[PCE] cap active display to 242 lines, fixes Puzzle Boy (requests 512)

BizHawk.Emulation/Consoles/PC Engine/Compat.txt

@@ -23,12 +23,9 @@ Tiger Road        - On second level, sprites should be getting masked from the t
 Bouken Danshaku Don - The Lost Sunheart (J)    - Uses LFO in intro sound strongly!
 Eagan's Rendered Sprite Demo by Eagan Rackley (PD) - demonstrates sprites that shouldnt be displayed
 Games Express CD Card 1993 - dont forget to treat as a turbocd system card
-Puzzle Boy(J) - screen vert height is fucked up...needs to be masked or just clipped?
 Yo, Bro - game screen black, can hear game playing though
 Youkai Douchuuki(J) - part of bg missing? wtf.
 
-Note, check overdump roms From A  - Final Lap Twin
-
 ===================================
 Games that need TV Emulation (to varying degrees)
 ===================================
@@ -69,4 +66,5 @@ Stuff I Fixed That's Not In Other Docs:
   4 color modes. It appears to be the only game that requires this, and it's a shitty game. :(
 + The ROM of Paranoia (J) that is commonly labeled as the authoritative dump - I assume its a bad
   dump, because it dies during the 3rd stage on ALL EMULATORS. Alternative versions of the rom 
-  work fine.
+  work fine.
++ Puzzle Boy - requests frame height of 512... cap active display to 242 lines  

BizHawk.Emulation/Consoles/PC Engine/VDC.Render.cs

@@ -100,6 +100,9 @@ namespace BizHawk.Emulation.Consoles.TurboGrafx
 
         public void RenderScanLine()
         {
+            if (ActiveLine >= FrameHeight)
+                return;
+
             RenderBackgroundScanline();
             RenderSpritesScanline();
         }

BizHawk.Emulation/Consoles/PC Engine/VDC.cs

@@ -147,16 +147,14 @@ namespace BizHawk.Emulation.Consoles.TurboGrafx
                 case HDR: // Horizontal Display Register - update framebuffer size
                     FrameWidth = RequestedFrameWidth;
                     if (FrameBuffer.Length != FrameWidth * FrameHeight)
-                    {
                         FrameBuffer = new int[FrameWidth*FrameHeight];
-                    }
                     break;
                 case VDW: // Vertical Display Word? - update framebuffer size
                     FrameHeight = RequestedFrameHeight;
+                    if (FrameHeight > 242)
+                        FrameHeight = 242;
                     if (FrameBuffer.Length != FrameWidth * FrameHeight)
-                    {
                         FrameBuffer = new int[FrameWidth * FrameHeight];
-                    }
                     break;
                 case LENR: // Initiate DMA transfer
                     DmaRequested = true;