diff --git a/examples/graphbench.pas b/examples/graphbench.pas
deleted file mode 100644
index 327e72e..0000000
--- a/examples/graphbench.pas
+++ /dev/null
@@ -1,92 +0,0 @@
-program graphbench;
-var starttime,endtime:DateTime;
-
-procedure startBench(name:string);
-begin
-	write(name:20, ' ');
-	starttime := GetTime;
-end;
-
-procedure endBench;
-var secDelta, minDelta, hourDelta:integer;
-  procedure write2Digits(i:integer);
-  begin
-	if i < 10 then
-		write('0');
-		write(i);
-  end;
-begin
-	endTime := GetTime;
-
-	hourDelta := endtime.hours - starttime.hours;
-	minDelta  := endtime.minutes - starttime.minutes;
-	secDelta  := endtime.seconds - starttime.seconds;
-
-	if secDelta < 0 then
-	begin
-		secDelta := 60 + secDelta;
-		minDelta := minDelta - 1;
-	end;
-
-	if minDelta < 0 then
-	begin
-		minDelta := 60 + minDelta;
-		hourDelta := hourDelta - 1;
-	end;
-
-	write2Digits(hourDelta);
-	write(':'); write2Digits(minDelta);
-	write(':'); write2Digits(secDelta);
-	writeln;
-end;
-
-function randint(lessthan:integer):integer;
-var r:integer;
-begin
-	r := random and 511;
-	if r >= lessthan then
-		r := r - lessthan;
-	randint := r;
-end;
-
-procedure drawlines(count:integer);
-var i,col,x1,y1,x2,y2:integer;
-begin
-	col := 1;
-	for i := 1 to count do
-	begin
-		x1 := randint(500);
-		y1 := randint(400);
-		x2 := randint(500);
-		y2 := randint(400);
-		DrawLine(x1,y1,x2,y2,col);
-		col := col + 1;
-		if col > 15 then col := 1;
-	end;
-end;
-
-procedure drawpoints(count:integer);
-var i,col,x,y:integer;
-begin
-	col := 1;
-	for i := 1 to count do
-	begin
-		x := randint(500);
-		y := randint(400);
-		PutPixel(x,y,col);
-		col := col + 1;
-		if col > 15 then col := 1;
-	end;
-end;
-
-begin
-	InitGraphics;
-	startBench('200K points');
-	drawpoints(200000);
-	endBench;
-
-	InitGraphics;
-	startBench('10K lines');
-	drawlines(10000);
-	endBench;
-end.
diff --git a/lib/corelib.s b/lib/corelib.s
index 93dc81f..a21b95c 100644
--- a/lib/corelib.s
+++ b/lib/corelib.s
@@ -706,32 +706,108 @@ CMPWORDS_XT2:
 	.EQU FB_PS	$90C
 	.EQU FB_PD	$910
 	.EQU FB_CTL	$914
-	.EQU FB_SHIFTER $918
-	.EQU FB_SHIFTCOUNT $91C
-	.EQU FB_SHIFTERM $920
-	.EQU FB_SHIFTERSP $924
-	.EQU FB_MASKGEN $928
+; set a pixel in fb memory
+; parameters: x,y - coordinates
+PUTPIXEL_1BPP:
+	; calculate vmem address:
+	OVER ; duplicate x
+	; divide x by 32
+	SHR
+	SHR
+	SHR
+	SHR
+	SHR
+	SWAP
+	; multiply y by words per line
+	SHL 2
+	SHL 2
+	SHL
 
-; draw a single pixel
-; args: x, y, color
+	ADD ; add results together for vmem addr
 
+	DUP
+	LOADCP FB_WA
+	SWAP
+	STOREI	; store to framebuffer write addr register
+	DROP
+	LOADCP FB_RA ; and to framebuffer read addr register
+	SWAP
+	STOREI
+	DROP
+
+	; x is now at top of stack
+	; get bit value from x modulo 32
+	LOADC 31
+	AND
+	SHL 2 ; (x & 31) * 4 = offset into table
+	LOADCP INT_TO_PIX_TABLE
+	ADD
+	LOADI
+
+	LOADCP FB_IO
+	; read old vmem value
+	LOADCP FB_IO
+	LOADI
+	; or in new bit
+	OR
+	; write new value
+	STOREI
+	DROP
+
+	RET
+
+INT_TO_PIX_TABLE:
+	.WORD %10000000_00000000_00000000_00000000
+	.WORD %01000000_00000000_00000000_00000000
+	.WORD %00100000_00000000_00000000_00000000
+	.WORD %00010000_00000000_00000000_00000000
+	.WORD %00001000_00000000_00000000_00000000
+	.WORD %00000100_00000000_00000000_00000000
+	.WORD %00000010_00000000_00000000_00000000
+	.WORD %00000001_00000000_00000000_00000000
+	.WORD %00000000_10000000_00000000_00000000
+	.WORD %00000000_01000000_00000000_00000000
+	.WORD %00000000_00100000_00000000_00000000
+	.WORD %00000000_00010000_00000000_00000000
+	.WORD %00000000_00001000_00000000_00000000
+	.WORD %00000000_00000100_00000000_00000000
+	.WORD %00000000_00000010_00000000_00000000
+	.WORD %00000000_00000001_00000000_00000000
+	.WORD %00000000_00000000_10000000_00000000
+	.WORD %00000000_00000000_01000000_00000000
+	.WORD %00000000_00000000_00100000_00000000
+	.WORD %00000000_00000000_00010000_00000000
+	.WORD %00000000_00000000_00001000_00000000
+	.WORD %00000000_00000000_00000100_00000000
+	.WORD %00000000_00000000_00000010_00000000
+	.WORD %00000000_00000000_00000001_00000000
+	.WORD %00000000_00000000_00000000_10000000
+	.WORD %00000000_00000000_00000000_01000000
+	.WORD %00000000_00000000_00000000_00100000
+	.WORD %00000000_00000000_00000000_00010000
+	.WORD %00000000_00000000_00000000_00001000
+	.WORD %00000000_00000000_00000000_00000100
+	.WORD %00000000_00000000_00000000_00000010
+	.WORD %00000000_00000000_00000000_00000001
+
+PUTMPIXEL:
+	LOADC 1
+; set a pixel in fb memory
+; parameters: x,y,color - coordinates, color value (0-15)
 PUTPIXEL:
 PUTPIXEL_4BPP:
 	.EQU PUTPIXEL_X 0
 	.EQU PUTPIXEL_Y 4
 	.EQU PUTPIXEL_COLOR 8
-	.EQU PUTPIXEL_BPSAV 12
+	.EQU PUTPIXEL_PIXPOS 12
 	.EQU PUTPIXEL_FS 16
 
 	FPADJ -PUTPIXEL_FS
+
 	STORE PUTPIXEL_COLOR
 	STORE PUTPIXEL_Y
 	STORE PUTPIXEL_X
 
-	LOADREG BP
-	STORE PUTPIXEL_BPSAV
-	LOADC 0
-	STOREREG BP
 
 	; calculate vmem address: (x / 8) + (y * 80)
 	LOAD PUTPIXEL_X
@@ -750,36 +826,83 @@ PUTPIXEL_4BPP:
 
 	ADD ; add results together for vmem addr
 
-	DUP
-	STORE.B FB_WA	; set as write and read addresses
-	STORE.B FB_RA
+	LOADCP FB_WA
+	OVER
+	STOREI	; store to framebuffer write addr register
+	DROP
+	LOADCP FB_RA ; and to framebuffer read addr register
+	SWAP	; swap addr and value for STOREI
+	STOREI
+	DROP
+
+	LOAD PUTPIXEL_X
+	;		|0000.0000|0000.0000|0000.0000|0000.1111|
+	LOADC 7
+	AND		; calculate pixel position in word
+	LOADC 7
+	SWAP
+	SUB		; pixpos = 7 - (x & 7)
+	STORE PUTPIXEL_PIXPOS
 
-	; create pixel data from color value in
-	; leftmost pixel data bits (31-28)
-	LOADC 0
 	LOAD PUTPIXEL_COLOR
-	BPLC
+	LOAD PUTPIXEL_PIXPOS
+	SHR		; rcount = pixpos / 2
+ROTLOOP_:
+	DUP		; exit loop if rcount is 0
+	CBRANCH.Z ROTLOOP_END
+	SWAP		; pixel value is now on top of stack
+	BROT		; value = value << 8
+	SWAP		; rcount is now on top of stack
+	DEC 1		; rcount = rcount - 1
+	BRANCH ROTLOOP_
+ROTLOOP_END:
+	DROP		; drop rcount
+	; shifted pixel value is now at top of stack
+	LOAD PUTPIXEL_PIXPOS
+	LOADC 1
+	AND
+	CBRANCH.Z EVEN_PIXPOS
+	SHL 2	; if pixpos is odd, shift by 4 bits
 	SHL 2
-	SHL 2
-	STORE.B FB_SHIFTER	; store pixel into shifter
+EVEN_PIXPOS:
+	LOAD PUTPIXEL_X
+	; get bit value from x modulo 8
+	LOADC 7
+	AND
+	SHL 2 ; (x & 7) * 4 = offset into table
+	LOADCP INT_TO_MASK_TABLE
+	ADD
+	LOADI
 
-	LOAD PUTPIXEL_X 	; use x coord as shift count
-	STORE.B FB_SHIFTCOUNT	; writing triggers shifting
+	; read old vmem value
+	LOADCP FB_IO
+	LOADI
+	; mask bits
+	AND
+	; or in shifted pixel value
+	OR
 
-	LOAD.B FB_SHIFTERM	; get shift result as mask
-	LOAD.B FB_IO		; get background pixel data
-	AND			; remove bits for new pixel from bg
-
-	LOAD.B FB_SHIFTER	; load shifted pixel
-	OR			; OR in new pixel bits
-	STORE.B FB_IO		; write new pixel data word to vmem
-
-	LOAD PUTPIXEL_BPSAV
-	STOREREG BP
+	; write new value
+	LOADCP FB_IO
+	SWAP
+	STOREI
+	DROP
 
 	FPADJ PUTPIXEL_FS
 	RET
 
+	.CPOOL
+
+INT_TO_MASK_TABLE:
+	.WORD %00001111_11111111_11111111_11111111
+	.WORD %11110000_11111111_11111111_11111111
+	.WORD %11111111_00001111_11111111_11111111
+	.WORD %11111111_11110000_11111111_11111111
+	.WORD %11111111_11111111_00001111_11111111
+	.WORD %11111111_11111111_11110000_11111111
+	.WORD %11111111_11111111_11111111_00001111
+	.WORD %11111111_11111111_11111111_11110000
+
 ; draw a line between two points
 ; parameters: x0, y0, x1, y1, color
 	.EQU DL_X0 0
diff --git a/tridoracpu/tridoracpu.srcs/vgafb.v b/tridoracpu/tridoracpu.srcs/vgafb.v
index fd42627..411e956 100644
--- a/tridoracpu/tridoracpu.srcs/vgafb.v
+++ b/tridoracpu/tridoracpu.srcs/vgafb.v
@@ -162,12 +162,10 @@ module vgafb #(VMEM_ADDR_WIDTH = 15, VMEM_DATA_WIDTH = 32) (
     reg [4:0] acc_shift_count;
     reg acc_start_shift;
     reg [VMEM_DATA_WIDTH-1:0] acc_mask_in;
-    reg [VMEM_DATA_WIDTH-1:0] acc_mask_buf;
-    reg [VMEM_DATA_WIDTH-1:0] acc_shiftmask_buf;
-    wire [VMEM_DATA_WIDTH-1:0] acc_shifter_mask = acc_shiftmask_buf;
+    wire [VMEM_DATA_WIDTH-1:0] acc_mask_out;
+    wire [VMEM_DATA_WIDTH-1:0] acc_shifter_mask;
     wire [VMEM_DATA_WIDTH-1:0] acc_shifter_out_h = acc_shifter_out[(VMEM_DATA_WIDTH*2)-1:VMEM_DATA_WIDTH];
     wire [VMEM_DATA_WIDTH-1:0] acc_shifter_out_l = acc_shifter_out[VMEM_DATA_WIDTH-1:0];
-
  `endif
 
     assign vmem_rd_en = rd_en;
@@ -178,9 +176,9 @@ module vgafb #(VMEM_ADDR_WIDTH = 15, VMEM_DATA_WIDTH = 32) (
                      (reg_sel == REG_CTL)       ? status :
 `ifdef ENABLE_FB_ACCEL
                      (reg_sel == REG_SHIFTER)   ? acc_shifter_out_h:
-                     (reg_sel == REG_SHIFTERM)  ? acc_shiftmask_buf :
+                     (reg_sel == REG_SHIFTERM)  ? acc_shifter_mask :
                      (reg_sel == REG_SHIFTERSP) ? acc_shifter_out_l :
-                     (reg_sel == REG_MASKGEN)   ? acc_mask_buf :
+                     (reg_sel == REG_MASKGEN)   ? acc_mask_out :
  `endif
                      32'hFFFFFFFF;
 
@@ -337,34 +335,27 @@ module vgafb #(VMEM_ADDR_WIDTH = 15, VMEM_DATA_WIDTH = 32) (
             acc_mask_in <= wr_data;
     end
 
-    // mask output is buffered to avoid timing problems
-    always @(posedge cpu_clk)
-    begin
-        acc_mask_buf <= {
-            {4{~|{acc_mask_in[31:28]}}},
-            {4{~|{acc_mask_in[27:24]}}},
-            {4{~|{acc_mask_in[23:20]}}},
-            {4{~|{acc_mask_in[19:16]}}},
-            {4{~|{acc_mask_in[15:12]}}},
-            {4{~|{acc_mask_in[11:8]}}},
-            {4{~|{acc_mask_in[7:4]}}},
-            {4{~|{acc_mask_in[3:0]}}}
-        };
-    end
+    assign acc_mask_out = {
+        {4{|{acc_mask_in[31:28]}}},
+        {4{|{acc_mask_in[27:24]}}},
+        {4{|{acc_mask_in[23:20]}}},
+        {4{|{acc_mask_in[19:16]}}},
+        {4{|{acc_mask_in[15:12]}}},
+        {4{|{acc_mask_in[11:8]}}},
+        {4{|{acc_mask_in[7:4]}}},
+        {4{|{acc_mask_in[3:0]}}}
+    };
 
-    always @(posedge cpu_clk)
-    begin
-        acc_shiftmask_buf = {
-            {4{~|{acc_shifter_out_h[31:28]}}},
-            {4{~|{acc_shifter_out_h[27:24]}}},
-            {4{~|{acc_shifter_out_h[23:20]}}},
-            {4{~|{acc_shifter_out_h[19:16]}}},
-            {4{~|{acc_shifter_out_h[15:12]}}},
-            {4{~|{acc_shifter_out_h[11:8]}}},
-            {4{~|{acc_shifter_out_h[7:4]}}},
-            {4{~|{acc_shifter_out_h[3:0]}}}
-        };
-    end
+    assign acc_shifter_mask = {
+        {4{|{acc_shifter_out_h[31:28]}}},
+        {4{|{acc_shifter_out_h[27:24]}}},
+        {4{|{acc_shifter_out_h[23:20]}}},
+        {4{|{acc_shifter_out_h[19:16]}}},
+        {4{|{acc_shifter_out_h[15:12]}}},
+        {4{|{acc_shifter_out_h[11:8]}}},
+        {4{|{acc_shifter_out_h[7:4]}}},
+        {4{|{acc_shifter_out_h[3:0]}}}
+    };
 `endif
 
     //
diff --git a/tridoracpu/tridoracpu.xpr b/tridoracpu/tridoracpu.xpr
index a088319..4d21f83 100644
--- a/tridoracpu/tridoracpu.xpr
+++ b/tridoracpu/tridoracpu.xpr
@@ -358,7 +358,9 @@
   <Runs Version="1" Minor="22">
     <Run Id="synth_1" Type="Ft3:Synth" SrcSet="sources_1" Part="xc7a35ticsg324-1L" ConstrsSet="constrs_1" Description="Performs optimizations which creates alternative logic technology mapping, including disabling LUT combining, forcing F7/F8/F9 to logic, increasing the threshold of shift register inference." AutoIncrementalCheckpoint="false" WriteIncrSynthDcp="false" State="current" Dir="$PRUNDIR/synth_1" IncludeInArchive="true" IsChild="false" AutoIncrementalDir="$PSRCDIR/utils_1/imports/synth_1" AutoRQSDir="$PSRCDIR/utils_1/imports/synth_1" ParallelReportGen="true">
       <Strategy Version="1" Minor="2">
-        <StratHandle Name="Flow_AlternateRoutability" Flow="Vivado Synthesis 2024"/>
+        <StratHandle Name="Flow_AlternateRoutability" Flow="Vivado Synthesis 2024">
+          <Desc>Performs optimizations which creates alternative logic technology mapping, including disabling LUT combining, forcing F7/F8/F9 to logic, increasing the threshold of shift register inference.</Desc>
+        </StratHandle>
         <Step Id="synth_design">
           <Option Id="Directive">3</Option>
           <Option Id="NoCombineLuts">1</Option>
@@ -382,7 +384,9 @@
     </Run>
     <Run Id="impl_1" Type="Ft2:EntireDesign" Part="xc7a35ticsg324-1L" ConstrsSet="constrs_1" Description="Best predicted directive for place_design." AutoIncrementalCheckpoint="false" WriteIncrSynthDcp="false" State="current" Dir="$PRUNDIR/impl_1" SynthRun="synth_1" IncludeInArchive="true" IsChild="false" GenFullBitstream="true" AutoIncrementalDir="$PSRCDIR/utils_1/imports/impl_1" LaunchOptions="-jobs 6 " AutoRQSDir="$PSRCDIR/utils_1/imports/impl_1" ParallelReportGen="true">
       <Strategy Version="1" Minor="2">
-        <StratHandle Name="Performance_Auto_1" Flow="Vivado Implementation 2024"/>
+        <StratHandle Name="Performance_Auto_1" Flow="Vivado Implementation 2024">
+          <Desc>Best predicted directive for place_design.</Desc>
+        </StratHandle>
         <Step Id="init_design"/>
         <Step Id="opt_design">
           <Option Id="Directive">0</Option>