Rectified some constants related to NTSC overscan (#852)

dirkwhoffmann · Dec 29, 2024 · dae01fb · dae01fb
1 parent 008a068
commit dae01fb
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Showing 4 changed files with 8 additions and 7 deletions.
diff --git a/Emulator/Base/Constants.h b/Emulator/Base/Constants.h
@@ -104,8 +104,8 @@ static const isize VBLANK_MAX_PAL = 0x19;   // Last VBLANK line
 static const isize VBLANK_CNT_PAL = 0x1A;   // VBLANK_MAX - VBLANK_MIN + 1
 
 static const isize VBLANK_MIN_NTSC = 0x00;  // First VBLANK line
-static const isize VBLANK_MAX_NTSC = 0x14;  // Last VBLANK line
-static const isize VBLANK_CNT_NTSC = 0x15;  // VBLANK_MAX - VBLANK_MIN + 1
+static const isize VBLANK_MAX_NTSC = 0x13;  // Last VBLANK line
+static const isize VBLANK_CNT_NTSC = 0x14;  // VBLANK_MAX - VBLANK_MIN + 1
 
 
 //

diff --git a/Emulator/Components/Agnus/Agnus.cpp b/Emulator/Components/Agnus/Agnus.cpp
@@ -586,7 +586,7 @@ Agnus::updateSpriteDMA()
     isize v = pos.v + 1;
 
     // Reset the vertical trigger coordinates in line 25 (PAL) or 20 (NTSC)
-    isize resetLine = isPAL() ? 25 : 20;
+    isize resetLine = isPAL() ? 25 : 19;
     if (v == resetLine && sprdma()) {
         for (isize i = 0; i < 8; i++) sprVStop[i] = resetLine;
         return;

diff --git a/Emulator/Components/Agnus/Agnus.h b/Emulator/Components/Agnus/Agnus.h
@@ -416,7 +416,7 @@ class Agnus : public SubComponent, public Inspectable<AgnusInfo, AgnusStats> {
 public:
 
     // Indicates if the electron beam is inside the VBLANK area
-    bool inVBlankArea(isize posv) const { return posv < (isPAL() ? 26 : 21); }
+    bool inVBlankArea(isize posv) const { return posv < (isPAL() ? 26 : 20); }
     bool inVBlankArea() const { return inVBlankArea(pos.v); }
 
     // Indicates if the current rasterline is the last line in this frame

diff --git a/Emulator/Components/Agnus/Sequencer/Sequencer.cpp b/Emulator/Components/Agnus/Sequencer/Sequencer.cpp
@@ -46,8 +46,9 @@ Sequencer::eolHandler()
     }
 
     // Check the vertical DIW flipflop
-    if (agnus.pos.v == vstop || agnus.inLastRasterline()) {
-
+    // if (agnus.pos.v == vstop || agnus.inLastRasterline()) {
+    if (agnus.pos.v == vstop || agnus.pos.v == (agnus.isPAL() ? 312 : 262)) {
+
         trace(SEQ_DEBUG, "eolHandler: Vertical flipflop off\n");
         ddfInitial.bpv = ddf.bpv = false;
         hsyncActions |= UPDATE_SIG_RECORDER;
@@ -71,7 +72,7 @@ Sequencer::eolHandler()
         newDmaDAS = agnus.dmacon & 0b111111;
 
         // Disable sprites outside the sprite DMA area
-        if (agnus.pos.v < (agnus.isPAL() ? 25 : 20) || agnus.pos.v >= agnus.pos.vMax()) {
+        if (agnus.pos.v < (agnus.isPAL() ? 25 : 19) || agnus.pos.v >= agnus.pos.vMax()) {
             newDmaDAS &= 0b011111;
         }
     }