diff --git a/res/GAMES.CONF b/res/GAMES.CONF
index 4d4a43887..3585e6115 100755
--- a/res/GAMES.CONF
+++ b/res/GAMES.CONF
@@ -45,6 +45,7 @@
 0000,CAPTN.GOODNIGHT=Captain Goodnight
 0000,SMURFEN=Castle Smurfenstein
 0000,WOLFEN84=Castle Wolfenstein
+1001,CAVRNS.CALLISTO=Caverns of Callisto
 1001,CEILING.ZERO
 0001,CENTIPEDE
 0001,CHAMP.LODERUN=Championship Lode Runner
diff --git a/res/TITLE.HGR/CAVRNS.CALLISTO b/res/TITLE.HGR/CAVRNS.CALLISTO
new file mode 100644
index 000000000..0570b2b20
Binary files /dev/null and b/res/TITLE.HGR/CAVRNS.CALLISTO differ
diff --git a/res/TITLE.HGR/_FileInformation.txt b/res/TITLE.HGR/_FileInformation.txt
index 92cea42b0..12f0f93f6 100644
--- a/res/TITLE.HGR/_FileInformation.txt
+++ b/res/TITLE.HGR/_FileInformation.txt
@@ -40,6 +40,7 @@ BUZZARD.BAIT=Type(06),AuxType(4000),Access(C3)
 CANNONBALL.BLTZ=Type(06),AuxType(4000),Access(C3)
 CANYON.CLIMBER=Type(06),AuxType(4000),Access(C3)
 CAPTN.GOODNIGHT=Type(06),AuxType(4000),Access(C3)
+CAVRNS.CALLISTO=Type(06),AuxType(4000),Access(C3)
 CEILING.ZERO=Type(06),AuxType(4000),Access(C3)
 CENTIPEDE=Type(06),AuxType(4000),Access(C3)
 CHAMP.LODERUN=Type(06),AuxType(4000),Access(C3)
diff --git a/res/dsk/caverns of calllisto PRODOS (san inc crack).po b/res/dsk/caverns of calllisto PRODOS (san inc crack).po
new file mode 100644
index 000000000..575d6ab11
Binary files /dev/null and b/res/dsk/caverns of calllisto PRODOS (san inc crack).po differ
diff --git a/res/history.md b/res/history.md
index 24647675a..05b0e1b4e 100644
--- a/res/history.md
+++ b/res/history.md
@@ -8,6 +8,7 @@
  - Bejeweled
  - California Games
  - Castle Smurfenstein
+ - Caverns of Callisto
  - Columns
  - Congo Bongo
  - Crystal Castles
diff --git a/res/notes/wishlist.txt b/res/notes/wishlist.txt
index c07ed2618..e16913f68 100644
--- a/res/notes/wishlist.txt
+++ b/res/notes/wishlist.txt
@@ -66,7 +66,6 @@ Beach-Head
 Beach-Head II
 Boa
 Borg
-Caverns of Callisto [priority]
 Copts and Robbers
 The Dam Busters
 Fight Night
diff --git a/src/prelaunch/cavrns.callisto.a b/src/prelaunch/cavrns.callisto.a
new file mode 100644
index 000000000..6cc5974f3
--- /dev/null
+++ b/src/prelaunch/cavrns.callisto.a
@@ -0,0 +1,33 @@
+;license:MIT
+;(c) 2020 by qkumba
+
+!cpu 6502
+!to "build/PRELAUNCH/CAVRNS.CALLISTO",plain
+*=$106
+
+    !source "src/prelaunch/common.a"
+
+         +ENABLE_ACCEL
+         lda   #>callback
+         sta   $8D9
+         lda   #<callback
+         sta   $8D8
+         jmp   $800       ; decompress
+
+callback
+         +GET_MACHINE_STATUS
+         and   #CHEATS_ENABLED
+         beq   +
+         lda   $BFC
+         cmp   #$C6
+         bne   +
+         lda   #$A5
+         sta   $BFC       ; patch - don't decrease lives
++
+         jsr   $BD82
+         +DISABLE_ACCEL
+         rts
+
+!if * > $1C0 {
+  !error "code is too large, ends at ", *
+}