From ef4f60166dc116845de0ef91e0e060b6b98aacfb Mon Sep 17 00:00:00 2001
From: Peter Ferrie <peter.ferrie@gmail.com>
Date: Tue, 11 Aug 2020 18:02:04 -0700
Subject: [PATCH] support Odin (#28)

---
 src/anti-m.a      |  7 +++++--
 src/idalphabeta.a | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)
 create mode 100644 src/idalphabeta.a

diff --git a/src/anti-m.a b/src/anti-m.a
index 6d721c4..a75f4d3 100644
--- a/src/anti-m.a
+++ b/src/anti-m.a
@@ -6,7 +6,7 @@
 ;-------------------------------
 ; Anti-M
 ; a 4am hack
-; (c) 2019 by 4am
+; (c) 2019-2020 by 4am
 ;
 ; Permission is hereby granted, free of charge, to any
 ; person obtaining a copy of this software and associated
@@ -187,6 +187,8 @@ Tracer
          bcc   BeginTheBoot
          jsr   IDProgame
          bcc   BeginTheBoot
+         jsr   IDAlphaBeta
+         bcc   BeginTheBoot
 ; [execution falls through here]
 ; [and runs anyway]
 
@@ -253,7 +255,7 @@ StringTable
          !word @mainmenu
 
 @header
-         !text "Anti-M v1.6 by 4am            2019-11-09"
+         !text "Anti-M v1.7 by 4am            2020-08-11"
          !text "________________________________________",$8D
          !text $8D,$8D,$8D,$8D,$8D,$8D,$8D,$8D,$00
 @mainmenu
@@ -270,3 +272,4 @@ StringTable
          !src  "src/idprodos.a"
          !src  "src/idprogame.a"
          !src  "src/idpersonal.a"
+         !src  "src/idalphabeta.a"
diff --git a/src/idalphabeta.a b/src/idalphabeta.a
new file mode 100644
index 0000000..1685cc9
--- /dev/null
+++ b/src/idalphabeta.a
@@ -0,0 +1,37 @@
+; Alpha-Beta tracer
+; written by qkumba
+;
+; tested on
+; - Odin
+;
+IDAlphaBeta
+         lda   #8
+         ldx   #1
+         ldy   #15
+         jsr   CompareMemory
+         !byte $48         ;PHA
+         !byte $28         ;PLP
+         !byte $8C,$F4,$03 ;STY $03F4
+         !byte $2C,$81,$C0 ;BIT $C081
+         !byte $2C,$81,$C0 ;BIT $C081
+         !byte $98         ;TYA
+         !byte $99,$08,$FF ;STA $FF08,Y
+         bcs   @exit
+
+; patch code to offer magic values
+         lda   #$A9        ;LDA
+         sta   $833
+         sta   $83B
+         sta   $841
+         ldx   #$FA
+         stx   $834
+         lda   #$EA
+         sta   $835
+         sta   $83D
+         sta   $843
+         inx
+         stx   $83C
+         lda   #3
+         sta   $842
+@exit
+         rts