From: Toni Wilen <twilen@winuae.net>
Date: Sat, 4 Apr 2026 13:07:57 +0000 (+0300)
Subject: Update display setup calculation
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=10b7ba39f89a4f552d9ed229ba2aa5ef3e92abcd;p=francis%2Fwinuae.git

Update display setup calculation
---

diff --git a/custom.cpp b/custom.cpp
index ea7721d7..249e0a11 100644
--- a/custom.cpp
+++ b/custom.cpp
@@ -1558,94 +1558,70 @@ void resetfulllinestate(void)
 	displayreset_delayed |= 16 | 8 | 4 | 2;
 }
 
-void compute_framesync(void)
+static bool line_is_doubled(void)
 {
-	struct vidbuf_description *vidinfo = &adisplays[0].gfxvidinfo;
-	struct amigadisplay *ad = &adisplays[0];
-	int islace = interlace_seen ? 1 : 0;
-	int isntsc = (beamcon0 & BEAMCON0_PAL) ? 0 : 1;
-	bool found = false;
-
-	if (islace) {
-		vblank_hz = vblank_hz_lace;
-	} else if (lof_store) {
-		vblank_hz = vblank_hz_lof;
-	} else {
-		vblank_hz = vblank_hz_shf;
+	if (doflickerfix_active()) {
+		return true;
 	}
+	if (!interlace_seen && doublescan <= 0 && currprefs.gfx_vresolution && currprefs.gfx_pscanlines > 1) {
+		return true;
+	}
+	if ((doublescan <= 0 || interlace_seen > 0) && currprefs.gfx_vresolution && currprefs.gfx_iscanlines) {
+		return true;
+	}
+	if (currprefs.gfx_vresolution && (doublescan <= 0 || interlace_seen > 0)) {
+		return true;
+	}
+	return false;
+}
 
-	set_drawbuffer();
-	struct vidbuffer *vb = vidinfo->inbuffer;
-
-	vblank_hz = target_adjust_vblank_hz(0, vblank_hz);
-
-	struct chipset_refresh *cr = get_chipset_refresh(&currprefs);
-	while (cr) {
-		float v = -1;
-		if (!ad->picasso_on && !ad->picasso_requested_on) {
-			if (isvsync_chipset ()) {
-				if (!currprefs.gfx_variable_sync) {
-					if (cr->index == CHIPSET_REFRESH_PAL || cr->index == CHIPSET_REFRESH_NTSC) {
-						if ((fabs(vblank_hz - 50.0f) < 1 || fabs(vblank_hz - 60.0f) < 1 || fabs(vblank_hz - 100.0) < 1 || fabs(vblank_hz - 120.0f) < 1) && currprefs.gfx_apmode[0].gfx_vsync == 2 && currprefs.gfx_apmode[0].gfx_fullscreen > 0) {
-							vsync_switchmode(0, (int)vblank_hz);
-						}
-					}
-					if (isvsync_chipset() < 0) {
+static void update_display_vars(void)
+{
+	struct vidbuf_description* vidinfo = &adisplays[0].gfxvidinfo;
+	struct vidbuffer* vb = vidinfo->inbuffer;
+	int isntsc = (beamcon0 & BEAMCON0_PAL) ? 0 : 1;
+	int islace = interlace_seen ? 1 : 0;
+	int res = GET_RES_AGNUS(bplcon0);
+	int eres = 0;
 
-						float v2;
-						v2 = target_getcurrentvblankrate(0);
-						if (!cr->locked)
-							v = v2;
-					} else if (isvsync_chipset() > 0) {
-						if (currprefs.gfx_apmode[0].gfx_refreshrate) {
-							v = (float)abs(currprefs.gfx_apmode[0].gfx_refreshrate);
-						}
-					}
-				}
-			} else {
-				if (cr->locked == false) {
-					changed_prefs.chipset_refreshrate = currprefs.chipset_refreshrate = vblank_hz;
-					cfgfile_parse_lines (&changed_prefs, cr->commands, -1);
-					if (cr->commands[0]) {
-						write_log(_T("CMD1: '%s'\n"), cr->commands);
-					}
-					break;
-				} else {
-					v = cr->rate;
-				}
-			}
-			if (v < 0)
-				v = cr->rate;
-			if (v > 0) {
-				changed_prefs.chipset_refreshrate = currprefs.chipset_refreshrate = v;
-				cfgfile_parse_lines (&changed_prefs, cr->commands, -1);
-				if (cr->commands[0]) {
-					write_log(_T("CMD2: '%s'\n"), cr->commands);
-				}
+	doublescan = 0;
+	doublescan2x = 0;
+	if (currprefs.gfx_scandoubler && doublescan == 0) {
+		doublescan = -1;
+	}
+	int hpixels = maxhpos_display * 2;
+	if (currprefs.gfx_resolution == RES_LORES) {
+		hpixels /= 2;
+	} else if (currprefs.gfx_resolution == RES_SUPERHIRES) {
+		hpixels *= 2;
+	}
+	int vpixels = vsync_lines - minfirstline;
+	int hpixelsd = hpixels * 85 / 100;
+	if (hpixelsd < vpixels) {
+		doublescan = 1;
+		if (programmedmode == 2) {
+			programmedmode = 1;
+		}
+		hpixelsd *= 2;
+	}
+	if (currprefs.gfx_keep_aspect) {
+		bool dbl = line_is_doubled();
+		if (dbl) {
+			vpixels *= 2;
+		}
+		if (hpixelsd < vpixels) {
+			doublescan2x = 1;
+			hpixelsd *= 2;
+			if (hpixelsd < vpixels) {
+				doublescan2x = 2;
 			}
-		} else {
-			if (cr->locked == false)
-				v = vblank_hz;
-			else
-				v = cr->rate;
-			changed_prefs.chipset_refreshrate = currprefs.chipset_refreshrate = v;
-			cfgfile_parse_lines (&changed_prefs, cr->commands, -1);
-			if (cr->commands[0]) {
-				write_log(_T("CMD3: '%s'\n"), cr->commands);
+		} else if (hpixelsd > vpixels * 2) {
+			doublescan2x = -1;
+			if (hpixelsd > vpixels * 4) {
+				doublescan2x = -2;
 			}
 		}
-		found = true;
-		break;
-	}
-	if (!found) {
-		changed_prefs.chipset_refreshrate = currprefs.chipset_refreshrate = vblank_hz;
 	}
-	stored_chipset_refresh = cr;
-	vb->inxoffset = -1;
-	vb->inyoffset = -1;
-
-	int res = GET_RES_AGNUS(bplcon0);
-	int eres = 0;
 
 	int res2 = currprefs.gfx_resolution;
 
@@ -1680,6 +1656,7 @@ void compute_framesync(void)
 	if (currprefs.gfx_extraheight > 0) {
 		vb->extraheight = currprefs.gfx_extraheight << vres2;
 	}
+
 	int vblines = current_linear_vblank_lines;
 	if (currprefs.cs_hvcsync >= HVSYNC_SYNCPOS) {
 		vblines = LINES_AFTER_VSYNC;
@@ -1733,18 +1710,6 @@ void compute_framesync(void)
 
 	hblank_hz = (currprefs.ntscmode ? CHIPSET_CLOCK_NTSC : CHIPSET_CLOCK_PAL) / (maxhpos + (linetoggle ? 0.5f : 0.0f));
 
-	write_log(_T("%s mode%s%s V=%.4fHz H=%0.4fHz (%dx%d+%d) IDX=%d (%s) D=%d RTG=%d/%d\n"),
-		isntsc ? _T("NTSC") : _T("PAL"),
-		islace ? _T(" lace") : _T(""),
-		doublescan > 0 ? _T(" dblscan") : _T(""),
-		vblank_hz,
-		hblank_hz,
-		maxhpos, maxvpos, lof_store ? 1 : 0,
-		cr ? cr->index : -1,
-		cr != NULL && cr->label != NULL ? cr->label : _T("<?>"),
-		currprefs.gfx_apmode[ad->picasso_on ? 1 : 0].gfx_display, ad->picasso_on, ad->picasso_requested_on
-	);
-
 #ifdef PICASSO96
 	init_hz_p96(0);
 #endif
@@ -1777,21 +1742,106 @@ void compute_framesync(void)
 	resetfulllinestate();
 }
 
-static bool line_is_doubled(void)
+
+void compute_framesync(void)
 {
-	if (doflickerfix_active()) {
-		return true;
-	}
-	if (!interlace_seen && doublescan <= 0 && currprefs.gfx_vresolution && currprefs.gfx_pscanlines > 1) {
-		return true;
+	struct vidbuf_description *vidinfo = &adisplays[0].gfxvidinfo;
+	struct amigadisplay *ad = &adisplays[0];
+	int isntsc = (beamcon0 & BEAMCON0_PAL) ? 0 : 1;
+	int islace = interlace_seen ? 1 : 0;
+	bool found = false;
+
+	if (islace) {
+		vblank_hz = vblank_hz_lace;
+	} else if (lof_store) {
+		vblank_hz = vblank_hz_lof;
+	} else {
+		vblank_hz = vblank_hz_shf;
 	}
-	if ((doublescan <= 0 || interlace_seen > 0) && currprefs.gfx_vresolution && currprefs.gfx_iscanlines) {
-		return true;
+
+	set_drawbuffer();
+	struct vidbuffer *vb = vidinfo->inbuffer;
+
+	vblank_hz = target_adjust_vblank_hz(0, vblank_hz);
+
+	struct chipset_refresh *cr = get_chipset_refresh(&currprefs);
+	while (cr) {
+		float v = -1;
+		if (!ad->picasso_on && !ad->picasso_requested_on) {
+			if (isvsync_chipset ()) {
+				if (!currprefs.gfx_variable_sync) {
+					if (cr->index == CHIPSET_REFRESH_PAL || cr->index == CHIPSET_REFRESH_NTSC) {
+						if ((fabs(vblank_hz - 50.0f) < 1 || fabs(vblank_hz - 60.0f) < 1 || fabs(vblank_hz - 100.0) < 1 || fabs(vblank_hz - 120.0f) < 1) && currprefs.gfx_apmode[0].gfx_vsync == 2 && currprefs.gfx_apmode[0].gfx_fullscreen > 0) {
+							vsync_switchmode(0, (int)vblank_hz);
+						}
+					}
+					if (isvsync_chipset() < 0) {
+
+						float v2;
+						v2 = target_getcurrentvblankrate(0);
+						if (!cr->locked)
+							v = v2;
+					} else if (isvsync_chipset() > 0) {
+						if (currprefs.gfx_apmode[0].gfx_refreshrate) {
+							v = (float)abs(currprefs.gfx_apmode[0].gfx_refreshrate);
+						}
+					}
+				}
+			} else {
+				if (cr->locked == false) {
+					changed_prefs.chipset_refreshrate = currprefs.chipset_refreshrate = vblank_hz;
+					cfgfile_parse_lines (&changed_prefs, cr->commands, -1);
+					if (cr->commands[0]) {
+						write_log(_T("CMD1: '%s'\n"), cr->commands);
+					}
+					break;
+				} else {
+					v = cr->rate;
+				}
+			}
+			if (v < 0)
+				v = cr->rate;
+			if (v > 0) {
+				changed_prefs.chipset_refreshrate = currprefs.chipset_refreshrate = v;
+				cfgfile_parse_lines (&changed_prefs, cr->commands, -1);
+				if (cr->commands[0]) {
+					write_log(_T("CMD2: '%s'\n"), cr->commands);
+				}
+			}
+		} else {
+			if (cr->locked == false)
+				v = vblank_hz;
+			else
+				v = cr->rate;
+			changed_prefs.chipset_refreshrate = currprefs.chipset_refreshrate = v;
+			cfgfile_parse_lines (&changed_prefs, cr->commands, -1);
+			if (cr->commands[0]) {
+				write_log(_T("CMD3: '%s'\n"), cr->commands);
+			}
+		}
+		found = true;
+		break;
 	}
-	if (currprefs.gfx_vresolution && (doublescan <= 0 || interlace_seen > 0)) {
-		return true;
+	if (!found) {
+		changed_prefs.chipset_refreshrate = currprefs.chipset_refreshrate = vblank_hz;
 	}
-	return false;
+	stored_chipset_refresh = cr;
+	vb->inxoffset = -1;
+	vb->inyoffset = -1;
+
+	update_display_vars();
+
+	write_log(_T("%s mode%s%s V=%.4fHz H=%0.4fHz (%dx%d+%d) IDX=%d (%s) D=%d RTG=%d/%d\n"),
+		isntsc ? _T("NTSC") : _T("PAL"),
+		islace ? _T(" lace") : _T(""),
+		doublescan > 0 ? _T(" dblscan") : _T(""),
+		vblank_hz,
+		hblank_hz,
+		maxhpos, maxvpos, lof_store ? 1 : 0,
+		cr ? cr->index : -1,
+		cr != NULL && cr->label != NULL ? cr->label : _T("<?>"),
+		currprefs.gfx_apmode[ad->picasso_on ? 1 : 0].gfx_display, ad->picasso_on, ad->picasso_requested_on
+	);
 }
 
 /* set PAL/NTSC or custom timing variables */
@@ -1803,8 +1853,6 @@ static void init_beamcon0(void)
 
 	beamcon0 = new_beamcon0;
 
-	doublescan = 0;
-	doublescan2x = 0;
 	programmedmode = 0;
 	lines_after_beamcon_change = 5;
 
@@ -1841,12 +1889,10 @@ static void init_beamcon0(void)
 	if (!isntsc) {
 		maxvpos = MAXVPOS_PAL;
 		maxhpos = MAXHPOS_PAL;
-		//minfirstline = VBLANK_STOP_PAL;
 		vblank_hz_nom = vblank_hz = CHIPSET_CLOCK_PAL / ((float)display_maxvpos * display_maxhpos);
 	} else {
 		maxvpos = MAXVPOS_NTSC;
 		maxhpos = MAXHPOS_NTSC;
-		//minfirstline = VBLANK_STOP_NTSC;
 		vblank_hz_nom = vblank_hz = CHIPSET_CLOCK_NTSC / ((float)display_maxvpos * display_maxhpos);
 		halfhpos = (beamcon0 & BEAMCON0_LOLDIS) ? 0 : 0.5f;
 	}
@@ -1854,56 +1900,6 @@ static void init_beamcon0(void)
 	vblank_hz_lof = clk / ((display_maxvpos + 1.0f) * (display_maxhpos + halfhpos));
 	vblank_hz_lace = clk / ((display_maxvpos + 0.5f) * (display_maxhpos + halfhpos));
 
-#if 0
-	display_hstart_cyclewait_end = 4;
-	if (beamcon0_has_hsync) {
-		int hblen = current_linear_hblen * 2;
-		display_hstart_cyclewait = 4;
-		if (currprefs.gfx_overscanmode >= OVERSCANMODE_ULTRA) {
-			display_hstart_cyclewait_end = 0;
-		} else {
-			if (aexthblanken && !(beamcon0 & BEAMCON0_VARBEAMEN) && hblen > 0) {
-				maxhpos_display = maxhpos - ((hblen + 1) / 2);
-				hsstop_detect = current_linear_hs_hb_dist * 2 + 4;
-				display_hstart_cyclewait_end += hblen / 2 - 4;
-				display_hstart_cyclewait = current_linear_hs_hb_dist;
-				if (display_hstart_cyclewait < 0) {
-					display_hstart_cyclewait = 0;
-				}
-				display_hstart_cyclewait_end = hblen / 2 - display_hstart_cyclewait;
-				display_hstart_cyclewait += 1;
-			} else {
-				// hardwired
-				int hbstrtx = 0x10;
-				int hbstopx = ecs_denise ? 0x5d : 0x5e;
-				int hblen = hbstopx - hbstrtx;
-				maxhpos_display = maxhpos - (hblen / 2);
-				if (beamcon0_has_hsync) {
-					hsstop_detect = hsstrt * 2;
-				} else {
-					hsstop_detect = hsstop_detect2;
-				}
-
-				display_hstart_cyclewait = hbstopx / 2 - hsstrt;
-				//display_hstart_cyclewait += hsstrt_delay;
-			}
-		}
-	} else {
-		display_hstart_cyclewait = 0;
-		display_hstart_cyclewait_end = 0;
-		if (currprefs.gfx_overscanmode == OVERSCANMODE_BROADCAST) {
-			display_hstart_cyclewait = 32;
-			display_hstart_cyclewait_end = 9;
-		} else if (currprefs.gfx_overscanmode <= OVERSCANMODE_OVERSCAN) {
-			display_hstart_cyclewait = 32;
-			display_hstart_cyclewait_end = 10;
-		} else if (currprefs.gfx_overscanmode == OVERSCANMODE_EXTREME) {
-			display_hstart_cyclewait = 22;
-			display_hstart_cyclewait_end = 5;
-		}
-	}
-#endif
-
 	if (beamcon0 & BEAMCON0_VARBEAMEN) {
 		// programmable scanrates (ECS Agnus)
 		if (vtotal >= MAXVPOS) {
@@ -1938,7 +1934,6 @@ static void init_beamcon0(void)
 	int hsylen = current_agnus_hslen_cck;
 	hsylen *= 2;
 	hsylen += currprefs.cs_hsyncadjust / 4;
-	//hsstop_detect = hbe;
 	if (hbe < hsylen) {
 		hbe = hsylen;
 	}
@@ -1964,7 +1959,6 @@ static void init_beamcon0(void)
 		maxhpos_display = hsync_ccks * 2;
 		display_hstart_cyclewait_start = 0;
 		display_hstart_cyclewait_end = 0;
-		//minfirstline = 0;
 	}
 
 	if (display_hstart_cyclewait_start < 0) {
@@ -1981,130 +1975,6 @@ static void init_beamcon0(void)
 		denisehtotal += 1 << (CCK_SHRES_SHIFT - 1);
 	}
 
-#if 0
-	// calculate max possible display width in lores pixels
-	if ((beamcon0 & BEAMCON0_VARBEAMEN) && beamcon0_has_hsync) {
-		int hsstrt_delay = 2;
-		display_hstart_cyclewait = 0;
-		display_hstart_cyclewait_end = 0;
-		// assume VGA-like monitor if VARBEAMEN
-		if (currprefs.gfx_overscanmode >= OVERSCANMODE_ULTRA) {
-			maxhpos_display = maxhpos + 7;
-			if (beamcon0_has_hsync) {
-				hsstop_detect = hsstrt * 2;
-				if (hsstop_detect > maxhpos / 2 * 2 || hsstop_detect < 4 * 2) {
-					hsstop_detect = 4 * 2;
-				}
-			} else {
-				hsstop_detect = 4 * 2;
-			}
-			minfirstline = 0;
-		} else {
-			//int hblen = current_linear_hblen * 2;
-
-			if (aexthblanken && hblen > 0) {
-
-				maxhpos_display = maxhpos - ((hblen + 1) / 2);
-				hsstop_detect = hbe;
-				display_hstart_cyclewait_end += hblen / 2;
-				display_hstart_cyclewait = hbe / 2;
-				if (display_hstart_cyclewait < 0)	 {
-					display_hstart_cyclewait = 0;
-				}
-				display_hstart_cyclewait_end = hblen / 2 - display_hstart_cyclewait;
-				display_hstart_cyclewait += 1;
-
-			} else {
-
-				// hardwired
-				int hbstrtx = 0x10;
-				int hbstopx = ecs_denise ? 0x5d : 0x5e;
-				int hblen = hbstopx - hbstrtx;
-				maxhpos_display = maxhpos - (hblen / 2);
-				if (beamcon0_has_hsync) {
-					hsstop_detect = hsstrt * 2;
-				} else {
-					hsstop_detect = hsstop_detect2;
-				}
-
-				display_hstart_cyclewait = hbstopx / 2 - hsstrt;
-				display_hstart_cyclewait += hsstrt_delay;
-			}
-
-			if (currprefs.gfx_overscanmode >= OVERSCANMODE_EXTREME) {
-				int diff = (maxhpos - 2) - maxhpos_display;
-				if (diff > 0) {
-					hsstop_detect -= (diff / 2) * 2;
-				}
-				maxhpos_display = maxhpos - 2;
-			}
-
-			maxhpos_display *= 2;
-			if (display_hstart_cyclewait_end < 0) {
-				display_hstart_cyclewait_end = 0;
-			}
-		}
-
-	} else if (!(beamcon0 & BEAMCON0_VARBEAMEN)) {
-
-		maxhpos_display = maxhpos - (hblen / 2);
-		maxhpos_display *= 2;
-		maxhpos_display++;
-		hsstop_detect = hbe;
-		display_hstart_cyclewait = hbe / 2 + 3;
-		if (display_hstart_cyclewait < 0) {
-			display_hstart_cyclewait = 0;
-		}
-		display_hstart_cyclewait_end = hblen / 2 - display_hstart_cyclewait + 1;
-		display_hstart_cyclewait += 1;
-
-
-		//maxhpos_display = AMIGA_WIDTH_MAX;
-		//hsstop_detect = hsstop_detect2;
-
-		if (beamcon0 & bemcon0_hsync_mask) {
-			if (currprefs.gfx_overscanmode < OVERSCANMODE_BROADCAST) {
-				hsstop_detect += 7;
-			} else if (currprefs.gfx_overscanmode == OVERSCANMODE_BROADCAST) {
-				hsstop_detect += 5;
-			} else if (currprefs.gfx_overscanmode >= OVERSCANMODE_ULTRA) {
-				maxhpos_display += EXTRAWIDTH_ULTRA;
-				minfirstline = 0;
-				hsstop_detect = hsyncstartpos_start_cycles * 2 - 4;
-			}
-		} else {
-
-			if (currprefs.gfx_overscanmode >= OVERSCANMODE_ULTRA) {
-				maxhpos_display += EXTRAWIDTH_ULTRA;
-				hsstop_detect = 18 * 2;
-				minfirstline = 1;
-			}
-		}
-
-	}
-
-	if (!(beamcon0 & BEAMCON0_VARBEAMEN) || !beamcon0_has_hsync) {
-		if (currprefs.gfx_overscanmode < OVERSCANMODE_BROADCAST) {
-			// one pixel row missing from right border if OCS
-			if (!ecs_denise) {
-				maxhpos_display--;
-			}
-			minfirstline++;
-			if (maxvpos_display_vsync > 0) {
-				maxvpos_display_vsync--;
-			} else {
-				maxvpos_display--;
-			}
-		} else if (currprefs.gfx_overscanmode == OVERSCANMODE_EXTREME) {
-			maxhpos_display += EXTRAWIDTH_EXTREME;
-			hsstop_detect -= 4;
-		} else if (currprefs.gfx_overscanmode == OVERSCANMODE_BROADCAST) {
-			maxhpos_display += EXTRAWIDTH_BROADCAST;
-			hsstop_detect -= 1;
-		}
-	}
-#endif
-
 	if (currprefs.gfx_extrawidth > 0) {
 		maxhpos_display += currprefs.gfx_extrawidth;
 	}
@@ -2136,54 +2006,14 @@ static void init_beamcon0(void)
 		display_vblankend_skip = 2;
 	}
 
-#if 0
-	if ((beamcon0 & BEAMCON0_VARVBEN) && (beamcon0 & bemcon0_vsync_mask)) {
-		if (minfirstline < vsync_startline) {
-			minfirstline = vsync_startline;
-			minfirstline++;
-		}
-		if (minfirstline > vsync_lines / 2) {
-			minfirstline = vsync_startline;
-			minfirstline++;
-		}
-	} else if (beamcon0 & BEAMCON0_VARVBEN) {
-		if (minfirstline > vbstop) {
-			minfirstline = vbstop;
-			if (minfirstline < 3) {
-				minfirstline = 3;
-			}
-		}
-	}
-#endif
 	if (beamcon0 & (BEAMCON0_VARVBEN | bemcon0_vsync_mask)) {
 		programmedmode = 2;
 	}
 
-	int eh = currprefs.gfx_extraheight;
-	if (eh > 0) {
-		if (beamcon0 & bemcon0_vsync_mask) {
-			minfirstline -= eh / 2;
-		} else {
-			minfirstline -= eh / 2;
-		}
-	}
-
 	if (display_hstart_cyclewait_end < 0) {
 		display_hstart_cyclewait_end = 0;
 	}
 
-//	if (minfirstline < vsync_startline) {
-//		minfirstline = vsync_startline;
-//	}
-//	if (minfirstline >= vsync_lines) {
-//		minfirstline = vsync_lines - 1;
-//	}
-//	if (beamcon0 & bemcon0_vsync_mask) {
-//		if (minfirstline < vsync_startline) {
-//			minfirstline = vsync_startline;
-//		}
-//	}
-
 	if (beamcon0 & BEAMCON0_VARBEAMEN) {
 		float half = (beamcon0 & BEAMCON0_PAL) ? 0: ((beamcon0 & BEAMCON0_LOLDIS) ? 0 : 0.5f);
 		vblank_hz_nom = vblank_hz = clk / (vsync_lines * (hsync_ccks + half));
@@ -2197,40 +2027,6 @@ static void init_beamcon0(void)
 		programmedmode = 2;
 	}
 
-	int hpixels = maxhpos_display * 2;
-	if (currprefs.gfx_resolution == RES_LORES) {
-		hpixels /= 2;
-	} else if (currprefs.gfx_resolution == RES_SUPERHIRES) {
-		hpixels *= 2;
-	}
-	int vpixels = vsync_lines - minfirstline;
-	int hpixelsd = hpixels * 85 / 100;
-	if (hpixelsd < vpixels) {
-		doublescan = 1;
-		if (programmedmode == 2) {
-			programmedmode = 1;
-		}
-		hpixelsd *= 2;
-	}
-	if (currprefs.gfx_keep_aspect) {
-		bool dbl = line_is_doubled();
-		if (dbl) {
-			vpixels *= 2;
-		}
-		if (hpixelsd < vpixels) {
-			doublescan2x = 1;
-			hpixelsd *= 2;
-			if (hpixelsd < vpixels) {
-				doublescan2x = 2;
-			}
-		} else if (hpixelsd > vpixels * 2) {
-			doublescan2x = -1;
-			if (hpixelsd > vpixels * 4) {
-				doublescan2x = -2;
-			}
-		}
-	}
-
 	if (maxvpos_nom >= MAXVPOS) {
 		maxvpos_nom = MAXVPOS;
 	}
@@ -2238,9 +2034,7 @@ static void init_beamcon0(void)
 	if (maxvpos_display >= MAXVPOS) {
 		maxvpos_display = MAXVPOS;
 	}
-	if (currprefs.gfx_scandoubler && doublescan == 0) {
-		doublescan = -1;
-	}
+
 	/* limit to sane values */
 	if (vblank_hz < 10) {
 		vblank_hz = 10;
@@ -10197,7 +9991,7 @@ static void check_vsyncs_fast(void)
 	if (beamcon0_has_hsync) {
 		count_hsyncs(hsstrt, hsstop);
 	} else {
-		count_hsyncs(35, 18);
+		count_hsyncs(18, 35);
 	}
 	if (programmed_register_accessed_v && programmed_register_accessed_h) {
 		if (hcenter < maxhpos) {
diff --git a/drawing.cpp b/drawing.cpp
index 84eec99b..4d5e33bf 100644
--- a/drawing.cpp
+++ b/drawing.cpp
@@ -608,7 +608,7 @@ int coord_native_to_amiga_x(int x)
 
 int coord_native_to_amiga_y(int y)
 {
-	y += min_ypos_for_screen;
+	y += (minfirstline_linear + LINES_AFTER_VSYNC) << linedbl;
 	y >>= linedbl;
 	return y;
 }