit
+         ldy   #$0E
+         jsr   SearchTrack
+         !byte $A6,WILDCARD
+         !byte $BD,$89,$C0
+         !byte $BD,$8E,$C0
+         !byte $18
+         !byte $A5,WILDCARD
+         !byte $69,$8C
+         !byte $8D
+         bcs   .exit
+         sta   gDisplayBytes
+         pha
+         lda   #s_bbf9
+         jsr   PrintByID
+         pla
+         ldy   #$02
+         jsr   modify
+         !byte $18,$60
+.exit
+}

src/strings/en.a

@@ -98,7 +98,8 @@ s_diversidos = $4F
 s_prontodos =  $50
 s_jmpb412 =    $51
 s_laureate =   $52
-STRINGCOUNT =  $53
+s_bbf9   =     $53
+STRINGCOUNT =  $54
 
 !zone {
 StringTable
@@ -185,6 +186,7 @@ StringTable
          !word .prontodos
          !word .jmpb412
          !word .laureate
+         !word .bbf9
 ;
 ; Text can contain substitution strings, which
 ; are replaced by current values at runtime. Each
@@ -210,7 +212,7 @@ StringTable
 ; can be set directly before calling PrintByID.
 ;
 .header
-         !text "Passport by 4am               2017-05-16",00
+         !text "Passport by 4am               2017-05-21",00
 .mainmenu
          !text "________________________________________",$8D,$8D,$8D,$8D,$8D,$8D,$8D
          !text "              "
@@ -466,4 +468,6 @@ StringTable
          !text "at $B412 before initializing DOS.",$8D,00
 .laureate
          !text "T00,S00 Found Laureate bootloader",$8D,00
+.bbf9
+         !text "T%t,S%0 Found BBF9 protection check",$8D,00
 }