From 80b1275e0791a381b71b78f9daab30ff173f887a Mon Sep 17 00:00:00 2001
From: Lior Halphon <LIJI32@gmail.com>
Date: Sun, 18 Mar 2018 20:08:45 +0200
Subject: [PATCH 1/2] Fix stat_lyc_onoff

---
 Core/display.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/Core/display.c b/Core/display.c
index dda9fab..1adcc50 100755
--- a/Core/display.c
+++ b/Core/display.c
@@ -311,11 +311,9 @@ static void update_display_state(GB_gameboy_t *gb, uint8_t cycles)
     if (!(gb->io_registers[GB_IO_LCDC] & 0x80)) {
         /* LCD is disabled, state is constant */
         
-        /* When the LCD is off, LY is 0 and STAT mode is 0.
-           Todo: Verify the LY=LYC flag should be on. */
+        /* When the LCD is off, LY is 0 and STAT mode is 0. */
         gb->io_registers[GB_IO_LY] = 0;
         gb->io_registers[GB_IO_STAT] &= ~3;
-        gb->io_registers[GB_IO_STAT] |= 4;
         gb->effective_scx = gb->io_registers[GB_IO_SCX];
         if (gb->hdma_on_hblank) {
             gb->hdma_on_hblank = false;

From b50c97f4a71f2a3d535477ee88c0469f42151cd5 Mon Sep 17 00:00:00 2001
From: Lior Halphon <LIJI32@gmail.com>
Date: Mon, 19 Mar 2018 20:01:31 +0200
Subject: [PATCH 2/2] Prevent starting HDMA in the middle of an instruction,
 making both the CPU and DMA access memory at the same time. Closes #47

---
 Core/display.c | 3 +--
 Core/gb.h      | 1 +
 Core/z80_cpu.c | 6 ++++++
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/Core/display.c b/Core/display.c
index 1adcc50..b55d66f 100755
--- a/Core/display.c
+++ b/Core/display.c
@@ -528,8 +528,7 @@ static void update_display_state(GB_gameboy_t *gb, uint8_t cycles)
             }
             else if (position_in_line == MODE2_LENGTH + MODE3_LENGTH + stat_delay + scx_delay + 16) {
                 if (gb->hdma_on_hblank) {
-                    gb->hdma_on = true;
-                    gb->hdma_cycles = 0;
+                    gb->hdma_starting = true;
                 }
             }
         }
diff --git a/Core/gb.h b/Core/gb.h
index c93aa3d..48171f8 100644
--- a/Core/gb.h
+++ b/Core/gb.h
@@ -276,6 +276,7 @@ struct GB_gameboy_internal_s {
         int16_t dma_cycles;
         bool is_dma_restarting;
         uint8_t last_opcode_read; /* Required to emulte HDMA reads from Exxx */
+        bool hdma_starting;
     );
     
     /* MBC */
diff --git a/Core/z80_cpu.c b/Core/z80_cpu.c
index 4794df5..6ff69b4 100644
--- a/Core/z80_cpu.c
+++ b/Core/z80_cpu.c
@@ -1402,4 +1402,10 @@ void GB_cpu_run(GB_gameboy_t *gb)
     else {
         GB_advance_cycles(gb, 4);
     }
+    
+    if (gb->hdma_starting) {
+        gb->hdma_starting = false;
+        gb->hdma_on = true;
+        gb->hdma_cycles = 0;
+    }
 }