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/**********************************************************************
COMX-35 RAM Card emulation
Copyright MESS Team.
Visit http://mamedev.org for licensing and usage restrictions.
**********************************************************************/
#include "comx_ram.h"
//**************************************************************************
// MACROS/CONSTANTS
//**************************************************************************
#define RAM_SIZE 0x8000
//**************************************************************************
// DEVICE DEFINITIONS
//**************************************************************************
const device_type COMX_RAM = &device_creator<comx_ram_device>;
//**************************************************************************
// LIVE DEVICE
//**************************************************************************
//-------------------------------------------------
// comx_ram_device - constructor
//-------------------------------------------------
comx_ram_device::comx_ram_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
device_t(mconfig, COMX_RAM, "COMX-35 RAM Card", tag, owner, clock),
device_comx_expansion_card_interface(mconfig, *this)
{
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void comx_ram_device::device_start()
{
m_ram = auto_alloc_array(machine(), UINT8, RAM_SIZE);
// state saving
save_pointer(NAME(m_ram), RAM_SIZE);
}
//-------------------------------------------------
// device_reset - device-specific reset
//-------------------------------------------------
void comx_ram_device::device_reset()
{
}
//-------------------------------------------------
// comx_mrd_r - memory read
//-------------------------------------------------
UINT8 comx_ram_device::comx_mrd_r(address_space &space, offs_t offset, int *extrom)
{
UINT8 data = 0;
if (offset >= 0xc000 && offset < 0xd000)
{
data = m_ram[(m_ram_bank << 12) | (offset & 0xfff)];
}
return data;
}
//-------------------------------------------------
// comx_mwr_w - memory write
//-------------------------------------------------
void comx_ram_device::comx_mwr_w(address_space &space, offs_t offset, UINT8 data)
{
if (offset >= 0xc000 && offset < 0xd000)
{
m_ram[(m_ram_bank << 12) | (offset & 0xfff)] = data;
}
}
//-------------------------------------------------
// comx_io_w - I/O write
//-------------------------------------------------
void comx_ram_device::comx_io_w(address_space &space, offs_t offset, UINT8 data)
{
if (offset == 1)
{
m_ram_bank = (data >> 4) & 0x03;
}
}
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