From a4392d5df9dd100344245ee7a1210a126ac0a014 Mon Sep 17 00:00:00 2001
From: Gyorgy Szombathelyi <gyurco@freemail.hu>
Date: Wed, 11 Mar 2020 20:06:38 +0100
Subject: [PATCH] TraverseUSA: add a PAL/original timings switch

---
 .../TraverseUSA_MiST/rtl/TraverseUSA_MiST.sv               | 3 +++
 .../IremM52 Hardware/TraverseUSA_MiST/rtl/traverse_usa.vhd | 7 ++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Arcade_MiST/IremM52 Hardware/TraverseUSA_MiST/rtl/TraverseUSA_MiST.sv b/Arcade_MiST/IremM52 Hardware/TraverseUSA_MiST/rtl/TraverseUSA_MiST.sv
index ad291209..c7963b9a 100644
--- a/Arcade_MiST/IremM52 Hardware/TraverseUSA_MiST/rtl/TraverseUSA_MiST.sv	
+++ b/Arcade_MiST/IremM52 Hardware/TraverseUSA_MiST/rtl/TraverseUSA_MiST.sv	
@@ -57,6 +57,7 @@ localparam CONF_STR = {
 	`CORE_NAME,";;",
 	"O2,Rotate Controls,Off,On;",
 	"O34,Scanlines,Off,25%,50%,75%;",
+	"O1,Video Timing,Original,Pal 50Hz;",
 	"OA,Blending,Off,On;",
 	"O5,Units,MP,Km;",
 	"O6,Freeze,Disable,Enable;",
@@ -70,6 +71,7 @@ localparam CONF_STR = {
 wire       rotate = status[2];
 wire [1:0] scanlines = status[4:3];
 wire       blend = status[10];
+wire       pal = status[1];
 
 reg        shtrider = 0;
 wire [7:0] dip1 = 8'hff;
@@ -235,6 +237,7 @@ traverse_usa traverse_usa (
 	.clock_0p895  ( clk_aud         ),
 	.reset        ( reset 				  ),
 
+	.palmode      ( pal             ),
 	.shtrider     ( shtrider        ),
 	
 	.video_r      ( r               ),
diff --git a/Arcade_MiST/IremM52 Hardware/TraverseUSA_MiST/rtl/traverse_usa.vhd b/Arcade_MiST/IremM52 Hardware/TraverseUSA_MiST/rtl/traverse_usa.vhd
index 6ebb5365..b44f628b 100644
--- a/Arcade_MiST/IremM52 Hardware/TraverseUSA_MiST/rtl/traverse_usa.vhd	
+++ b/Arcade_MiST/IremM52 Hardware/TraverseUSA_MiST/rtl/traverse_usa.vhd	
@@ -113,6 +113,7 @@ port(
  clock_0p895  : in std_logic;
  reset        : in std_logic;
 
+ palmode        : in std_logic; -- 50 Hz vfreq
  shtrider       : in std_logic; -- Shot Rider mode
 -- tv15Khz_mode : in std_logic;
  video_r        : out std_logic_vector(1 downto 0);
@@ -334,7 +335,11 @@ begin
 				hcnt <= '0'&x"80";
 				vcnt <= vcnt + 1;
 				if vcnt = '1'&x"FF" then
-					vcnt <= '0'&x"E6";  -- from M52 schematics
+					if palmode = '0' then
+						vcnt <= '0'&x"E6";  -- from M52 schematics
+					else
+						vcnt <= '0'&x"C8";
+					end if;
 				end if;
 			end if;
 		end if;