1 files changed, 77 insertions, 1 deletions
diff --git a/src/mame/video/galaxian.cpp b/src/mame/video/galaxian.cpp
index 95b85463c09..b54d49a5db9 100644
--- a/src/mame/video/galaxian.cpp
+++ b/src/mame/video/galaxian.cpp
@@ -1,5 +1,5 @@
 // license:BSD-3-Clause
-// copyright-holders:Aaron Giles, Couriersud
+// copyright-holders:Aaron Giles, Couriersud, Robbbert
 /***************************************************************************
 
     Galaxian-derived video hardware
@@ -1359,3 +1359,79 @@ void galaxian_state::jumpbug_extend_sprite_info(const uint8_t *base, uint8_t *sx
 						((~m_gfxbank[4] & 0x01) << 6);
 	}
 }
+
+
+
+/*************************************
+ *
+ *  Four Play extensions
+ *
+ *************************************/
+
+/* gfxbank[4] is used as a cpu bank number, and gfxbank[0] for graphics banking */ 
+WRITE8_MEMBER( galaxian_state::fourplay_rombank_w )
+{
+	m_gfxbank[4] = (m_gfxbank[4] & (2 - offset)) | (data << offset);
+
+	m_gfxbank[0] = (m_gfxbank[4] == 3);	// 1 = true, 0 = false
+
+	membank("bank1")->set_entry( m_gfxbank[4] );
+}
+
+
+
+/*************************************
+ *
+ *  Video Eight extensions
+ *
+ *************************************/
+
+void galaxian_state::videight_extend_tile_info(uint16_t *code, uint8_t *color, uint8_t attrib, uint8_t x)
+{
+	*code |= (m_gfxbank[0] << 8);
+	*color |= (m_gfxbank[4] << 3);
+}
+
+void galaxian_state::videight_extend_sprite_info(const uint8_t *base, uint8_t *sx, uint8_t *sy, uint8_t *flipx, uint8_t *flipy, uint16_t *code, uint8_t *color)
+{
+	*code |= (m_gfxbank[0] << 6);
+	*color |= (m_gfxbank[4] << 3);
+}
+
+
+/* This handles the main bankswitching for code and one-bank gfx games */
+WRITE8_MEMBER( galaxian_state::videight_rombank_w )
+{
+	uint8_t gfxbanks[] = { 0, 10, 2, 8, 1, 9, 4, 11 };
+	if (offset == 2)
+		galaxian_stars_enable_w( space, 0, data );
+	else
+	{
+		m_gfxbank[4] = (m_gfxbank[4] & (6 - offset)) | (data << ((offset + 1) >> 1));
+		galaxian_gfxbank_w (space, 0, gfxbanks[m_gfxbank[4]]);
+		membank("bank1")->set_entry( m_gfxbank[4] );
+	}
+}
+
+/* This handles those games with multiple gfx banks */
+WRITE8_MEMBER( galaxian_state::videight_gfxbank_w )
+{
+	/* Moon Cresta (mooncrgx) */
+	if (( data < 2 ) && (m_gfxbank[4] == 3))
+	{
+		uint8_t gfxbanks[] = { 8, 12, 8, 14, 8, 13, 8, 15 };
+		if (!offset) m_gfxbank[3] = (m_gfxbank[3] & 6) | data;
+		if (offset == 1) m_gfxbank[3] = (m_gfxbank[3] & 5) | (data << 1);
+		if (offset == 2) m_gfxbank[3] = (m_gfxbank[3] & 3) | (data << 2);
+		galaxian_gfxbank_w(space, 0, gfxbanks[m_gfxbank[3]]);
+	}
+
+	/* Uniwar S */
+	if (( data < 2 ) && (m_gfxbank[4] == 2) && (offset == 2))
+		galaxian_gfxbank_w( space, 0, data+2 );
+
+	/* Pisces (piscesb) */
+	if (( data < 2 ) && (m_gfxbank[4] == 6) && (offset == 2))
+		galaxian_gfxbank_w( space, 0, data+4 );
+}
+