patch 13-sector DLM disks that call BCF0 from 9D84

src/passport.a

@@ -95,7 +95,7 @@ flag     =     $FF        ; byte
 }
 
 ; Application constants (not zero addresses)
-RELBASE  =     $5800      ; address to move Passport code
+RELBASE  =     $5700      ; address to move Passport code
                           ; so that it's out of the way
 LOWPOINT =     $4300      ; lowest available address for code
 BASEPAGE =     $10        ; Special Delivery tracer assumes
@@ -710,6 +710,7 @@ _applyToT00
          !source "patchers/pascalrwts.a"
          !source "patchers/micrograms.a"
          !source "patchers/dos32.a"
+         !source "patchers/dos32dlm.a"
 _applyToAll
          !source "patchers/universale7.a"
          !source "patchers/a6bc95.a"            ; gIsPascal only

src/patchers/dos32dlm.a

@@ -0,0 +1,25 @@
+;-------------------------------
+; #DOS32DLM
+; $9D84 jumps to $BCF0 to set the input vector to trap <Ctrl-C> during boot
+; (crashes because we don't include their custom code at $BCF0 when we
+; reconstruct the bootloader)
+;
+; tested on
+; Alien Addition (1982, DLM)
+; Alligator Mix (1982, DLM)
+; Dragon Mix (1982, DLM)
+;-------------------------------
+!zone {
+         lda   gIsDOS32
+         bne   .exit
+         lda   #$0b
+         ldx   #$84
+         ldy   #$03
+         jsr   compare    ; if T00,S0B,$84 ==
+         !byte $4C,$F0,$BC
+         bcs   .exit
+         ldy   #$03
+         jsr   modify     ; then set T00,S0B,$84 =
+         !byte $AD,$E9,$B7
+.exit
+}