M src/gb/memory.c → src/gb/memory.c

@@ -340,7 +340,11 @@ gb->cpu->cycles += 2;
 	if (gb->memory.hdmaRemaining) {
 		gb->memory.hdmaNext += 2;
 	} else {
-		gb->memory.io[REG_HDMA5] |= 0x80;
+		if (gb->memory.isHdma) {
+			--gb->memory.io[REG_HDMA5];
+		} else {
+			gb->memory.io[REG_HDMA5] |= 0x80;
+		}
 	}
 }
 

M src/gb/video.c → src/gb/video.c

@@ -178,6 +178,10 @@ if (GBRegisterSTATIsHblankIRQ(video->stat)) {
 					video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
 					GBUpdateIRQs(video->p);
 				}
+				if (video->ly < GB_VIDEO_VERTICAL_PIXELS && video->p->memory.isHdma && video->p->memory.io[REG_HDMA5] != 0xFF) {
+					video->p->memory.hdmaRemaining = 0x10;
+					video->p->memory.hdmaNext = video->p->cpu->cycles;
+				}
 				break;
 			}
 			video->stat = GBRegisterSTATSetMode(video->stat, video->mode);