From: Toni Wilen <twilen@winuae.net>
Date: Tue, 7 Sep 2021 16:14:33 +0000 (+0300)
Subject: Custom chipset WIP updates.
X-Git-Tag: 4900~77
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=de37a956de63e99f05ca6634ad3b686987b7366d;p=francis%2Fwinuae.git

Custom chipset WIP updates.
---

diff --git a/blitter.cpp b/blitter.cpp
index c9725631..cbb6575d 100644
--- a/blitter.cpp
+++ b/blitter.cpp
@@ -913,7 +913,7 @@ static void blit_bltset(int con)
 		blit_changed = true;
 		if (blit_warned > 0) {
 			write_log(_T("BLITTER: BLTCON0 %04x -> %04x BLTCON1 %04x -> %04x PC=%08x (%d %d)\n"), bltcon0_old, bltcon0, bltcon1_old, bltcon1, M68K_GETPC, current_hpos(), vpos);
-			blitter_dump();
+			//blitter_dump();
 			blitshifterdebug(bltcon0_old, false);
 			blit_warned--;
 			//activate_debugger();
@@ -969,7 +969,7 @@ static void blit_bltset(int con)
 	}
 
 	blit_dof = 0;
-	if ((bltcon1 & 0x80) && (currprefs.chipset_mask & CSMASK_ECS_AGNUS)) {
+	if ((bltcon1 & 0x80) && ecs_agnus) {
 		blit_dof = 1;
 		debugtest(DEBUGTEST_BLITTER, _T("ECS BLTCON1 DOFF-bit set\n"));
 		if (log_blitter & 16)
diff --git a/cfgfile.cpp b/cfgfile.cpp
index a3a7b0e2..d30f8b4c 100644
--- a/cfgfile.cpp
+++ b/cfgfile.cpp
@@ -354,6 +354,8 @@ static const TCHAR *obsolete[] = {
 	_T("compforcesettings"),
 	_T("comp_catchdetect"),
 
+	_T("hblank_glitch"),
+
 	NULL
 };
 
@@ -2529,7 +2531,6 @@ void cfgfile_save_options (struct zfile *f, struct uae_prefs *p, int type)
 	cfgfile_dwrite_bool(f, _T("z3_autoconfig"), p->cs_z3autoconfig);
 	cfgfile_dwrite_bool(f, _T("1mchipjumper"), p->cs_1mchipjumper);
 	cfgfile_dwrite_bool(f, _T("color_burst"), p->cs_color_burst);
-	cfgfile_dwrite_bool(f, _T("hblank_glitch"), p->cs_ocshblankbug);
 	cfgfile_dwrite_bool(f, _T("toshiba_gary"), p->cs_toshibagary);
 	cfgfile_dwrite_bool(f, _T("rom_is_slow"), p->cs_romisslow);
 	cfgfile_dwrite_str(f, _T("ciaa_type"), ciatype[p->cs_ciatype[0]]);
@@ -5546,7 +5547,6 @@ static int cfgfile_parse_hardware (struct uae_prefs *p, const TCHAR *option, TCH
 		|| cfgfile_yesno(option, value, _T("ics_agnus"), &p->cs_dipagnus)
 		|| cfgfile_yesno(option, value, _T("z3_autoconfig"), &p->cs_z3autoconfig)
 		|| cfgfile_yesno(option, value, _T("color_burst"), &p->cs_color_burst)
-		|| cfgfile_yesno(option, value, _T("hblank_glitch"), &p->cs_ocshblankbug)
 		|| cfgfile_yesno(option, value, _T("toshiba_gary"), &p->cs_toshibagary)
 		|| cfgfile_yesno(option, value, _T("rom_is_slow"), &p->cs_romisslow)
 		|| cfgfile_yesno(option, value, _T("1mchipjumper"), &p->cs_1mchipjumper)
@@ -8013,7 +8013,6 @@ void default_prefs (struct uae_prefs *p, bool reset, int type)
 	p->cs_ciatodbug = false;
 	p->cs_unmapped_space = 0;
 	p->cs_color_burst = false;
-	p->cs_ocshblankbug = false;
 	p->cs_ciatype[0] = 0;
 	p->cs_ciatype[1] = 0;
 
@@ -9031,7 +9030,6 @@ int built_in_chipset_prefs (struct uae_prefs *p)
 	p->cs_1mchipjumper = false;
 	p->cs_unmapped_space = 0;
 	p->cs_color_burst = false;
-	p->cs_ocshblankbug = false;
 	p->cs_romisslow = false;
 	p->cs_toshibagary = false;
 	p->cs_ciatype[0] = p->cs_ciatype[1] = 0;
diff --git a/custom.cpp b/custom.cpp
index 93adae57..6b0d9a6b 100644
--- a/custom.cpp
+++ b/custom.cpp
@@ -144,6 +144,7 @@ static bool graphicsbuffer_retry;
 static int cia_hsync;
 static bool toscr_scanline_complex_bplcon1, toscr_scanline_complex_bplcon1_off;
 static int toscr_hend;
+int display_reset;
 
 #define LOF_TOGGLES_NEEDED 3
 //#define NLACE_CNT_NEEDED 50
@@ -328,7 +329,7 @@ static int maxvpos_stored, maxhpos_stored;
 uae_u16 hsstop, hsstop_detect, hsstrt;
 static uae_u16 hbstop, hbstrt;
 static uae_u16 vsstop, vsstrt;
-static uae_u16 vbstop, vbstopm1, vbstrt;
+static uae_u16 vbstop, vbstrt;
 static uae_u16 hcenter, hcenter_v2, hcenter_v2_end;
 static uae_u16 hbstop_v, hbstrt_v, hbstop_v2, hbstrt_v2, hbstrt_v2o, hbstop_v2o;
 static int vsstrt_m, vsstop_m, vbstrt_m, vbstop_m;
@@ -1700,9 +1701,9 @@ static void update_mirrors(void)
 	ecs_agnus = (currprefs.chipset_mask & CSMASK_ECS_AGNUS) != 0;
 	ecs_denise = (currprefs.chipset_mask & CSMASK_ECS_DENISE) != 0;
 	direct_rgb = aga_mode;
-	if (currprefs.chipset_mask & CSMASK_AGA) {
+	if (aga_mode) {
 		sprite_sprctlmask = 0x01 | 0x08 | 0x10;
-	} else if (currprefs.chipset_mask & CSMASK_ECS_DENISE) {
+	} else if (ecs_denise) {
 		sprite_sprctlmask = 0x01 | 0x10;
 	} else {
 		sprite_sprctlmask = 0x01;
@@ -1935,19 +1936,20 @@ static int fetch_warn(int nr, int hpos, bool *addmodulop)
 {
 	static int warned1 = 30, warned2 = 30;
 	int add = fetchmode_bytes;
+	// fake add value must not be large enough for high word to change
 	if (cycle_line_slot[hpos] == CYCLE_STROBE) {
 		if (warned1 >= 0) {
 			write_log(_T("WARNING: BPL strobe refresh conflict, hpos %02X!\n"), hpos);
 			warned1--;
 		}
 		*addmodulop = false;
-		add = refptr_val;
+		add = refptr_val & 0x0ffe;
 	} else {
 		if (warned2 >= 0) {
 			warned2--;
 			write_log(_T("WARNING: BPL refresh conflict, hpos %02X!\n"), hpos);
 		}
-		add = refptr_val;
+		add = refptr_val & 0x0ffe;
 		*addmodulop = false;
 	}
 	return add;
@@ -4611,9 +4613,15 @@ static void reset_decisions_scanline_start(void)
 		}
 	}
 
-	if (!ecs_denise && currprefs.cs_ocshblankbug) {
-		if (vb_start_line == 2 + vblank_extraline) {
-			record_color_change2(0, 0, COLOR_CHANGE_BLANK | 1);
+	if (!ecs_denise) {
+		if (currprefs.cs_dipagnus || !ecs_agnus) {
+			if (vb_start_line == 2 + vblank_extraline) {
+				record_color_change2(0, 0, COLOR_CHANGE_BLANK | 1);
+			}
+		} else {
+			if (vb_start_line == 1 + vblank_extraline) {
+				record_color_change2(0, 0, COLOR_CHANGE_BLANK | 1);
+			}
 		}
 		if (vb_end_next_line) {
 			record_color_change2(0, 0, COLOR_CHANGE_BLANK | 0);
@@ -4682,12 +4690,17 @@ static void reset_decisions_hsync_start(void)
 	thisline_decision.fmode = fmode;
 	// 0 = vb, 1 = vb off, 3 = vb off, previous line was bitplane + vb on
 	//bool t = thisline_decision.plfleft >= 0 && (thisline_decision.vb & 1) == 0 && !vb_state && !vb_end_line;
-	thisline_decision.vb = vb_start_line > 1 + vblank_extraline ? 0 : 1;
+	if (!aga_mode && ecs_denise && exthblank) {
+		// ECS Denise + EXTHBLANK: VBLANK blanking is always disabled
+		thisline_decision.vb = 1;
+	} else {
+		thisline_decision.vb = vb_start_line > 1 + vblank_extraline ? 0 : 1;
+	}
 	// if programmed vblank
 	if (!thisline_decision.vb && (beamcon0 & 0x1000) && ecs_agnus) {
 		thisline_decision.vb |= 2;
 	}
-	if (!ecs_denise && vb_end_line && currprefs.cs_ocshblankbug) {
+	if (!ecs_denise && vb_end_line) {
 		thisline_decision.vb = 1;
 	}
 #endif
@@ -4843,26 +4856,20 @@ void compute_vsynctime(void)
 	}
 	vsynctimebase_orig = vsynctimebase;
 
-#if 0
-if (!picasso_on) {
-	updatedisplayarea();
-}
-#endif
-
-if (islinetoggle()) {
-	shpos += 0.5;
-}
-if (interlace_seen) {
-	svpos += 0.5;
-} else if (lof_current) {
-	svpos += 1.0;
-}
-if (currprefs.produce_sound > 1) {
-	double clk = svpos * shpos * fake_vblank_hz;
-	write_log(_T("SNDRATE %.1f*%.1f*%.6f=%.6f\n"), svpos, shpos, fake_vblank_hz, clk);
-	devices_update_sound(clk, syncadjust);
-}
-devices_update_sync(svpos, syncadjust);
+	if (islinetoggle()) {
+		shpos += 0.5;
+	}
+	if (interlace_seen) {
+		svpos += 0.5;
+	} else if (lof_current) {
+		svpos += 1.0;
+	}
+	if (currprefs.produce_sound > 1) {
+		double clk = svpos * shpos * fake_vblank_hz;
+		write_log(_T("SNDRATE %.1f*%.1f*%.6f=%.6f\n"), svpos, shpos, fake_vblank_hz, clk);
+		devices_update_sound(clk, syncadjust);
+	}
+	devices_update_sync(svpos, syncadjust);
 }
 
 void getsyncregisters(uae_u16 *phsstrt, uae_u16 *phsstop, uae_u16 *pvsstrt, uae_u16 *pvsstop)
@@ -4929,7 +4936,7 @@ static void checklacecount(bool lace)
 
 static void set_hcenter(void)
 {
-	if (!aga_mode && ecs_denise && (bplcon0 & 1)) {
+	if (!aga_mode && ecs_denise && (bplcon0 & 1) && (bplcon3 & 1)) {
 		if (beamcon0 & 0x0210) {
 			hcenter_v2 = (hcenter & 0xff) << CCK_SHRES_SHIFT;
 		} else {
@@ -5399,6 +5406,12 @@ static void init_hz(bool checkvposw)
 		maxhpos = htotal + 1;
 	}
 
+	// after vsync, it seems earlier possible visible line is vsync+3.
+	int vsync_startline = vsstrt + 3;
+	if (vsync_startline >= maxvpos) {
+		vsync_startline -= maxvpos;
+	}
+
 	maxhpos_display = AMIGA_WIDTH_MAX;
 	maxvpos_nom = maxvpos;
 	maxvpos_display = maxvpos;
@@ -5466,9 +5479,9 @@ static void init_hz(bool checkvposw)
 	}
 
 	if ((beamcon0 & 0x1000) && (beamcon0 & (0x0200 | 0x0010))) { // VARVBEN + VARVSYEN|VARCSYEN
-		minfirstline = vsstop;
+		minfirstline = vsync_startline;
 		if (minfirstline > maxvpos / 2) {
-			minfirstline = vsstop;
+			minfirstline = vsync_startline;
 		}
 		minfirstline++;
 		firstblankedline = vbstrt;
@@ -5498,9 +5511,6 @@ static void init_hz(bool checkvposw)
 		} else {
 			maxvpos_display_vsync = 3;
 			minfirstline -= eh / 2;
-			if (minfirstline < 8) {
-				minfirstline = 8;
-			}
 		}
 	}
 
@@ -5511,9 +5521,6 @@ static void init_hz(bool checkvposw)
 	if (minfirstline < 1) {
 		minfirstline = 1;
 	}
-	if (!(beamcon0 & 0x80) && minfirstline < 8 && !eh) {
-		minfirstline = 8;
-	}
 
 	if (minfirstline >= maxvpos) {
 		minfirstline = maxvpos - 1;
@@ -5528,39 +5535,23 @@ static void init_hz(bool checkvposw)
 	}
 
 	if (beamcon0 & (0x0200 | 0x0010)) {
-		if (maxvpos_display_vsync >= vsstop - 3) {
-			maxvpos_display_vsync = vsstop - (3 + 1);
+		if (maxvpos_display_vsync >= vsstrt) {
+			maxvpos_display_vsync = vsstrt;
 		}
 		if (maxvpos_display_vsync < 0) {
 			maxvpos_display_vsync = 0;
 		}
-		if (minfirstline <= vsstop) {
-			minfirstline = vsstop + 1;
+		if (minfirstline <= vsync_startline) {
+			minfirstline = vsync_startline;
 		}
 	}
 
-	vbstopm1 = vbstop - 1;
-	if (vbstopm1 < 0) {
-		vbstopm1 += maxvpos;
-	}
-
 	if (beamcon0 & 0x80) {
 		vblank_hz_nom = vblank_hz = clk / (maxvpos * maxhpos);
 		vblank_hz_shf = vblank_hz;
 		vblank_hz_lof = clk / ((maxvpos + 1) * maxhpos);
 		vblank_hz_lace = clk / ((maxvpos + 0.5) * maxhpos);
 
-		if (beamcon0 & (0x0200 | 0x0010)) {
-			minfirstline = vsstop;
-			if (minfirstline > vtotal / 2) {
-				minfirstline = 1;
-			}
-			firstblankedline = vsstrt;
-			if (firstblankedline < vtotal / 2) {
-				firstblankedline = maxvpos + 1;
-			}
-		}
-
 		maxvpos_nom = maxvpos;
 		maxvpos_display = maxvpos;
 		equ_vblank_endline = -1;
@@ -5624,6 +5615,7 @@ static void init_hz(bool checkvposw)
 
 	compute_framesync();
 	devices_syncchange();
+	display_reset = 2;
 
 #ifdef PICASSO96
 	init_hz_p96(0);
@@ -5658,8 +5650,14 @@ static void calcdiw(void)
 
 	// ECS Agnus/AGA: DIWHIGH vertical high bits.
 	if (diwhigh_written && ecs_agnus) {
-		vstrt |= (diwhigh & 7) << 8;
-		vstop |= ((diwhigh >> 8) & 7) << 8;
+		if (aga_mode) {
+			vstrt |= (diwhigh & 7) << 8;
+			vstop |= ((diwhigh >> 8) & 7) << 8;
+		} else {
+			// ECS Agnus has undocumented V11!
+			vstrt |= (diwhigh & 15) << 8;
+			vstop |= ((diwhigh >> 8) & 15) << 8;
+		}
 	} else {
 		if ((vstop & 0x80) == 0)
 			vstop |= 0x100;
@@ -5858,8 +5856,6 @@ static bool hsyncdelay(void)
 
 #define CPU_ACCURATE (currprefs.cpu_model < 68020 || (currprefs.cpu_model == 68020 && currprefs.cpu_memory_cycle_exact))
 
-#define VPOS_INC_DELAY (CPU_ACCURATE ? 1 : 0)
-
 static void vb_check(void)
 {
 	// A1000 Agnus VBSTRT=first line, OCS and later: VBSTRT=last line
@@ -5880,6 +5876,18 @@ static void vb_check(void)
 	}
 }
 
+static void vhpos_adj(uae_u16 *hpp, uae_u16 *vpp)
+{
+	uae_u16 hp = *hpp;
+	uae_u16 vp = *vpp;
+	if (hp == 0) {
+		// HP=0: VP = previous line.
+		vp = vpos_prev;
+	}
+	*hpp = hp;
+	*vpp = vp;
+}
+
 static uae_u16 VPOSR(void)
 {
 	unsigned int csbit = 0;
@@ -5893,12 +5901,8 @@ static uae_u16 VPOSR(void)
 			lof = lof ? 0 : 1;
 		}
 	}
-	if (hp >= maxhpos + VPOS_INC_DELAY) {
-		vp++;
-		if (vp >= maxvpos + lof_store) {
-			vp = 0;
-		}
-	}
+	vhpos_adj(&hp, &vp);
+
 	vp = (vp >> 8) & 7;
 
 	if (currprefs.cs_agnusrev >= 0) {
@@ -6003,26 +6007,17 @@ static void VHPOSW(uae_u16 v)
 #endif
 }
 
-static uae_u16 VHPOSR (void)
+static uae_u16 VHPOSR(void)
 {
 	static uae_u16 oldhp;
 	uae_u16 vp = GETVPOS();
 	uae_u16 hp = GETHPOS();
 
-	if (hp >= maxhpos) {
-		hp -= maxhpos;
-		// vpos increases when hp==1, not when hp==0
-		if (hp >= VPOS_INC_DELAY) {
-			vp++;
-			if (vp >= maxvpos + lof_store) {
-				vp = 0;
-			}
-		}
-	}
+	vhpos_adj(&hp, &vp);
 
 	vp <<= 8;
 
-	if (hsyncdelay ()) {
+	if (hsyncdelay()) {
 		// fake continuously changing hpos in fastest possible modes
 		hp = oldhp % maxhpos;
 		oldhp++;
@@ -6471,7 +6466,7 @@ bool INTREQ_0(uae_u16 v)
 		serial_rbf_clear();
 	}
 
-	if ((v & 0x8000) && old != v) {
+	if (old != v) {
 		doint_delay();
 	}
 	return true;
@@ -6501,9 +6496,9 @@ static void ADKCON(int hpos, uae_u16 v)
 static void check_harddis(void)
 {
 	// VARBEAMEN, HARDDIS, SHRES, UHRES
-	harddis_h = ecs_agnus && ((new_beamcon0 & 0x80) || (new_beamcon0 & 0x4000) || (bplcon0 & 0x40) || (bplcon0 & 0x80));
+	harddis_h = ecs_agnus && ((new_beamcon0 & 0x0080) || (new_beamcon0 & 0x4000) || (bplcon0 & 0x0040) || (bplcon0 & 0x0080));
 	// VARBEAMEN, VARVBEN, HARDDIS
-	harddis_v = ecs_agnus && ((new_beamcon0 & 0x80) || (new_beamcon0 & 0x1000) || (new_beamcon0 & 0x4000));
+	harddis_v = ecs_agnus && ((new_beamcon0 & 0x0080) || (new_beamcon0 & 0x1000) || (new_beamcon0 & 0x4000));
 }
 
 static void BEAMCON0(int hpos, uae_u16 v)
@@ -6935,7 +6930,7 @@ static void DIWHIGH(int hpos, uae_u16 v)
 		return;
 	}
 	if (!aga_mode) {
-		v &= ~(0x0008 | 0x0010 | 0x1000 | 0x0800);
+		v &= ~(0x0010 | 0x1000);
 	}
 	v &= ~(0x8000 | 0x4000 | 0x0080 | 0x0040);
 	if (diwhigh_written && diwhigh == v) {
@@ -8224,6 +8219,9 @@ static void do_copper_fetch(int hpos, uae_u8 id)
 			alloc_cycle(hpos, CYCLE_COPPER);
 			cop_state.ip += 2;
 
+#ifdef DEBUGGER
+			uaecptr debugip = cop_state.ip;
+#endif
 			cop_state.ignore_next = 0;
 			if (cop_state.ir[1] & 1) {
 				cop_state.state = COP_skip_in2;
@@ -8234,6 +8232,8 @@ static void do_copper_fetch(int hpos, uae_u8 id)
 			cop_state.vcmp = (cop_state.ir[0] & (cop_state.ir[1] | 0x8000)) >> 8;
 			cop_state.hcmp = (cop_state.ir[0] & cop_state.ir[1] & 0xFE);
 
+			record_copper(debugip - 4, debugip, cop_state.ir[0], cop_state.ir[1], hpos, vpos);
+
 		} else {
 			// MOVE
 			uae_u16 reg = cop_state.ir[0] & 0x1FE;
@@ -9031,6 +9031,15 @@ static void maybe_process_pull_audio(void)
 	audio_finish_pull();
 }
 
+static bool crender_screen(int monid, int mode, bool immediate)
+{
+	bool v = render_screen(monid, mode, immediate);
+	if (display_reset > 0) {
+		display_reset--;
+	}
+	return v;
+}
+
 // moving average algorithm
 #define MAVG_MAX_SIZE 128
 struct mavg_data
@@ -9092,7 +9101,7 @@ static bool framewait(void)
 		curr_time = read_processor_time();
 		vsyncwaittime = vsyncmaxtime = curr_time + vsynctimebase;
 		if (!frame_rendered && !ad->picasso_on) {
-			frame_rendered = render_screen(0, 1, false);
+			frame_rendered = crender_screen(0, 1, false);
 		}
 
 		start = read_processor_time();
@@ -9164,7 +9173,7 @@ static bool framewait(void)
 	if (currprefs.m68k_speed < 0 && !cpu_sleepmode && !currprefs.cpu_memory_cycle_exact) {
 
 		if (!frame_rendered && !ad->picasso_on)
-			frame_rendered = render_screen(0, 1, false);
+			frame_rendered = crender_screen(0, 1, false);
 
 		if (currprefs.m68k_speed_throttle) {
 			// this delay can safely overshoot frame time by 1-2 ms, following code will compensate for it.
@@ -9210,7 +9219,7 @@ static bool framewait(void)
 
 		start = read_processor_time();
 		if (!frame_rendered && !ad->picasso_on) {
-			frame_rendered = render_screen(0, 1, false);
+			frame_rendered = crender_screen(0, 1, false);
 			t = read_processor_time() - start;
 		}
 		if (!currprefs.cpu_thread) {
@@ -9316,7 +9325,8 @@ static void fpscounter(bool frameok)
 }
 
 // vsync functions that are not hardware timing related
-// called when display is blanked, not necessarily last line but line 0 or later.
+// called when vsync starts which is not necessarily last line
+// it can line 0 or even later.
 static void vsync_handler_render(void)
 {
 	struct amigadisplay *ad = &adisplays[0];
@@ -9356,15 +9366,6 @@ static void vsync_handler_render(void)
 	cpu_stopped_lines = 0;
 #endif
 
-	if (bogusframe > 0) {
-		bogusframe--;
-	}
-
-	config_check_vsync();
-	if (timehack_alive > 0) {
-		timehack_alive--;
-	}
-
 #ifdef PICASSO96
 	if (isvsync_rtg() >= 0) {
 		rtg_vsync();
@@ -9384,7 +9385,7 @@ static void vsync_handler_render(void)
 	
 	if (!ad->picasso_on) {
 		if (!frame_rendered && vblank_hz_state) {
-			frame_rendered = render_screen(0, 1, false);
+			frame_rendered = crender_screen(0, 1, false);
 		}
 		if (frame_rendered && !frame_shown) {
 			frame_shown = show_screen_maybe(0, isvsync_chipset () >= 0);
@@ -9396,15 +9397,17 @@ static void vsync_handler_render(void)
 	bool waspaused = false;
 	while (handle_events()) {
 		if (!waspaused) {
-			render_screen(0, 1, true);
-			show_screen(0, 0);
+			if (crender_screen(0, 1, true)) {
+				show_screen(0, 0);
+			}
 			waspaused = true;
 		}
 		// we are paused, do all config checks but don't do any emulation
 		if (vsync_handle_check()) {
 			redraw_frame();
-			render_screen(0, 1, true);
-			show_screen(0, 0);
+			if (crender_screen(0, 1, true)) {
+				show_screen(0, 0);
+			}
 		}
 		config_check_vsync();
 	}
@@ -9429,7 +9432,6 @@ static void vsync_handler_render(void)
 
 	nextline_how = nln_normal;
 
-	vsync_handle_check();
 	//checklacecount (bplcon0_interlace_seen || lof_lace);
 }
 
@@ -9447,15 +9449,12 @@ static void vsync_display_render(void)
 static void vsync_check_vsyncmode(void)
 {
 	if (varsync_changed == 1) {
-		// render screen (minus extra lines) because mode is going to change and we don't want black screen flash
-		vsync_display_render();
 		init_hz_normal();
 	} else if (vpos_count > 0 && abs(vpos_count - vpos_count_diff) > 1 && vposw_change < 4) {
-		vsync_display_render();
 		init_hz_vposw();
 	} else if (interlace_changed || changed_chipset_refresh() || lof_changed) {
-		vsync_display_render();
 		compute_framesync();
+		display_reset = 2;
 	}
 	if (varsync_changed > 0) {
 		varsync_changed--;
@@ -9569,14 +9568,26 @@ static void vsync_handler_post(void)
 			varsync_changed = 2;
 		}
 	}
+
 	vsync_check_vsyncmode();
 
+	if (bogusframe > 0) {
+		bogusframe--;
+	}
+
+	config_check_vsync();
+	if (timehack_alive > 0) {
+		timehack_alive--;
+	}
+
 	lof_changed = 0;
 	vposw_change = 0;
 	bplcon0_interlace_seen = false;
 
 	COPJMP(1, 1);
 
+	vsync_handle_check();
+
 	init_hardware_frame();
 
 	vsync_cycles = get_cycles();
@@ -9882,7 +9893,7 @@ static bool is_custom_vsync (void)
 static bool do_render_slice(int mode, int slicecnt, int lastline)
 {
 	draw_lines(lastline, slicecnt);
-	render_screen(0, mode, true);
+	crender_screen(0, mode, true);
 	return true;
 }
 
@@ -10057,7 +10068,7 @@ static void hsync_handlerh(bool onvsync)
 	hpos_hsync_extra = 0;
 	estimate_last_fetch_cycle(hpos);
 
-	if (vb_end_line && !ecs_denise && currprefs.cs_ocshblankbug) {
+	if (vb_end_line && !ecs_denise) {
 		record_color_change2(hpos, 0, COLOR_CHANGE_BLANK | 1);
 	}
 
@@ -10937,7 +10948,8 @@ static void hsync_handler_post (bool onvsync)
 	}
 	// vblank interrupt = next line after VBSTRT
 	if (vb_start_line == 1) {
-		send_interrupt(5, 1 * CYCLE_UNIT);
+		// first refresh (strobe) slot triggers vblank interrupt
+		send_interrupt(5, REFRESH_FIRST_HPOS * CYCLE_UNIT);
 	}
 	// lastline - 1?
 	if (vpos + 1 == maxvpos + lof_store || vpos + 1 == maxvpos + lof_store + 1) {
@@ -10984,7 +10996,11 @@ static void hsync_handler_post (bool onvsync)
 				vb_start_line = 1;
 				vb_state = true;
 			}
-			if (vbstopm1 == vpos) {
+			int vbs = vbstop - 1;
+			if (vbs < 0) {
+				vbs += maxvpos;
+			}
+			if (vbs == vpos) {
 				vbstop_m = vpos;
 				vb_end_line = true;
 				vb_state = false;
@@ -11038,6 +11054,7 @@ static void hsync_handler_post (bool onvsync)
 			vs_state_hw = false;
 		}
 	}
+
 	if (new_beamcon0 & (0x0200 | 0x0010)) {
 		vs_state_on = vs_state;
 	} else {
@@ -11256,7 +11273,7 @@ static void hsync_handler_post (bool onvsync)
 		vsync_rendered = true;
 		vsync_handle_redraw (lof_store, lof_changed, bplcon0, bplcon3);
 		if (vblank_hz_state) {
-			frame_rendered = render_screen(1, true);
+			frame_rendered = crender_screen(1, true);
 		}
 		end = read_processor_time ();
 		frameskiptime += end - start;
@@ -11402,8 +11419,10 @@ void custom_reset(bool hardreset, bool keyboardreset)
 	hbstop_v2 = 0;
 	hcenter_v2 = 0;
 	set_hcenter();
+	display_reset = 1;
 
 	if (!savestate_state) {
+		refptr_val = 0;
 		cia_hsync = 0;
 		extra_cycle = 0;
 		hsync_counter = 0;
@@ -12982,7 +13001,6 @@ void check_prefs_changed_custom (void)
 	currprefs.cs_z3autoconfig = changed_prefs.cs_z3autoconfig;
 	currprefs.cs_bytecustomwritebug = changed_prefs.cs_bytecustomwritebug;
 	currprefs.cs_color_burst = changed_prefs.cs_color_burst;
-	currprefs.cs_ocshblankbug = changed_prefs.cs_ocshblankbug;
 	currprefs.cs_romisslow = changed_prefs.cs_romisslow;
 	currprefs.cs_toshibagary = changed_prefs.cs_toshibagary;
 	currprefs.cs_unmapped_space = changed_prefs.cs_unmapped_space;
diff --git a/drawing.cpp b/drawing.cpp
index d79129d5..37ee9dc7 100644
--- a/drawing.cpp
+++ b/drawing.cpp
@@ -497,15 +497,23 @@ static void set_vblanking_limits(void)
 		vblank_bottom_stop = visible_bottom_stop;
 	}
 
-	bool hardwired = false;
+	bool hardwired = true;
 	if (ecs_agnus) {
 		hardwired = (new_beamcon0 & 0x1000) == 0;
 	}
 	if (hardwired) {
 		int vbstrt = vblank_firstline_hw;
+		if (!ecs_denise) {
+			vbstrt--;
+		}
 		int vbstop = maxvpos + lof_store;
-		if (currprefs.cs_dipagnus) {
+		if (!ecs_denise && !ecs_agnus) {
 			vbstop++;
+		} else if (ecs_agnus && !ecs_denise) {
+			// hide hblank bug by faking vblank start 1 line earlier
+			if (currprefs.gfx_overscanmode < OVERSCANMODE_BROADCAST) {
+				vbstop--;
+			}
 		}
 		if (currprefs.gfx_overscanmode < OVERSCANMODE_OVERSCAN) {
 			int mult = (OVERSCANMODE_OVERSCAN - currprefs.gfx_overscanmode) * 5;
@@ -3210,6 +3218,7 @@ static void do_color_changes(line_draw_func worker_border, line_draw_func worker
 	int lastpos = visible_left_border;
 	int endpos = visible_left_border + vidinfo->drawbuffer.inwidth;
 
+	extborder = false; // reset here because it always have start and end in same scanline
 	for (i = dip_for_drawing->first_color_change; i <= dip_for_drawing->last_color_change; i++) {
 		int regno = curr_color_changes[i].regno;
 		uae_u32 value = curr_color_changes[i].value;
@@ -4288,7 +4297,7 @@ void draw_lines(int end, int section)
 	int section_color_cnt = 4;
 
 	vidinfo->outbuffer = vb;
-	if (!lockscr(vb, false, vb->last_drawn_line ? false : true))
+	if (!lockscr(vb, false, vb->last_drawn_line ? false : true, display_reset > 0))
 		return;
 
 	set_vblanking_limits();
@@ -4435,7 +4444,7 @@ static void finish_drawing_frame(bool drawlines)
 		return;
 	}
 
-	if (!lockscr(vb, false, true)) {
+	if (!lockscr(vb, false, true, display_reset > 0)) {
 		notice_screen_contents_lost(monid);
 		return;
 	}
@@ -4455,7 +4464,7 @@ static void finish_drawing_frame(bool drawlines)
 		bool locked = true;
 		bool multimon = currprefs.monitoremu_mon != 0;
 		if (multimon) {
-			locked = lockscr(out, false, true);
+			locked = lockscr(out, false, true, display_reset > 0);
 			outvi->xchange = vidinfo->xchange;
 			outvi->ychange = vidinfo->ychange;
 		} else {
@@ -4530,7 +4539,7 @@ static void finish_drawing_frame(bool drawlines)
 		vidinfo->drawbuffer.tempbufferinuse = true;
 	}
 
-	unlockscr(vb, -1, -1);
+	unlockscr(vb, display_reset ? -2 : -1, -1);
 }
 
 void check_prefs_picasso(void)
@@ -4881,6 +4890,7 @@ void reset_drawing(void)
 	exthblank = false;
 	exthblanken = false;
 	extborder = false;
+	display_reset = 1;
 
 	lores_reset ();
 
diff --git a/include/custom.h b/include/custom.h
index 15dbd371..608daebe 100644
--- a/include/custom.h
+++ b/include/custom.h
@@ -136,6 +136,7 @@ extern float hblank_hz;
 extern int vblank_skip, doublescan;
 extern int programmedmode;
 extern int vblank_firstline_hw;
+extern int display_reset;
 
 #define DMA_AUD0      0x0001
 #define DMA_AUD1      0x0002
diff --git a/include/options.h b/include/options.h
index fc366702..9f8dcbbf 100644
--- a/include/options.h
+++ b/include/options.h
@@ -691,7 +691,6 @@ struct uae_prefs {
 	int cs_hacks;
 	int cs_ciatype[2];
 	int cs_kbhandshake;
-	bool cs_ocshblankbug;
 
 	struct boardromconfig expansionboard[MAX_EXPANSION_BOARDS];
 
diff --git a/include/xwin.h b/include/xwin.h
index 0775f0c0..70f88c00 100644
--- a/include/xwin.h
+++ b/include/xwin.h
@@ -53,7 +53,7 @@ extern bool render_screen(int monid, int, bool);
 extern void show_screen(int monid, int mode);
 extern bool show_screen_maybe(int monid, bool);
 
-extern int lockscr(struct vidbuffer*, bool, bool);
+extern int lockscr(struct vidbuffer*, bool, bool, bool);
 extern void unlockscr(struct vidbuffer*, int, int);
 extern bool target_graphics_buffer_update(int monid);
 extern float target_adjust_vblank_hz(int monid, float);
diff --git a/od-win32/direct3d.cpp b/od-win32/direct3d.cpp
index 83e4c7ce..870bb4f3 100644
--- a/od-win32/direct3d.cpp
+++ b/od-win32/direct3d.cpp
@@ -157,7 +157,7 @@ struct d3dstruct
 	IDirect3DDevice9 *d3ddev;
 	IDirect3DDevice9Ex *d3ddevex;
 	D3DSURFACE_DESC dsdbb;
-	LPDIRECT3DTEXTURE9 texture, sltexture, ledtexture, blanktexture;
+	LPDIRECT3DTEXTURE9 texture1, texture2, usetexture, sltexture, ledtexture, blanktexture;
 	LPDIRECT3DTEXTURE9 mask2texture, mask2textureleds[9], mask2textureled_power_dim;
 	int mask2textureledoffsets[9 * 2];
 	IDirect3DQuery9 *query;
@@ -181,6 +181,7 @@ struct d3dstruct
 
 	volatile bool fakemode;
 	uae_u8 *fakebitmap;
+	int fakelock;
 	uae_thread_id fakemodetid;
 
 	D3DXMATRIXA16 m_matProj, m_matProj2, m_matProj_out;
@@ -1289,8 +1290,9 @@ static int createamigatexture (struct d3dstruct *d3d, int w, int h)
 {
 	HRESULT hr;
 
-	d3d->texture = createtext (d3d, w, h, d3d->tformat);
-	if (!d3d->texture)
+	d3d->texture1 = createtext(d3d, w, h, d3d->tformat);
+	d3d->texture2 = createtext(d3d, w, h, d3d->tformat);
+	if (!d3d->texture1 || !d3d->texture2)
 		return 0;
 	write_log (_T("%s: %d*%d main texture, depth %d\n"), D3DHEAD, w, h, d3d->t_depth);
 	if (d3d->psActive) {
@@ -2359,9 +2361,13 @@ static void settransform2 (struct d3dstruct *d3d, struct shaderdata *s)
 
 static void freetextures (struct d3dstruct *d3d)
 {
-	if (d3d->texture) {
-		d3d->texture->Release ();
-		d3d->texture = NULL;
+	if (d3d->texture2) {
+		d3d->texture2->Release();
+		d3d->texture2 = NULL;
+	}
+	if (d3d->texture1) {
+		d3d->texture1->Release();
+		d3d->texture1 = NULL;
 	}
 	for (int i = 0; i < MAX_SHADERS; i++) {
 		struct shaderdata *s = &d3d->shaders[i];
@@ -3424,10 +3430,10 @@ static void D3D_render2(struct d3dstruct *d3d, int mode)
 {
 	struct AmigaMonitor *mon = &AMonitors[d3d - d3ddata];
 	HRESULT hr;
-	LPDIRECT3DTEXTURE9 srctex = d3d->texture;
+	LPDIRECT3DTEXTURE9 srctex = d3d->usetexture;
 	UINT uPasses, uPass;
 
-	if (!isd3d (d3d) || !d3d->texture)
+	if (!isd3d (d3d) || !srctex)
 		return;
 
 	bool normalrender = mode < 0 || (mode & 1);
@@ -3776,7 +3782,7 @@ static void xD3D_flushtexture(int monid, int miny, int maxy)
 {
 	struct d3dstruct *d3d = &d3ddata[monid];
 
-	if (d3d->fakemode || d3d->fulllocked || !d3d->texture || d3d->renderdisabled)
+	if (d3d->fakemode || d3d->fulllocked || !d3d->texture1 || d3d->renderdisabled)
 		return;
 	if (miny >= 0 && maxy >= 0) {
 		RECT r;
@@ -3786,7 +3792,7 @@ static void xD3D_flushtexture(int monid, int miny, int maxy)
 		r.top = miny <= 0 ? 0 : miny;
 		r.bottom = maxy <= d3d->tin_h ? maxy : d3d->tin_h;
 		if (r.top <= r.bottom) {
-			HRESULT hr = d3d->texture->AddDirtyRect (&r);
+			HRESULT hr = d3d->texture1->AddDirtyRect (&r);
 			if (FAILED (hr))
 				write_log (_T("%s: AddDirtyRect(): %s\n"), D3DHEAD, D3D_ErrorString (hr));
 			//write_log (_T("%d %d\n"), r.top, r.bottom);
@@ -3799,13 +3805,22 @@ static void xD3D_unlocktexture(int monid, int y_start, int y_end)
 	struct d3dstruct *d3d = &d3ddata[monid];
 	HRESULT hr;
 
-	if (!isd3d(d3d) || !d3d->texture)
+	if (!isd3d(d3d) || !d3d->texture1)
+		return;
+
+	if (d3d->fakelock) {
+		d3d->fakelock--;
 		return;
+	}
 
 	if (d3d->locked) {
+		LPDIRECT3DTEXTURE9 tex = d3d->texture1;
+		if (d3d->locked == 2) {
+			tex = d3d->texture2;
+		}
 		if (currprefs.leds_on_screen & (STATUSLINE_CHIPSET | STATUSLINE_RTG))
 			updateleds(d3d);
-		hr = d3d->texture->UnlockRect(0);
+		hr = tex->UnlockRect(0);
 		if (y_start >= 0)
 			xD3D_flushtexture(monid, y_start, y_end);
 	}
@@ -3813,7 +3828,7 @@ static void xD3D_unlocktexture(int monid, int y_start, int y_end)
 	d3d->fulllocked = 0;
 }
 
-static uae_u8 *xD3D_locktexture (int monid, int *pitch, int *height, bool fullupdate)
+static uae_u8 *xD3D_locktexture (int monid, int *pitch, int *height, int fullupdate)
 {
 	struct d3dstruct *d3d = &d3ddata[monid];
 	D3DLOCKED_RECT lock;
@@ -3824,10 +3839,28 @@ static uae_u8 *xD3D_locktexture (int monid, int *pitch, int *height, bool fullup
 		return d3d->fakebitmap;
 	}
 
+	if (fullupdate < 0) {
+		if (d3d->usetexture == d3d->texture1) {
+			LPDIRECT3DTEXTURE9 tex1 = d3d->texture1;
+			LPDIRECT3DTEXTURE9 tex2 = d3d->texture2;
+			IDirect3DSurface9* s1, * s2;
+			if (SUCCEEDED(tex1->GetSurfaceLevel(0, &s1))) {
+				if (SUCCEEDED(tex2->GetSurfaceLevel(0, &s2))) {
+					HRESULT hr = d3d->d3ddev->StretchRect(s1, NULL, s2, NULL, D3DTEXF_NONE);
+					s2->Release();
+					d3d->usetexture = tex2;
+				}
+				s1->Release();
+			}
+		}
+	} else {
+		d3d->usetexture = d3d->texture1;
+	}
+
 	if (D3D_needreset (d3d) > 0) {
 		return NULL;
 	}
-	if (!isd3d (d3d) || !d3d->texture)
+	if (!isd3d (d3d))
 		return NULL;
 
 	if (d3d->locked) {
@@ -3835,9 +3868,15 @@ static uae_u8 *xD3D_locktexture (int monid, int *pitch, int *height, bool fullup
 		return NULL;
 	}
 
+	if (!d3d->texture1) {
+		*pitch = 0;
+		d3d->fakelock++;
+		return d3d->fakebitmap;
+	}
+
 	lock.pBits = NULL;
 	lock.Pitch = 0;
-	hr = d3d->texture->LockRect (0, &lock, NULL, fullupdate ? D3DLOCK_DISCARD : D3DLOCK_NO_DIRTY_UPDATE);
+	hr = d3d->texture1->LockRect (0, &lock, NULL, fullupdate > 0 ? D3DLOCK_DISCARD : D3DLOCK_NO_DIRTY_UPDATE);
 	if (FAILED (hr)) {
 		write_log (_T("%s: LockRect failed: %s\n"), D3DHEAD, D3D_ErrorString (hr));
 		return NULL;
@@ -3848,7 +3887,7 @@ static uae_u8 *xD3D_locktexture (int monid, int *pitch, int *height, bool fullup
 		D3D_unlocktexture(monid, -1, -1);
 		return NULL;
 	}
-	d3d->fulllocked = fullupdate;
+	d3d->fulllocked = fullupdate > 0;
 	*pitch = lock.Pitch;
 	if (height)
 		*height = d3d->tin_h;
@@ -3886,7 +3925,7 @@ static bool xD3D_renderframe(int monid, int mode, bool immediate)
 	if (d3d->fakemode)
 		return true;
 
-	if (!isd3d (d3d) || !d3d->texture)
+	if (!isd3d (d3d) || !d3d->texture1 || !d3d->texture2)
 		return false;
 
 	if (d3d->filenotificationhandle != NULL) {
@@ -4071,7 +4110,7 @@ LPDIRECT3DSURFACE9 D3D_capture(int monid, int *w, int *h, int *bits, bool render
 		}
 		ret = d3d->screenshotsurface;
 	} else {
-		hr = d3d->texture->GetSurfaceLevel(0, &ret);
+		hr = d3d->texture1->GetSurfaceLevel(0, &ret);
 		if (FAILED(hr)) {
 			write_log(_T("%s: D3D_capture() GetSurfaceLevel() failed: %s\n"), D3DHEAD, D3D_ErrorString(hr));
 			return NULL;
diff --git a/od-win32/direct3d.h b/od-win32/direct3d.h
index fd420e84..e7c9d483 100644
--- a/od-win32/direct3d.h
+++ b/od-win32/direct3d.h
@@ -14,7 +14,7 @@ extern void(*D3D_refresh)(int);
 extern bool(*D3D_renderframe)(int, int,bool);
 extern void(*D3D_showframe)(int);
 extern void(*D3D_showframe_special)(int, int);
-extern uae_u8* (*D3D_locktexture)(int, int*, int*, bool);
+extern uae_u8* (*D3D_locktexture)(int, int*, int*, int);
 extern void(*D3D_unlocktexture)(int, int, int);
 extern void(*D3D_flushtexture)(int, int miny, int maxy);
 extern void(*D3D_guimode)(int, int);
diff --git a/od-win32/direct3d11.cpp b/od-win32/direct3d11.cpp
index e53a7719..342200b3 100644
--- a/od-win32/direct3d11.cpp
+++ b/od-win32/direct3d11.cpp
@@ -47,7 +47,7 @@ void(*D3D_refresh)(int);
 bool(*D3D_renderframe)(int, int,bool);
 void(*D3D_showframe)(int);
 void(*D3D_showframe_special)(int, int);
-uae_u8* (*D3D_locktexture)(int, int*, int*, bool);
+uae_u8* (*D3D_locktexture)(int, int*, int*, int);
 void (*D3D_unlocktexture)(int, int, int);
 void (*D3D_flushtexture)(int, int miny, int maxy);
 void (*D3D_guimode)(int, int);
@@ -1998,7 +1998,7 @@ static bool CreateTexture(struct d3d11struct *d3d)
 		return false;
 	}
 
-	ID3D11Texture2D* pSurface;
+	ID3D11Texture2D *pSurface;
 	hr = d3d->m_swapChain->GetBuffer(0, __uuidof(ID3D11Texture2D), reinterpret_cast< void** >(&pSurface));
 	if (SUCCEEDED(hr)) {
 		memset(&desc, 0, sizeof desc);
@@ -4788,7 +4788,7 @@ static bool xD3D11_alloctexture(int monid, int w, int h)
 	return true;
 }
 
-static uae_u8 *xD3D11_locktexture(int monid, int *pitch, int *height, bool fullupdate)
+static uae_u8 *xD3D11_locktexture(int monid, int *pitch, int *height, int fullupdate)
 {
 	struct d3d11struct *d3d = &d3d11data[monid];
 
@@ -4822,6 +4822,10 @@ static void xD3D11_unlocktexture(int monid, int y_start, int y_end)
 
 	d3d->m_deviceContext->Unmap(d3d->texture2dstaging, 0);
 
+	if (y_start < -1 || y_end < -1) {
+		return;
+	}
+
 	bool rtg = WIN32GFX_IsPicassoScreen(mon);
 	if (((currprefs.leds_on_screen & STATUSLINE_CHIPSET) && !rtg) || ((currprefs.leds_on_screen & STATUSLINE_RTG) && rtg)) {
 		d3d->osd.enabled = true;
diff --git a/od-win32/resources/resource.h b/od-win32/resources/resource.h
index dcb81a24..7d172300 100644
--- a/od-win32/resources/resource.h
+++ b/od-win32/resources/resource.h
@@ -1149,7 +1149,6 @@
 #define IDC_DBG_MEM                     1756
 #define IDC_CS_COMPOSITECOLOR           1756
 #define IDC_DBG_DASM                    1757
-#define IDC_CS_OCSHBLANKBUG             1757
 #define IDC_DBG_MEMDOWNFAST             1758
 #define IDC_CS_TOSHIBAGARY              1758
 #define IDC_DBG_MEMTOPC                 1759
diff --git a/od-win32/resources/winuae.rc b/od-win32/resources/winuae.rc
index 426dfdbc..b0118c08 100644
--- a/od-win32/resources/winuae.rc
+++ b/od-win32/resources/winuae.rc
@@ -851,7 +851,6 @@ BEGIN
     CONTROL         "KS ROM has Chip RAM speed",IDC_CS_ROMISSLOW,"Button",BS_AUTOCHECKBOX | WS_TABSTOP,127,197,125,12
     CONTROL         "CIA 391078-01 [] CIA revision that can't read IO pin status in output mode",IDC_CS_CIA,
                     "Button",BS_AUTOCHECKBOX | WS_TABSTOP,264,197,125,12
-    CONTROL         "OCS H-Blank glitch",IDC_CS_OCSHBLANKBUG,"Button",BS_AUTOCHECKBOX | WS_TABSTOP,264,184,125,12
 END
 
 IDD_AVIOUTPUT DIALOGEX 0, 0, 396, 316
diff --git a/od-win32/win32_scaler.cpp b/od-win32/win32_scaler.cpp
index 7acc7ac7..e87b1426 100644
--- a/od-win32/win32_scaler.cpp
+++ b/od-win32/win32_scaler.cpp
@@ -1052,7 +1052,7 @@ void S2X_render(int monid, int y_start, int y_end)
 	if (d3d) {
 		if (D3D_restore)
 			D3D_restore(monid, true);
-		surfstart = D3D_locktexture(monid, &pitch, &surf_height, y_start < 0);
+		surfstart = D3D_locktexture(monid, &pitch, &surf_height, y_start < -1 ? -1 : (y_start < 0 ? 1 : 0));
 		if (surfstart == NULL)
 			return;
 	} else {
diff --git a/od-win32/win32gfx.cpp b/od-win32/win32gfx.cpp
index 3963c960..95a6315e 100644
--- a/od-win32/win32gfx.cpp
+++ b/od-win32/win32gfx.cpp
@@ -1601,7 +1601,7 @@ void unlockscr3d(struct vidbuffer *vb)
 	}
 }
 
-int lockscr(struct vidbuffer *vb, bool fullupdate, bool first)
+int lockscr(struct vidbuffer *vb, bool fullupdate, bool first, bool skip)
 {
 	struct AmigaMonitor *mon = &AMonitors[vb->monitor_id];
 	int ret = 0;
@@ -1620,7 +1620,7 @@ int lockscr(struct vidbuffer *vb, bool fullupdate, bool first)
 			ret = 1;
 		} else {
 			ret = 0;
-			vb->bufmem = D3D_locktexture(vb->monitor_id, &vb->rowbytes, NULL, fullupdate);
+			vb->bufmem = D3D_locktexture(vb->monitor_id, &vb->rowbytes, NULL, skip ? -1 : (fullupdate ? 1 : 0));
 			if (vb->bufmem) {
 				if (first)
 					init_row_map();
@@ -1661,7 +1661,7 @@ void flush_clear_screen (struct vidbuffer *vb)
 {
 	if (!vb)
 		return;
-	if (lockscr(vb, true, true)) {
+	if (lockscr(vb, true, true, false)) {
 		int y;
 		for (y = 0; y < vb->height_allocated; y++) {
 			memset(vb->bufmem + y * vb->rowbytes, 0, vb->width_allocated * vb->pixbytes);
diff --git a/od-win32/win32gui.cpp b/od-win32/win32gui.cpp
index c3f2daed..7f878c95 100644
--- a/od-win32/win32gui.cpp
+++ b/od-win32/win32gui.cpp
@@ -9029,7 +9029,6 @@ static void values_to_chipsetdlg2 (HWND hDlg)
 	CheckDlgButton(hDlg, IDC_CS_1MCHIPJUMPER, workprefs.cs_1mchipjumper || workprefs.chipmem.size >= 0x100000);
 	CheckDlgButton(hDlg, IDC_CS_BYTECUSTOMWRITEBUG, workprefs.cs_bytecustomwritebug);
 	CheckDlgButton(hDlg, IDC_CS_COMPOSITECOLOR, workprefs.cs_color_burst);
-	CheckDlgButton(hDlg, IDC_CS_OCSHBLANKBUG, workprefs.cs_ocshblankbug);
 	CheckDlgButton(hDlg, IDC_CS_TOSHIBAGARY, workprefs.cs_toshibagary);
 	CheckDlgButton(hDlg, IDC_CS_ROMISSLOW, workprefs.cs_romisslow);
 	CheckDlgButton(hDlg, IDC_CS_CIA, workprefs.cs_ciatype[0]);
@@ -9122,7 +9121,6 @@ static void values_from_chipsetdlg2 (HWND hDlg, UINT msg, WPARAM wParam, LPARAM
 	workprefs.cs_1mchipjumper = ischecked(hDlg, IDC_CS_1MCHIPJUMPER);
 	workprefs.cs_bytecustomwritebug = ischecked(hDlg, IDC_CS_BYTECUSTOMWRITEBUG);
 	workprefs.cs_color_burst = ischecked(hDlg, IDC_CS_COMPOSITECOLOR);
-	workprefs.cs_ocshblankbug = ischecked(hDlg, IDC_CS_OCSHBLANKBUG);
 	workprefs.cs_toshibagary = ischecked(hDlg, IDC_CS_TOSHIBAGARY);
 	workprefs.cs_romisslow = ischecked(hDlg, IDC_CS_ROMISSLOW);
 	workprefs.cs_ciatype[0] = workprefs.cs_ciatype[1] = ischecked(hDlg, IDC_CS_CIA);
@@ -9213,7 +9211,6 @@ static void enable_for_chipsetdlg2 (HWND hDlg)
 	ew(hDlg, IDC_CS_1MCHIPJUMPER, e && workprefs.chipmem.size < 0x100000);
 	ew(hDlg, IDC_CS_BYTECUSTOMWRITEBUG, e);
 	ew(hDlg, IDC_CS_COMPOSITECOLOR, e);
-	ew(hDlg, IDC_CS_OCSHBLANKBUG, e);
 	ew(hDlg, IDC_CS_TOSHIBAGARY, e);
 	ew(hDlg, IDC_CS_ROMISSLOW, e);
 	ew(hDlg, IDC_CS_UNMAPPED, e);