From f034861757f2327f853a50ee4e8494d47326bdc9 Mon Sep 17 00:00:00 2001
From: Squid <squid12345678@gmail.com>
Date: Tue, 21 Feb 2017 11:28:49 +0000
Subject: [PATCH] Fix missing OSD on RGB 15khz. Fix dull colours on RGB 15khz

---
 cores/bbc/fpga/mist/bbc_mist_top.v |  6 ++++--
 cores/bbc/fpga/mist/osd.v          | 18 ++++++++++++++----
 2 files changed, 18 insertions(+), 6 deletions(-)
 mode change 100644 => 100755 cores/bbc/fpga/mist/bbc_mist_top.v
 mode change 100644 => 100755 cores/bbc/fpga/mist/osd.v

diff --git a/cores/bbc/fpga/mist/bbc_mist_top.v b/cores/bbc/fpga/mist/bbc_mist_top.v
old mode 100644
new mode 100755
index a3fd38a..823352c
--- a/cores/bbc/fpga/mist/bbc_mist_top.v
+++ b/cores/bbc/fpga/mist/bbc_mist_top.v
@@ -109,7 +109,7 @@ clockgen CLOCKS(
 
 // without scan doubler only half the pixel clock is used
 reg clk_12m;
-always @(clk_24m)
+always @(posedge clk_24m)
 	clk_12m <= !clk_12m;
 
 wire clk_osd = scandoubler_disable?clk_12m:clk_24m;
@@ -133,7 +133,9 @@ osd #(0,0,4) OSD (
    .green_out  ( VGA_G        ),
    .blue_out   ( VGA_B        ),
    .hs_out     ( v_hs         ),
-   .vs_out     ( v_vs         )
+   .vs_out     ( v_vs         ),
+
+   .tv15khz    ( scandoubler_disable )
 );
 
 wire v_hs, v_vs;
diff --git a/cores/bbc/fpga/mist/osd.v b/cores/bbc/fpga/mist/osd.v
old mode 100644
new mode 100755
index 4f0f650..f851698
--- a/cores/bbc/fpga/mist/osd.v
+++ b/cores/bbc/fpga/mist/osd.v
@@ -45,7 +45,9 @@ module osd (
 	output [5:0]  	green_out,
 	output [5:0]  	blue_out,
 	output			hs_out,
-	output			vs_out
+	output			vs_out,
+
+    input           tv15khz
 );
 
 parameter OSD_X_OFFSET = 10'd0;
@@ -194,9 +196,17 @@ always @(posedge pclk)
   osd_byte <= osd_buffer[{osd_vcnt[6:4], osd_hcnt}];
 
 wire [2:0] osd_color = OSD_COLOR;
-assign red_out   = !osd_de? {3{red_in}}     :  {osd_pixel, osd_pixel, osd_color[2], {red_in, red_in[1]}  };
-assign green_out = !osd_de? {3{green_in}}   :  {osd_pixel, osd_pixel, osd_color[1], {green_in, green_in[1]} };
-assign blue_out  = !osd_de? {3{blue_in}}    :  {osd_pixel, osd_pixel, osd_color[0], {blue_in, blue_in[1]} };
+
+// RGB 15khz output is different to fix dull colours, VGA not affected.
+// BBC only uses one bit per colour but video engine uses a 2-bit vector, MSB is only used.
+// BBC has a fixed palette of 8 colours.
+wire [5:0] r_in = tv15khz? {5{red_in[0]}}   : {3{red_in}};
+wire [5:0] g_in = tv15khz? {5{green_in[0]}} : {3{green_in}};
+wire [5:0] b_in = tv15khz? {5{blue_in[0]}}  : {3{blue_in}};
+
+assign red_out   = !osd_de? r_in :  {osd_pixel, osd_pixel, osd_color[2], {red_in, red_in[1]}  };
+assign green_out = !osd_de? g_in :  {osd_pixel, osd_pixel, osd_color[1], {green_in, green_in[1]} };
+assign blue_out  = !osd_de? b_in :  {osd_pixel, osd_pixel, osd_color[0], {blue_in, blue_in[1]} };
 
 assign hs_out = hs_in;
 assign vs_out = vs_in;