kinst: add eprom waitstates

Author: happppp

src/mame/rare/kinst.cpp

@@ -18,9 +18,8 @@ of the "Ultra 64" arcade games.
 - The SRAM test fails in diagnostics; this is due to the fact that the test
   relies on executing out of the cache while it tromps over (and eventually
   restores) the instructions it is executing; this will likely never be fixed.
-- Bootup sequence (the blue color fill) is too fast, which in turn causes
-  attract mode music not to play. Maybe the main CPU is running at a lower
-  clockspeed at boot (50MHz/4 seems plausible), but then, what toggles it?
+- Verify waitstates on memory access, currently it's only added for EPROMs
+  during the blue screen boot up sequence.
 
 ****************************************************************************
 
@@ -244,6 +243,7 @@ class kinst_state : public driver_device
 	uint32_t screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
 	uint32_t ide_extra_r();
 	void ide_extra_w(uint32_t data);
+	uint32_t rom_r(offs_t offset);
 
 	void vram_control_w(offs_t offset, uint32_t data, uint32_t mem_mask);
 	void sound_reset_w(offs_t offset, uint32_t data, uint32_t mem_mask);
@@ -300,7 +300,6 @@ void kinst_state::machine_start()
 	// configure fast RAM regions
 	m_maincpu->add_fastram(0x08000000, 0x087fffff, false, m_rambase2);
 	m_maincpu->add_fastram(0x00000000, 0x0007ffff, false, m_rambase);
-	m_maincpu->add_fastram(0x1fc00000, 0x1fc7ffff, true,  m_rombase);
 
 	// register for savestates
 	save_item(NAME(m_vram_control));
@@ -502,6 +501,16 @@ void kinst_state::coin_control_w(offs_t offset, uint32_t data, uint32_t mem_mask
 }
 
 
+uint32_t kinst_state::rom_r(offs_t offset)
+{
+	// add RdRdy clocks on EPROM access
+	// bootup sequence takes approx. 6 seconds, and it's not a CPU clock divider
+	m_maincpu->adjust_icount(-128);
+
+	return m_rombase[offset];
+}
+
+
 
 /*************************************
  *
@@ -524,7 +533,7 @@ void kinst_state::kinst_map(address_map &map)
 
 	map(0x10000100, 0x1000013f).rw(FUNC(kinst_state::ide_r), FUNC(kinst_state::ide_w));
 	map(0x10000170, 0x10000173).rw(FUNC(kinst_state::ide_extra_r), FUNC(kinst_state::ide_extra_w));
-	map(0x1fc00000, 0x1fc7ffff).rom().region("user1", 0);
+	map(0x1fc00000, 0x1fc7ffff).r(FUNC(kinst_state::rom_r));
 }