diff --git a/src/apicode.a b/src/apicode.a
index 98bac7f..0155e08 100644
--- a/src/apicode.a
+++ b/src/apicode.a
@@ -64,6 +64,10 @@
                           ; set in IDBootloader() after reading T00,S00
 
 FIRSTFILTER
+;gIsDiversi
+         !byte FALSE      ; 0=true, 1=false
+                          ; reset before each operation
+                          ; set in IDBootloader() after reading T00,S00
 ;gIsPhoenix
          !byte FALSE      ; 0=true, 1=false
                           ; reset before each operation
diff --git a/src/apidefs.a b/src/apidefs.a
index 679ef74..deee067 100644
--- a/src/apidefs.a
+++ b/src/apidefs.a
@@ -101,9 +101,10 @@ gIsRDOS13                     = gIsDavidson-$01                   ; byte
 gIsMUSERWTS                   = gIsRDOS13-$01                     ; byte
 gIsHolle                      = gIsMUSERWTS-$01                   ; byte
 gIsPhoenix                    = gIsHolle-$01                      ; byte
+gIsDiversi                    = gIsPhoenix-$01                    ; byte
 ;LASTFILTER ; add new gIs* above this line
 ;gIsInfocom18 is a special case whose ID is not in the regular inspection path
-gIsInfocom18                  = gIsPhoenix-$01                    ; byte
+gIsInfocom18                  = gIsDiversi-$01                    ; byte
 ;gIs13Sector is a special case whose ID is not in the regular inspection path
 gIs13Sector                   = gIsInfocom18-$01                  ; byte
 ;gMECCFastloadType is a special case integer whose default value cannot be #FALSE
@@ -177,6 +178,7 @@ ConstructStandardDelivery = jConstructStandardDelivery
 !warn "gIsMUSERWTS=",gIsMUSERWTS
 !warn "gIsHolle=",gIsHolle
 !warn "gIsPhoenix=",gIsPhoenix
+!warn "gIsDiversi=",gIsDiversi
 !warn "gIsRDOS13=",gIsRDOS13
 !warn "gIsInfocom18=",gIsInfocom18
 !warn "gIs13Sector=",gIs13Sector
diff --git a/src/id/diversidos.a b/src/id/diversidos.a
index 56fa6d7..5b861c5 100644
--- a/src/id/diversidos.a
+++ b/src/id/diversidos.a
@@ -17,5 +17,10 @@ IDDiversi
          ldy   #$0B
          jsr   compare    ; if T00,S00,$F1 ==
          !byte $B3,$A3,$A0,$D2,$CF,$D2,$D2,$C5,$8D,$87,$8D
+         bcs   .no
+         lda   #TRUE
+         sta   gIsDiversi
+
+.no
          rts              ; passport-test-suite/Moon Bingo.woz [C=0] matches
 }
diff --git a/src/passport.a b/src/passport.a
index d4e6ed7..2cea79c 100755
--- a/src/passport.a
+++ b/src/passport.a
@@ -802,6 +802,7 @@ _applyToAll
          !source "patchers/zoomgrafix.a"        ; gIsPhoenix only
          !source "patchers/e7everywhere.a"      ; gIsBoot0 || gIsProDOS only
          !source "patchers/choplifter.a"        ; gIsChoplifter only
+         !source "patchers/basham.a"            ; gIsDiversi only
 
          lda   gPatchCount
          beq   .nopatches
diff --git a/src/patchers/basham.a b/src/patchers/basham.a
new file mode 100644
index 0000000..3816b5a
--- /dev/null
+++ b/src/patchers/basham.a
@@ -0,0 +1,38 @@
+;-------------------------------
+; #BASHAM
+; obfuscated nibble check
+; used by Passport Systems
+;
+; tested on
+; - Korg-800 4 Track Midi Sequencer
+; - MIDI-8 Plus
+; - Polywriter
+;-------------------------------
+!zone {
+         bit   gMode       ; nothing to do here in verify-only mode
+         bpl   .exit
+         lda   gIsDiversi  ; only if we found Diversi-DOS boot sector earlier
+         bne   .exit
+         ldy   #14
+         jsr   SearchTrack
+         !byte $A0,$0F     ; LDY #$0F
+         !byte $B9,$00,$00 ; LDA $0000,Y
+         !byte $99,$E4,$95 ; STA $95E4,Y
+         !byte $88         ; DEY
+         !byte $10,$F7     ; BPL *-9
+         !byte $4C,$E3,$93 ; JMP $93E3
+         bcs   .exit
+         sta   gDisplayBytes
+         pha
+         lda   #s_basham
+         jsr   PrintByID
+         txa
+         clc
+         adc   #12
+         tax
+         pla
+         ldy   #$02
+         jsr   modify
+         !byte $99,$8E     ; jmp directly to decoder
+.exit
+}
diff --git a/src/patchers/choplifter.a b/src/patchers/choplifter.a
index 287f5b8..c30d339 100644
--- a/src/patchers/choplifter.a
+++ b/src/patchers/choplifter.a
@@ -22,7 +22,7 @@
 ; - Star Blazer (Broderbund)
 ;-------------------------------
 !zone {
-         rts              ; reachable only via inspect
+         jmp   .exit2     ; reachable only via inspect
 
 Choplifter
          lda   #$00
@@ -496,4 +496,6 @@ ReadChoplifter
          rts
     } ;$5xx
   } ;$Bxxx
+
+.exit2
 }
diff --git a/src/strings/en.a b/src/strings/en.a
index ae3dc2e..59705dd 100755
--- a/src/strings/en.a
+++ b/src/strings/en.a
@@ -134,6 +134,7 @@ StringTableLow
          !byte <.diskvol0
          !byte <.e7everywhere
          !byte <.choplifter
+         !byte <.basham
 
 StringTableHigh
          !byte >.header
@@ -254,6 +255,7 @@ StringTableHigh
          !byte >.diskvol0
          !byte >.e7everywhere
          !byte >.choplifter
+         !byte >.basham
 
 ;
 ; Text can contain substitution strings, which
@@ -280,7 +282,7 @@ StringTableHigh
 ; can be set directly before calling PrintByID.
 ;
 .header
-         !text "Passport by 4am               2019-08-28",$00
+         !text "Passport by 4am               2019-10-10",$00
 .mainmenu
          !text "________________________________________",$8D,$8D,$8D,$8D,$8D,$8D,$8D,$8D
          !text "               "
@@ -607,4 +609,6 @@ StringTableHigh
          !text "T%t,S%0 Found E7 Everywhere protection",$8D,$00
 .choplifter
          !text "Roland was here, but he left...",$8D,$00
+.basham
+         !text "T%t,S%0 Found Basham protection",$8D,$00
 }
diff --git a/src/strings/enid.a b/src/strings/enid.a
index 899f190..4abb353 100644
--- a/src/strings/enid.a
+++ b/src/strings/enid.a
@@ -120,4 +120,5 @@ s_hoffman =    $72
 s_diskvol0 =   $73
 s_e7everywhere=$74
 s_choplifter = $75
-STRINGCOUNT =  $76
+s_basham     = $76
+STRINGCOUNT =  $77