diff --git a/src/prelaunch/one.on.one.a b/src/prelaunch/one.on.one.a
new file mode 100644
index 000000000..9668e23ec
--- /dev/null
+++ b/src/prelaunch/one.on.one.a
@@ -0,0 +1,42 @@
+;license:MIT
+;(c) 2020 by qkumba
+
+!cpu 6502
+!to "build/PRELAUNCH/ONE.ON.ONE",plain
+*=$106
+
+    !source "src/prelaunch/common.a"
+
+         +READ_RAM2_NO_WRITE
+         jsr   EnableAccelerator
+         lda   MockingboardStuff
+         cmp   #1
+         ora   #$C0
+         +READ_ROM_NO_WRITE
+         php
+         pha
+         lda   #$60
+         sta   $408B
+         jsr   $4000      ; decompress
+         pla
+         plp
+         bcc   skipmb
+         cmp   #$C4
+         beq   skipmb
+
+         sta   $E9BC      ; Replace #$C4 with configured slot
+         ldy   #00
+-        ldx   $EAF6,Y    ; Find #$C4s
+         cpx   #$C4
+         bne   +
+         sta   $EAF6,Y    ; Replace #$C4 with configured slot
++        iny
+         bne   -
+
+skipmb
+         jsr   DisableAccelerator
+         jmp   $400
+
+!if * > $1C0 {
+  !error "code is too large, ends at ", *
+}