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// license:BSD-3-Clause
// copyright-holders:Curt Coder
/**********************************************************************
Berkeley Softworks GeoRAM emulation
Copyright MESS Team.
Visit http://mamedev.org for licensing and usage restrictions.
**********************************************************************/
#include "georam.h"
//**************************************************************************
// DEVICE DEFINITIONS
//**************************************************************************
const device_type C64_GEORAM = &device_creator<c64_georam_cartridge_device>;
//**************************************************************************
// LIVE DEVICE
//**************************************************************************
//-------------------------------------------------
// c64_georam_cartridge_device - constructor
//-------------------------------------------------
c64_georam_cartridge_device::c64_georam_cartridge_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
device_t(mconfig, C64_GEORAM, "C64 GeoRAM cartridge", tag, owner, clock, "c64_georam", __FILE__),
device_c64_expansion_card_interface(mconfig, *this),
m_ram(*this, "ram")
{
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void c64_georam_cartridge_device::device_start()
{
// allocate memory
m_ram.allocate(0x80000);
// state saving
save_item(NAME(m_bank));
}
//-------------------------------------------------
// device_reset - device-specific reset
//-------------------------------------------------
void c64_georam_cartridge_device::device_reset()
{
m_bank = 0;
}
//-------------------------------------------------
// c64_cd_r - cartridge data read
//-------------------------------------------------
UINT8 c64_georam_cartridge_device::c64_cd_r(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2)
{
if (!io1)
{
offs_t addr = (m_bank << 8) | (offset & 0xff);
data = m_ram[addr];
}
return data;
}
//-------------------------------------------------
// c64_cd_w - cartridge data write
//-------------------------------------------------
void c64_georam_cartridge_device::c64_cd_w(address_space &space, offs_t offset, UINT8 data, int sphi2, int ba, int roml, int romh, int io1, int io2)
{
if (!io1)
{
offs_t addr = (m_bank << 8) | (offset & 0xff);
m_ram[addr] = data;
}
else if (!io2)
{
if (BIT(offset, 0))
{
m_bank = ((data & 0x1f) << 6) | (m_bank & 0x3f);
}
else
{
m_bank = (m_bank & 0x7c0) | (data & 0x3f);
}
}
}
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