From 371e87b6e21e6a8202487561c1f7c5af2b38a69b Mon Sep 17 00:00:00 2001
From: AJR <ajrhacker@users.noreply.github.com>
Date: Tue, 5 Sep 2017 09:53:31 -0400
Subject: [PATCH] bombjack: Soundlatch modernization (nw)

---
 src/mame/drivers/bombjack.cpp | 29 +++++++++------------------
 src/mame/includes/bombjack.h  | 37 +++++++++++++++++++----------------
 2 files changed, 29 insertions(+), 37 deletions(-)

diff --git a/src/mame/drivers/bombjack.cpp b/src/mame/drivers/bombjack.cpp
index fe15cb6b990..db11f6e322b 100644
--- a/src/mame/drivers/bombjack.cpp
+++ b/src/mame/drivers/bombjack.cpp
@@ -106,23 +106,13 @@ Dip Locations and factory settings verified with manual
 #include "speaker.h"
 
 
-TIMER_CALLBACK_MEMBER(bombjack_state::soundlatch_callback)
+READ8_MEMBER(bombjack_state::soundlatch_read_and_clear)
 {
-	m_latch = param;
-}
-
-WRITE8_MEMBER(bombjack_state::bombjack_soundlatch_w)
-{
-	/* make all the CPUs synchronize, and only AFTER that write the new command to the latch */
-	machine().scheduler().synchronize(timer_expired_delegate(FUNC(bombjack_state::soundlatch_callback),this), data);
-}
-
-READ8_MEMBER(bombjack_state::bombjack_soundlatch_r)
-{
-	int res;
-
-	res = m_latch;
-	m_latch = 0;
+	// An extra flip-flop is used to clear the LS273 after reading it through a LS245
+	// (this flip-flop is then cleared in sync with the sound CPU clock)
+	uint8_t res = m_soundlatch->read(space, 0);
+	if (!machine().side_effect_disabled())
+		m_soundlatch->clear_w(space, 0, 0);
 	return res;
 }
 
@@ -155,14 +145,14 @@ static ADDRESS_MAP_START( main_map, AS_PROGRAM, 8, bombjack_state )
 	AM_RANGE(0xb004, 0xb004) AM_READ_PORT("DSW1")
 	AM_RANGE(0xb004, 0xb004) AM_WRITE(bombjack_flipscreen_w)
 	AM_RANGE(0xb005, 0xb005) AM_READ_PORT("DSW2")
-	AM_RANGE(0xb800, 0xb800) AM_WRITE(bombjack_soundlatch_w)
+	AM_RANGE(0xb800, 0xb800) AM_DEVWRITE("soundlatch", generic_latch_8_device, write)
 	AM_RANGE(0xc000, 0xdfff) AM_ROM
 ADDRESS_MAP_END
 
 static ADDRESS_MAP_START( audio_map, AS_PROGRAM, 8, bombjack_state )
 	AM_RANGE(0x0000, 0x1fff) AM_ROM
 	AM_RANGE(0x4000, 0x43ff) AM_RAM
-	AM_RANGE(0x6000, 0x6000) AM_READ(bombjack_soundlatch_r)
+	AM_RANGE(0x6000, 0x6000) AM_READ(soundlatch_read_and_clear)
 ADDRESS_MAP_END
 
 static ADDRESS_MAP_START( audio_io_map, AS_IO, 8, bombjack_state )
@@ -336,14 +326,12 @@ GFXDECODE_END
 
 void bombjack_state::machine_start()
 {
-	save_item(NAME(m_latch));
 	save_item(NAME(m_background_image));
 }
 
 
 void bombjack_state::machine_reset()
 {
-	m_latch = 0;
 	m_background_image = 0;
 }
 
@@ -366,6 +354,7 @@ static MACHINE_CONFIG_START( bombjack )
 	MCFG_CPU_IO_MAP(audio_io_map)
 	MCFG_CPU_VBLANK_INT_DRIVER("screen", bombjack_state,  nmi_line_pulse)
 
+	MCFG_GENERIC_LATCH_8_ADD("soundlatch")
 
 	/* video hardware */
 	MCFG_SCREEN_ADD("screen", RASTER)
diff --git a/src/mame/includes/bombjack.h b/src/mame/includes/bombjack.h
index 9432c5fd09a..fb3d2d08fe4 100644
--- a/src/mame/includes/bombjack.h
+++ b/src/mame/includes/bombjack.h
@@ -6,6 +6,8 @@
 
 *************************************************************************/
 
+#include "machine/gen_latch.h"
+
 class bombjack_state : public driver_device
 {
 public:
@@ -16,24 +18,10 @@ public:
 		m_spriteram(*this, "spriteram"),
 		m_maincpu(*this, "maincpu"),
 		m_gfxdecode(*this, "gfxdecode"),
-		m_palette(*this, "palette") { }
+		m_palette(*this, "palette"),
+		m_soundlatch(*this, "soundlatch") { }
 
-	/* memory pointers */
-	required_shared_ptr<uint8_t> m_videoram;
-	required_shared_ptr<uint8_t> m_colorram;
-	required_shared_ptr<uint8_t> m_spriteram;
-
-	/* video-related */
-	tilemap_t   *m_fg_tilemap;
-	tilemap_t   *m_bg_tilemap;
-	uint8_t       m_background_image;
-
-	/* sound-related */
-	uint8_t       m_latch;
-
-	uint8_t       m_nmi_mask;
-	DECLARE_WRITE8_MEMBER(bombjack_soundlatch_w);
-	DECLARE_READ8_MEMBER(bombjack_soundlatch_r);
+	DECLARE_READ8_MEMBER(soundlatch_read_and_clear);
 	DECLARE_WRITE8_MEMBER(irq_mask_w);
 	DECLARE_WRITE8_MEMBER(bombjack_videoram_w);
 	DECLARE_WRITE8_MEMBER(bombjack_colorram_w);
@@ -48,7 +36,22 @@ public:
 	INTERRUPT_GEN_MEMBER(vblank_irq);
 	TIMER_CALLBACK_MEMBER(soundlatch_callback);
 	void draw_sprites( bitmap_ind16 &bitmap, const rectangle &cliprect );
+
+private:
+	/* memory pointers */
+	required_shared_ptr<uint8_t> m_videoram;
+	required_shared_ptr<uint8_t> m_colorram;
+	required_shared_ptr<uint8_t> m_spriteram;
+
+	/* video-related */
+	tilemap_t   *m_fg_tilemap;
+	tilemap_t   *m_bg_tilemap;
+	uint8_t       m_background_image;
+
+	uint8_t       m_nmi_mask;
+
 	required_device<cpu_device> m_maincpu;
 	required_device<gfxdecode_device> m_gfxdecode;
 	required_device<palette_device> m_palette;
+	required_device<generic_latch_8_device> m_soundlatch;
 };