diff --git a/SNES.sv b/SNES.sv
index 153f78a..a9f211c 100644
--- a/SNES.sv
+++ b/SNES.sv
@@ -57,6 +57,7 @@ module emu
 	input  [11:0] HDMI_HEIGHT,
 	output        HDMI_FREEZE,
 	output        HDMI_BLACKOUT,
+	output        HDMI_BOB_DEINT,
 
 `ifdef MISTER_FB
 	// Use framebuffer in DDRAM
@@ -187,6 +188,7 @@ assign VGA_SCALER= 0;
 assign VGA_DISABLE = 0;
 assign HDMI_FREEZE = 0;
 assign HDMI_BLACKOUT = 0;
+assign HDMI_BOB_DEINT = 0;
 
 assign {SD_SCK, SD_MOSI, SD_CS} = 'Z;
 
diff --git a/sys/ascal.vhd b/sys/ascal.vhd
index a79f7ec..5607e64 100644
--- a/sys/ascal.vhd
+++ b/sys/ascal.vhd
@@ -201,9 +201,10 @@ ENTITY ascal IS
 		i_vdmax : OUT natural RANGE 0 TO 4095;
 
 		-- Output video parameters
-		run    : IN std_logic :='1'; -- 1=Enable output image. 0=No image
-		freeze : IN std_logic :='0'; -- 1=Disable framebuffer writes
-		mode   : IN unsigned(4 DOWNTO 0);
+		run       : IN std_logic :='1'; -- 1=Enable output image. 0=No image
+		freeze    : IN std_logic :='0'; -- 1=Disable framebuffer writes
+		mode      : IN unsigned(4 DOWNTO 0);
+ 		bob_deint : IN std_logic := '0';
 		-- SYNC  |_________________________/"""""""""\_______|
 		-- DE    |""""""""""""""""""\________________________|
 		-- RGB   |    <#IMAGE#>      ^HDISP                  |
@@ -319,6 +320,7 @@ ARCHITECTURE rtl OF ascal IS
 	SIGNAL i_pvs,i_pfl,i_pde,i_pce : std_logic;
 	SIGNAL i_ppix : type_pix;
 	SIGNAL i_freeze : std_logic;
+	SIGNAL i_bob_deint : std_logic;
 	SIGNAL i_count : unsigned(2 DOWNTO 0);
 	SIGNAL i_hsize,i_hmin,i_hmax,i_hcpt : uint12;
 	SIGNAL i_hrsize,i_vrsize : uint12;
@@ -334,6 +336,7 @@ ARCHITECTURE rtl OF ascal IS
 	SIGNAL i_de_delay : natural RANGE 0 TO 31;
 	SIGNAL i_intercnt : natural RANGE 0 TO 3;
 	SIGNAL i_inter,i_half,i_flm : std_logic;
+	SIGNAL i_wfl : std_logic_vector(2 DOWNTO 0);
 	SIGNAL i_write,i_wreq,i_alt,i_line,i_wline,i_wline_mem : std_logic;
 	SIGNAL i_walt,i_walt_mem,i_wreq_mem : std_logic;
 	SIGNAL i_wdelay : natural RANGE 0 TO 7;
@@ -411,6 +414,8 @@ ARCHITECTURE rtl OF ascal IS
 	-- Output
 	SIGNAL o_run : std_logic;
 	SIGNAL o_freeze : std_logic;
+	SIGNAL o_bob_deint : std_logic;
+	SIGNAL o_iwfl : std_logic_vector(2 DOWNTO 0);
 	SIGNAL o_mode,o_hmode,o_vmode : unsigned(4 DOWNTO 0);
 	SIGNAL o_format : unsigned(5 DOWNTO 0);
 	SIGNAL o_fb_pal_dr : unsigned(23 DOWNTO 0);
@@ -1132,6 +1137,7 @@ BEGIN
 			i_pushhead<='0';
 			i_eol<='0'; -- End Of Line
 			i_freeze <=freeze; -- <ASYNC>
+			i_bob_deint <= bob_deint;
 			i_iauto<=iauto; -- <ASYNC>
 			i_wreq<='0';
 			i_wr<='0';
@@ -1192,11 +1198,13 @@ BEGIN
 					i_vcpt<=0;
 					IF i_inter='1' AND i_flm='0' AND i_half='0' AND INTER THEN
 						i_line<='1';
+						i_wfl(o_ibuf1) <= '0';
 						i_adrsi<=to_unsigned(N_BURST * i_hburst,32) +
 									to_unsigned(N_BURST * to_integer(
 									unsigned'("00") & to_std_logic(HEADER)),32);
 					ELSE
 						i_line<='0';
+						i_wfl(o_ibuf0) <= '1';
 						i_adrsi<=to_unsigned(N_BURST * to_integer(
 									 unsigned'("00") & to_std_logic(HEADER)),32);
 					END IF;
@@ -1206,8 +1214,8 @@ BEGIN
 														i_vcpt>=i_vmin AND i_vcpt<=i_vmax);
 
 				-- Detects end of frame for triple buffering.
-				i_endframe0<=i_vs AND (NOT i_inter OR i_flm);
-				i_endframe1<=i_vs AND (NOT i_inter OR NOT i_flm);
+				i_endframe0<=i_vs AND (NOT i_inter OR i_flm OR i_bob_deint);
+				i_endframe1<=i_vs AND (NOT i_inter OR NOT i_flm OR i_bob_deint);
 
 				i_vss<=to_std_logic(i_vcpt>=i_vmin AND i_vcpt<=i_vmax);
 
@@ -1864,6 +1872,8 @@ BEGIN
 			o_isync <= '0';
 			o_isync2 <= o_isync;
 			o_freeze <= freeze;
+			o_bob_deint <= bob_deint;
+			o_iwfl <= i_wfl;
 			o_inter  <=i_inter; -- <ASYNC>
 			o_iendframe0<=i_endframe0; -- <ASYNC>
 			o_iendframe02<=o_iendframe0;
@@ -2096,7 +2106,26 @@ BEGIN
 			o_read<=o_read_pre AND o_run;
 			o_rline<=o_vacpt(0); -- Even/Odd line for interlaced video
 
-			o_adrs_pre<=to_integer(o_vacpt) * to_integer(o_stride);
+			----
+			-- When bob deinterlacing we read lines from one buffer (the most current) but we read them twice
+			-- (in contrast to weave deinterlacing where we read each 480p line from alternating buffers)
+			-- To counteract the severe vibrating/motion with bob deinterlacing, we need to offset one field
+			-- by a half-line. This is done by only reading the first line of the 'even' frame once
+
+			IF o_inter='1' AND o_bob_deint='1' THEN
+				IF o_iwfl(o_obuf0)='0' THEN
+					IF o_vacpt=0 OR o_rline='1' THEN
+						o_adrs_pre <= to_integer(o_vacpt) * to_integer(o_stride);
+					ELSE
+						o_adrs_pre <= (to_integer(o_vacpt)-1) * to_integer(o_stride);
+					END IF;
+				ELSE
+					o_adrs_pre <= to_integer(o_vacpt(11 DOWNTO 1) & "0") * to_integer(o_stride);
+				END IF;
+			ELSE
+				o_adrs_pre<=to_integer(o_vacpt) * to_integer(o_stride);
+			END IF;
+
 			IF o_adrsa='1' THEN
 				IF o_fload=2 THEN
 					o_adrs<=to_unsigned(o_hbcpt * N_BURST,32);
diff --git a/sys/sys_top.v b/sys/sys_top.v
index 5b20846..18f3969 100644
--- a/sys/sys_top.v
+++ b/sys/sys_top.v
@@ -679,6 +679,7 @@ wire         vbuf_write;
 wire  [23:0] hdmi_data;
 wire         hdmi_vs, hdmi_hs, hdmi_de, hdmi_vbl, hdmi_brd;
 wire         freeze;
+wire         bob_deint;
 
 `ifndef MISTER_DEBUG_NOHDMI
 	wire clk_hdmi  = hdmi_clk_out;
@@ -710,9 +711,10 @@ wire         freeze;
 	)
 	ascal
 	(
-		.reset_na (~reset_req),
-		.run      (1),
-		.freeze   (freeze),
+		.reset_na   (~reset_req),
+		.run        (1),
+		.freeze     (freeze),
+		.bob_deint  (bob_deint),
 
 		.i_clk    (clk_ihdmi),
 		.i_ce     (ce_hpix),
@@ -1738,6 +1740,7 @@ emu emu
 	.HDMI_HEIGHT(direct_video ? 12'd0 : hdmi_height),
 	.HDMI_FREEZE(freeze),
 	.HDMI_BLACKOUT(hdmi_blackout),
+	.HDMI_BOB_DEINT(bob_deint),
 
 	.CLK_VIDEO(clk_vid),
 	.CE_PIXEL(ce_pix),