From e9dfdcd49588923dc8c0381defe67f5d74683d08 Mon Sep 17 00:00:00 2001
From: Newsdee <newsdee@gmail.com>
Date: Sun, 9 Oct 2016 19:40:51 +0800
Subject: [PATCH] Added option to switch palette between FCEUX (very common)
 and Unsaturated-V6 (very close to NTSC).

---
 cores/nes/mist/NES_mist.v                   | 20 ++++---
 cores/nes/src/nes_palette_fceux.txt         | 64 +++++++++++++++++++++
 cores/nes/src/nes_palette_unsaturatedv6.txt | 64 +++++++++++++++++++++
 cores/nes/src/video.v                       | 23 ++++++--
 4 files changed, 157 insertions(+), 14 deletions(-)
 create mode 100644 cores/nes/src/nes_palette_fceux.txt
 create mode 100644 cores/nes/src/nes_palette_unsaturatedv6.txt

diff --git a/cores/nes/mist/NES_mist.v b/cores/nes/mist/NES_mist.v
index 1b79f0a..92e35a0 100644
--- a/cores/nes/mist/NES_mist.v
+++ b/cores/nes/mist/NES_mist.v
@@ -158,13 +158,12 @@ parameter CONF_STR = {
 			"O2,Scanlines,OFF,ON;",
 			"O3,Invert mirroring,OFF,ON;",
 			"O4,Hide overscan,OFF,ON;",
-			"T5,Start;",
-			"T6,Select;",
-			"T7,Reset;",
+			"O5,Palette,FCEUX,Unsaturated-V6;",
+			"T6,Reset;",
 			"V,v0.8;"
 };
 
-parameter CONF_STR_LEN = 8+25+20+27+24+9+10+9+7;
+parameter CONF_STR_LEN = 8+25+20+27+24+32+9+7;
 wire [7:0] status;
 
 wire arm_reset = status[0];
@@ -172,13 +171,17 @@ wire smoothing_osd = status[1];
 wire scanlines_osd = status[2];
 wire mirroring_osd = status[3];
 wire overscan_osd = status[4];
-wire start_osd = status[5];
-wire select_osd = status[6];
-wire reset_osd = status[7];
+wire palette2_osd = status[5];
+wire reset_osd = status[6];
+
+// no longer used
+wire start_osd = 0;
+wire select_osd = 0;
 
 wire scandoubler_disable;
 wire ps2_kbd_clk, ps2_kbd_data;
 
+
 user_io #(.STRLEN(CONF_STR_LEN)) user_io(
    .conf_str(CONF_STR),
    // the spi interface
@@ -431,7 +434,8 @@ video video (
 	.smoothing(!smoothing_osd),
 	.scanlines(scanlines_osd),
 	.overscan(overscan_osd),
-
+	.palette(palette2_osd),
+	
 	.VGA_HS(VGA_HS),
 	.VGA_VS(VGA_VS),
 	.VGA_R(VGA_R),
diff --git a/cores/nes/src/nes_palette_fceux.txt b/cores/nes/src/nes_palette_fceux.txt
new file mode 100644
index 0000000..2f34139
--- /dev/null
+++ b/cores/nes/src/nes_palette_fceux.txt
@@ -0,0 +1,64 @@
+39ce
+4464
+5400
+4c08
+3811
+0815
+0014
+002f
+00a8
+0100
+0140
+08e0
+2ce3
+0000
+0000
+0000
+5ef7
+75c0
+74e4
+7810
+5c17
+2c1c
+00bb
+0539
+01d1
+0240
+02a0
+1e40
+4600
+0000
+0000
+0000
+7fff
+7ee7
+7e4b
+7e28
+7dfe
+59df
+31df
+1e7f
+1efe
+0b50
+2769
+4feb
+6fa0
+3def
+0000
+0000
+7fff
+7f95
+7f58
+7f3a
+7f1f
+6f1f
+5aff
+577f
+539f
+53fc
+5fd5
+67f6
+7bf3
+6318
+0000
+0000
diff --git a/cores/nes/src/nes_palette_unsaturatedv6.txt b/cores/nes/src/nes_palette_unsaturatedv6.txt
new file mode 100644
index 0000000..aea4d79
--- /dev/null
+++ b/cores/nes/src/nes_palette_unsaturatedv6.txt
@@ -0,0 +1,64 @@
+35ad
+4060
+4823
+4027
+302b
+140b
+004a
+0068
+00c6
+0121
+0120
+0d00
+2ce0
+0000
+0000
+0000
+5ad6
+6943
+74c9
+748e
+5873
+3074
+0cb4
+0130
+01ac
+0205
+0220
+2200
+49e0
+0000
+0000
+0000
+7fff
+7eac
+7e32
+7dd7
+7ddc
+65be
+361e
+167b
+02f7
+0350
+1f6b
+3f49
+6729
+294a
+0000
+0000
+7fff
+7f98
+7f5a
+7f3c
+7f3f
+7b3f
+635f
+577e
+4fbd
+4fda
+5bd7
+67d6
+77d6
+5ef7
+0000
+0000
\ No newline at end of file
diff --git a/cores/nes/src/video.v b/cores/nes/src/video.v
index 9fe2451..76f8d3c 100644
--- a/cores/nes/src/video.v
+++ b/cores/nes/src/video.v
@@ -10,6 +10,7 @@ module video(
 	input smoothing,
 	input scanlines,
 	input overscan,
+	input palette,
 	
 	input sck,
 	input ss,
@@ -49,10 +50,20 @@ osd #(10'd0, 10'd0, 3'd4) osd (
 );
 
 // NES Palette -> RGB555 conversion
-reg [15:0] pallut[0:63];
-initial $readmemh("nes_palette.txt", pallut);
-wire [14:0] pixel = pallut[color][14:0];
+reg [15:0] pal_lut[0:63];
+initial $readmemh("nes_palette_original.txt", pal_lut); // MiST legacy 
 
+// NTSC UnsaturatedV6 palette
+//see: http://www.firebrandx.com/nespalette.html
+reg [15:0] pal_unsat_lut[0:63];
+initial $readmemh("nes_palette_unsaturatedv6.txt", pal_unsat_lut);
+
+// FCEUX palette
+reg [15:0] pal_fcelut[0:63];
+initial $readmemh("nes_palette_fceux.txt", pal_fcelut);
+
+wire [14:0] pixel = palette ?  pal_unsat_lut[color][14:0] : pal_fcelut[color][14:0];
+ 
 // Horizontal and vertical counters
 reg [9:0] h, v;
 wire hpicture  = (h < 512);             // 512 lines of picture
@@ -86,9 +97,9 @@ wire darker = !mode && v[0] && scanlines;
 // display overlay to hide overscan area
 // based on Mario3, DoubleDragon2, Shadow of the Ninja
 wire ol = overscan && ( (h > 512-16) || 
-								(h < 18) || 
-								(v < 8) || 
-								( v > (mode? 240-10 : 480-20) ) 
+								(h < 20) || 
+								(v < (mode ? 6 : 12)) || 
+								(v > (mode ? 240-10 : 480-20)) 
 							  );
 
 wire  [4:0]   vga_r = ol ? {4'b0, pixel_v[4:4]}   : (darker ? {1'b0, pixel_v[4:1]} : pixel_v[4:0]);