diff --git a/src/id/dos33.a b/src/id/dos33.a
index 174022b..cd3a08a 100755
--- a/src/id/dos33.a
+++ b/src/id/dos33.a
@@ -12,82 +12,99 @@
 ;-------------------------------
 !zone {
 IDDOS33
-         lda   $08FE      ; $08FE must be either $36 or $B6
-         cmp   #$36       ; (prevents matching on some
-         beq   .match0    ; Infocom disks that would
-         cmp   #$B6       ; otherwise match but then load
-         beq   .match0    ; boot1 over program space and crash)
-         jmp   .notd33boot0
-
-.match0
-         lda   #$00       ; match first $1C bytes of T00S00
-         ldx   #$00       ; against standard DOS 3.3 boot0
-         ldy   #$1C
-         jsr   compare
-         !byte $01,$A5,$27,$C9,$09,$D0,$18,$A5
-         !byte $2B,$4A,$4A,$4A,$4A,$09,$C0,$85
-         !byte $3F,$A9,$5C,$85,$3E,$18,$AD,$FE
-         !byte $08,$6D,$FF,$08
-         bcc   .maybe_d33_1
-         jmp   .notd33boot0
-
-.maybe_d33_1
-         lda   #$00       ; match more bytes of T00S00
-         ldx   #$1F       ; against standard DOS 3.3 boot0
-         ldy   #$2B
-         jsr   compare
-         !byte $AE
-         !byte $FF,$08,$30,$15,$BD,$4D,$08,$85
-         !byte $3D,$CE,$FF,$08,$AD,$FE,$08,$85
-         !byte $27,$CE,$FE,$08,$A6,$2B,$6C,$3E
-         !byte $00,$EE,$FE,$08,$EE,$FE,$08,$20
-         !byte $89,$FE,$20,$93,$FE,$20,$2F,$FB
+;
+; $08FE must be either $36 or $B6 (prevents matching on some
+; Infocom disks that would otherwise match but then load
+; boot1 over program space and crash)
+;
+         lda   $08FE
+         cmp   #$36
+         beq   +
+         cmp   #$B6
+         beq   +
+         sec
+         rts
+;
+; Code at $0801 must be standard (with one exception)
+;
++        lda   #$00
+         ldx   #$00
+         ldy   #$4A
+         jsr   compare    ; if T00,S00,$00 ==
+         !byte $01
+         !byte $A5,$27
+         !byte $C9,$09
+         !byte $D0,$18
+         !byte $A5,$2B
+         !byte $4A
+         !byte $4A
+         !byte $4A
+         !byte $4A
+         !byte $09,$C0
+         !byte $85,$3F
+         !byte $A9,$5C
+         !byte $85,$3E
+         !byte $18
+         !byte $AD,$FE,$08
+         !byte $6D,$FF,$08
+         !byte WILDCARD   ; will check these later
+         !byte WILDCARD
+         !byte WILDCARD
+         !byte $AE,$FF,$08
+         !byte $30,$15
+         !byte $BD,$4D,$08
+         !byte $85,$3D
+         !byte $CE,$FF,$08
+         !byte $AD,$FE,$08
+         !byte $85,$27
+         !byte $CE,$FE,$08
          !byte $A6,$2B
-         bcc   .maybe_d33_2
-         jmp   .notd33boot0
-
-.maybe_d33_2
-         lda   #$00       ; check sector order map
+         !byte $6C,$3E,$00
+         !byte $EE,$FE,$08
+         !byte $EE,$FE,$08
+         !byte $20,$89,$FE
+         !byte $20,$93,$FE
+         !byte $20,$2F,$FB
+         !byte $A6,$2B
+         bcs   .exit
+;
+; Sector order map must be standard (no exceptions)
+;
+         lda   #$00
          ldx   #$4D
          ldy   #$10
-         jsr   compare
+         jsr   compare    ; if T00,S00,$4D ==
          !byte $00,$0D,$0B,$09,$07,$05,$03,$01
          !byte $0E,$0C,$0A,$08,$06,$04,$02,$0F
-         bcc   .maybe_d33_3
-         jmp   .notd33boot0
-
-.maybe_d33_3
-         lda   #$00       ; match 3 final bytes of T00S00
-         ldx   #$1C       ; against standard DOS 3.3 boot0
+         bcs   .exit
+;
+; Minor variant (e.g. Terrapin Logo 3.0) jumps to $08F0 and back
+; but is still safe to trace. Check for this jump and match
+; the code at $08F0 exactly.
+;
+         lda   #$00
+         ldx   #$1C
          ldy   #$03
-         jsr   compare
+         jsr   compare    ; if T00,S00,$1C ==
          !byte $8D,$FE,$08
-         bcs   .maybe_d33_4
-         jmp   .founddos33
+         bcc   .exit      ; standard code at $081C -> success
 
-.maybe_d33_4
-         lda   #$00       ; minor variation (e.g. Terrapin
-         ldx   #$1C       ; Logo 3.0) jumps to $08F0 and
-         ldy   #$03       ; back, but still safe to trace
-         jsr   compare
-         !byte $4C,$F0,$08
-         bcc   .maybe_d33_5
-         jmp   .notd33boot0
+         lda   #$00
+         ldx   #$1C
+         ldy   #$03
+         jsr   compare    ; if T00,S00,$1C ==
+         !byte $4C,$F0,$08; JMP $08F0
+         bcs   .exit      ; unknown code at $081C -> failure
 
-.maybe_d33_5
          lda   #$00
          ldx   #$F0
          ldy   #$09
-         jsr   compare
-         !byte $8D,$FE,$08,$EE,$F3,$03,$4C,$1F
-         !byte $08
-         bcs   .notd33boot0
+         jsr   compare    ; if T00,S00,$F0 ==
+         !byte $8D,$FE,$08
+         !byte $EE,$F3,$03
+         !byte $4C,$1F,$08
+;        bcs   .exit      ; unknown code at $08F0 -> failure
 
-.founddos33
-         clc
-         !byte $24        ; hide next SEC
-
-.notd33boot0
-         sec
+.exit
          rts
 }
diff --git a/src/id/inspect0.a b/src/id/inspect0.a
index 325d536..5553126 100755
--- a/src/id/inspect0.a
+++ b/src/id/inspect0.a
@@ -33,8 +33,7 @@ IDBootloader
          bcc   ++
          cmp   #$05
          beq   ++
-+
--        jmp   UseUniversal
++        jmp   UseUniversal
 
 ++
 ;
@@ -46,31 +45,6 @@ IDBootloader
          ldy   #$01
          jsr   CopyMemory
 
-         lda   #$00
-         ldx   #$00
-         ldy   #$4A
-         jsr   compare    ; if T00,S00,$00 ==
-
-; This needs to be pretty strict because, if it matches,
-; we're going to patch the sector and trace it to capture
-; the RWTS.
-
-         !byte $01,$A5,$27,$C9,$09,$D0,$18,$A5
-         !byte $2B,$4A,$4A,$4A,$4A,$09,$C0,$85
-         !byte $3F,$A9,$5C,$85,$3E,$18,$AD,$FE
-         !byte $08,$6D,$FF,$08,$8D,$FE,$08,$AE
-         !byte $FF,$08,$30,$15,$BD,$4D,$08,$85
-         !byte $3D,$CE,$FF,$08,$AD,$FE,$08,$85
-         !byte $27,$CE,$FE,$08,$A6,$2B,$6C,$3E
-         !byte $00,$EE,$FE,$08,$EE,$FE,$08,$20
-         !byte $89,$FE,$20,$93,$FE,$20,$2F,$FB
-         !byte $A6,$2B
-         ldx   #TRUE
-         bcc   .boot0
-         ldx   #FALSE
-.boot0
-         stx   gIsBoot0
-
          lda   #$00
          ldx   #$00
          ldy   #$05
@@ -99,7 +73,7 @@ IDBootloader
 ; The wildcard in 7th position catches alternate jump
 ; addresses (e.g. Wizardry I, Sundog Frozen Legacy)
 
-         !byte $01,$E0,$60,$F0,$03,$4C,$97,$08
+         !byte $01,$E0,$60,$F0,$03,$4C,WILDCARD,$08
          ldx   #TRUE
          bcc   .pascal
          lda   #$00
@@ -122,6 +96,8 @@ IDBootloader
 ;
          jsr   IDDOS33
          bcs   .notdos33
+         lda   #TRUE
+         sta   gIsBoot0
          lda   #s_dosb0
          jsr   PrintByID
          jmp   TraceDOS33