Fix color expansion without the scandoubler

Board/mist/mist.vhd

@@ -1,5 +1,10 @@
+-- user_io
+-- Interface to the MiST IO Controller
+
+-- mist_video
 -- A video pipeline for MiST. Just insert between the core video output and the VGA pins
 -- Provides an optional scandoubler, a rotateable OSD and (optional) RGb->YPbPr conversion
+
 library IEEE;
 use IEEE.std_logic_1164.all;
 use IEEE.numeric_std.all;
@@ -45,6 +50,10 @@ component user_io
 
 	ps2_kbd_clk       : out std_logic;
 	ps2_kbd_data      : out std_logic;
+	key_pressed       : out std_logic;
+	key_extended      : out std_logic;
+	key_code          : out std_logic_vector(7 downto 0);
+	key_strobe        : out std_logic;
 
 	ps2_mouse_clk     : out std_logic;
 	ps2_mouse_data    : out std_logic;

Board/mist/mist_video.v

@@ -42,14 +42,38 @@ parameter OSD_COLOR    = 3'd4;
 parameter OSD_X_OFFSET = 10'd0;
 parameter OSD_Y_OFFSET = 10'd0;
 parameter SD_HCNT_WIDTH = 9;
-parameter COLOR_DEPTH = 6; // 3-6
+parameter COLOR_DEPTH = 6; // 1-6
 
 wire [5:0] SD_R_O;
 wire [5:0] SD_G_O;
 wire [5:0] SD_B_O;
 wire       SD_HS_O;
 wire       SD_VS_O;
 
+reg  [5:0] R_full;
+reg  [5:0] G_full;
+reg  [5:0] B_full;
+
+always @(*) begin
+	if (COLOR_DEPTH == 6) begin
+		R_full = R;
+		G_full = G;
+		B_full = B;
+	end else if (COLOR_DEPTH == 2) begin
+		R_full = {3{R}};
+		G_full = {3{G}};
+		B_full = {3{B}};
+	end else if (COLOR_DEPTH == 1) begin
+		R_full = {6{R}};
+		G_full = {6{G}};
+		B_full = {6{B}};
+	end else begin
+		R_full = { R, R[COLOR_DEPTH-1 -:(6-COLOR_DEPTH)] };
+		G_full = { G, G[COLOR_DEPTH-1 -:(6-COLOR_DEPTH)] };
+		B_full = { B, B[COLOR_DEPTH-1 -:(6-COLOR_DEPTH)] };
+	end
+end
+
 scandoubler #(SD_HCNT_WIDTH, COLOR_DEPTH) scandoubler
 (
 	.clk_sys   ( clk_sys   ),
@@ -77,9 +101,9 @@ osd #(OSD_X_OFFSET, OSD_Y_OFFSET, OSD_COLOR) osd
 	.SPI_DI  ( SPI_DI  ),
 	.SPI_SCK ( SPI_SCK ),
 	.SPI_SS3 ( SPI_SS3 ),
-	.R_in    ( scandoubler_disable ? R : SD_R_O ),
-	.G_in    ( scandoubler_disable ? G : SD_G_O ),
-	.B_in    ( scandoubler_disable ? B : SD_B_O ),
+	.R_in    ( scandoubler_disable ? R_full : SD_R_O ),
+	.G_in    ( scandoubler_disable ? G_full : SD_G_O ),
+	.B_in    ( scandoubler_disable ? B_full : SD_B_O ),
 	.HSync   ( scandoubler_disable ? HSync : SD_HS_O ),
 	.VSync   ( scandoubler_disable ? VSync : SD_VS_O ),
 	.R_out   ( osd_r_o ),

Board/mist/scandoubler.v

@@ -74,6 +74,14 @@ always @(*) begin
 		b = sd_out[5:0];
 		g = sd_out[11:6];
 		r = sd_out[17:12];
+	end else if (COLOR_DEPTH == 2) begin
+		b = {3{sd_out[1:0]}};
+		g = {3{sd_out[3:2]}};
+		r = {3{sd_out[5:4]}};
+	end else if (COLOR_DEPTH == 1) begin
+		b = {6{sd_out[0]}};
+		g = {6{sd_out[1]}};
+		r = {6{sd_out[2]}};
 	end else begin
 		b = { sd_out[COLOR_DEPTH-1:0], sd_out[COLOR_DEPTH-1 -:(6-COLOR_DEPTH)] };
 		g = { sd_out[COLOR_DEPTH*2-1:COLOR_DEPTH], sd_out[COLOR_DEPTH*2-1 -:(6-COLOR_DEPTH)] };

Board/mist/user_io.v

@@ -69,6 +69,12 @@ module user_io #(parameter STRLEN=0, parameter PS2DIV=100) (
 	output              ps2_mouse_clk,
 	output reg          ps2_mouse_data,
 
+	// keyboard data
+	output reg          key_pressed,  // 1-make (pressed), 0-break (released)
+	output reg          key_extended, // extended code
+	output reg    [7:0] key_code,     // key scan code
+	output reg          key_strobe,   // key data valid
+
 	// mouse data
 	output reg    [8:0] mouse_x,
 	output reg    [8:0] mouse_y,
@@ -383,12 +389,16 @@ always @(posedge clk_sys) begin
 	reg [7:0] mouse_flags_r;
 	reg [7:0] mouse_x_r;
 
+	reg       key_pressed_r;
+	reg       key_extended_r;
+
 	//synchronize between SPI and sys clock domains
 	spi_receiver_strobeD <= spi_receiver_strobe_r;
 	spi_receiver_strobe <= spi_receiver_strobeD;
 	spi_transfer_endD	<= spi_transfer_end_r;
 	spi_transfer_end	<= spi_transfer_endD;
 
+	key_strobe <= 0;
 	mouse_strobe <= 0;
 
 	if (~spi_transfer_endD & spi_transfer_end) begin
@@ -427,6 +437,18 @@ always @(posedge clk_sys) begin
 					// store incoming ps2 keyboard bytes 
 					ps2_kbd_fifo[ps2_kbd_wptr] <= spi_byte_in;
 					ps2_kbd_wptr <= ps2_kbd_wptr + 1'd1;
+					if (abyte_cnt == 1) begin
+						key_extended_r <= 0;
+						key_pressed_r <= 1;
+					end
+					if (spi_byte_in == 8'he0) key_extended_r <= 1'b1;
+					else if (spi_byte_in == 8'hf0) key_pressed_r <= 1'b0;
+					else begin
+						key_extended <= key_extended_r;
+						key_pressed <= key_pressed_r || abyte_cnt == 1;
+						key_code <= spi_byte_in;
+						key_strobe <= 1'b1;
+					end
 				end
 
 				// joystick analog