From 5fdb04640766a623f8da1c996f281bd9722dabda Mon Sep 17 00:00:00 2001
From: AJR <ajrhacker@users.noreply.github.com>
Date: Wed, 22 Aug 2018 20:51:56 -0400
Subject: [PATCH] i8155: Eliminate unnecessary memory interface for internal
 RAM (nw)

---
 src/devices/machine/i8155.cpp | 37 +++++++----------------------------
 src/devices/machine/i8155.h   | 10 ++++------
 src/mame/drivers/cp1.cpp      |  6 +++---
 3 files changed, 14 insertions(+), 39 deletions(-)

diff --git a/src/devices/machine/i8155.cpp b/src/devices/machine/i8155.cpp
index 8d7adef7760..779874a244d 100644
--- a/src/devices/machine/i8155.cpp
+++ b/src/devices/machine/i8155.cpp
@@ -105,18 +105,6 @@ enum
 
 
 
-//**************************************************************************
-//  GLOBAL VARIABLES
-//**************************************************************************
-
-// default address map
-void i8155_device::i8155(address_map &map)
-{
-	map(0x00, 0xff).ram();
-}
-
-
-
 //**************************************************************************
 //  INLINE HELPERS
 //**************************************************************************
@@ -272,7 +260,6 @@ i8155_device::i8155_device(const machine_config &mconfig, const char *tag, devic
 
 i8155_device::i8155_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock)
 	: device_t(mconfig, type, tag, owner, clock),
-		device_memory_interface(mconfig, *this),
 		m_in_pa_cb(*this),
 		m_in_pb_cb(*this),
 		m_in_pc_cb(*this),
@@ -286,8 +273,7 @@ i8155_device::i8155_device(const machine_config &mconfig, device_type type, cons
 		m_count_loaded(0),
 		m_counter(0),
 		m_count_extra(false),
-		m_to(0),
-		m_space_config("ram", ENDIANNESS_LITTLE, 8, 8, 0, address_map_constructor(), address_map_constructor(FUNC(i8155_device::i8155), this))
+		m_to(0)
 {
 }
 
@@ -317,6 +303,9 @@ void i8155_device::device_start()
 	m_out_pc_cb.resolve_safe();
 	m_out_to_cb.resolve_safe();
 
+	// allocate RAM
+	m_ram = make_unique_clear<uint8_t[]>(256);
+
 	// allocate timers
 	m_timer = timer_alloc();
 
@@ -326,6 +315,7 @@ void i8155_device::device_start()
 	save_item(NAME(m_command));
 	save_item(NAME(m_status));
 	save_item(NAME(m_output));
+	save_pointer(NAME(m_ram), 256);
 	save_item(NAME(m_count_length));
 	save_item(NAME(m_count_loaded));
 	save_item(NAME(m_count_extra));
@@ -412,19 +402,6 @@ void i8155_device::device_timer(emu_timer &timer, device_timer_id id, int param,
 }
 
 
-//-------------------------------------------------
-//  memory_space_config - return a description of
-//  any address spaces owned by this device
-//-------------------------------------------------
-
-device_memory_interface::space_config_vector i8155_device::memory_space_config() const
-{
-	return space_config_vector {
-		std::make_pair(0, &m_space_config)
-	};
-}
-
-
 //-------------------------------------------------
 //  io_r - register read
 //-------------------------------------------------
@@ -574,7 +551,7 @@ WRITE8_MEMBER( i8155_device::io_w )
 
 READ8_MEMBER( i8155_device::memory_r )
 {
-	return this->space().read_byte(offset);
+	return m_ram[offset & 0xff];
 }
 
 
@@ -584,7 +561,7 @@ READ8_MEMBER( i8155_device::memory_r )
 
 WRITE8_MEMBER( i8155_device::memory_w )
 {
-	this->space().write_byte(offset, data);
+	m_ram[offset & 0xff] = data;
 }
 
 
diff --git a/src/devices/machine/i8155.h b/src/devices/machine/i8155.h
index 19117e06cea..a17692211e6 100644
--- a/src/devices/machine/i8155.h
+++ b/src/devices/machine/i8155.h
@@ -41,8 +41,7 @@
 
 // ======================> i8155_device
 
-class i8155_device :    public device_t,
-						public device_memory_interface
+class i8155_device : public device_t
 {
 public:
 	// construction/destruction
@@ -74,8 +73,6 @@ protected:
 	virtual void device_reset() override;
 	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
-	virtual space_config_vector memory_space_config() const override;
-
 private:
 	devcb_read8        m_in_pa_cb;
 	devcb_read8        m_in_pb_cb;
@@ -97,6 +94,9 @@ private:
 	uint8_t m_status;           // status register
 	uint8_t m_output[3];        // output latches
 
+	// RAM
+	std::unique_ptr<uint8_t[]> m_ram;
+
 	// counter
 	uint16_t m_count_length;    // count length register (assigned)
 	uint16_t m_count_loaded;    // count length register (loaded)
@@ -118,8 +118,6 @@ private:
 	inline void write_port(int port, uint8_t data);
 
 	void register_w(int offset, uint8_t data);
-
-	void i8155(address_map &map);
 };
 
 
diff --git a/src/mame/drivers/cp1.cpp b/src/mame/drivers/cp1.cpp
index ff9532ff477..c94ab232131 100644
--- a/src/mame/drivers/cp1.cpp
+++ b/src/mame/drivers/cp1.cpp
@@ -244,7 +244,7 @@ void cp1_state::machine_reset()
 
 QUICKLOAD_LOAD_MEMBER( cp1_state, quickload )
 {
-	uint8_t *dest = (uint8_t*)m_i8155->space().get_read_ptr(0);
+	address_space &space = machine().dummy_space();
 	char line[0x10];
 	int addr = 0;
 	while (image.fgets(line, 10) && addr < 0x100)
@@ -252,8 +252,8 @@ QUICKLOAD_LOAD_MEMBER( cp1_state, quickload )
 		int op = 0, arg = 0;
 		if (sscanf(line, "%d.%d", &op, &arg) == 2)
 		{
-			dest[addr++] = op;
-			dest[addr++] = arg;
+			m_i8155->memory_w(space, addr++, op);
+			m_i8155->memory_w(space, addr++, arg);
 		}
 		else
 		{