add cheat for Xevious

2024-06-17 23:29:31 +00:00 · 2019-10-11 10:28:30 -04:00 · 2019-10-11 10:28:30 -04:00 · 65875d9028
commit 65875d9028
parent b5fc6f4ad9
3 changed files with 38 additions and 2 deletions
--- a/res/games.conf
+++ b/res/games.conf
--- a/res/history.md
+++ b/res/history.md
@ -12,7 +12,7 @@

 - Added help screen (press ? in search or browse mode to show)
 - Added global cheat mode (press Ctrl-C in search or browse mode to toggle)
- - Added 60 game cheats
+ - Added 61 game cheats
 - Fixed corrupted graphics in Asteroid Blaster
 - Fixed corrupted graphics in Sneakers game, demo, and screenshots, and now we are entirely done with this I promise
 - Fixed Axis Assassin demo hanging on IIgs
--- a/src/prelaunch/xevious.a
+++ b/src/prelaunch/xevious.a
@ -0,0 +1,36 @@
+;license:MIT
+;(c) 2019 by 4am
+
+!cpu 6502
+!to "build/PRELAUNCH/XEVIOUS",plain
+*=$106
+
+         !source "src/prelaunch/common.a"
+
+         +ENABLE_ACCEL
+         +GET_MACHINE_STATUS
+         and   #CHEATS_ENABLED
+         sta   patch2+1
+         lda   #<patch1
+         sta   $35E4
+         lda   #>patch1
+         sta   $35E5
+         jmp   $34AA      ; decompress 1
+patch1
+         +DISABLE_ACCEL
+         lda   #<patch2
+         sta   $ACE8
+         lda   #>patch2
+         sta   $ACE9
+         jmp   $AC48      ; decompress 2
+patch2
+         lda   #0         ; SMC
+         beq   +
+                          ; lives in $602B
+         lda   #$AD
+         sta   $6414      ; patch - don't decrease lives
+         sta   $6A8C      ; patch - don't increase lives
+         sta   $750D      ; patch - don't increase lives
+         sta   $894F      ; patch - don't increase lives
+
+         jmp   $0600