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// license:BSD-3-Clause
// copyright-holders:tim lindner
/***************************************************************************
coco_gmc.cpp
Code for emulating the Games Master Cartridge. A banked switched ROM
cartridge with a SN76489AN programmable sound generator.
The ROM bank switching is exactly like the circuit developed for RoboCop
and Predator.
The SN76489AN is tied to address $FF41.
Cartridge by John Linville.
***************************************************************************/
#include "emu.h"
#include "coco_gmc.h"
#include "coco_pak.h"
#include "sound/sn76496.h"
#include "speaker.h"
#define SN76489AN_TAG "gmc_psg"
//**************************************************************************
// TYPE DECLARATIONS
//**************************************************************************
namespace
{
// ======================> coco_pak_banked_device
class coco_pak_gmc_device :
public coco_pak_banked_device
{
public:
// construction/destruction
coco_pak_gmc_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock);
virtual void device_add_mconfig(machine_config &config) override;
protected:
// device-level overrides
virtual void scs_write(offs_t offset, u8 data) override;
private:
required_device<sn76489a_device> m_psg;
};
};
void coco_pak_gmc_device::device_add_mconfig(machine_config &config)
{
SPEAKER(config, "gmc_speaker").front_center();
SN76489A(config, m_psg, 4_MHz_XTAL).add_route(ALL_OUTPUTS, "gmc_speaker", 1.0);
}
//**************************************************************************
// GLOBAL VARIABLES
//**************************************************************************
DEFINE_DEVICE_TYPE_PRIVATE(COCO_PAK_GMC, device_cococart_interface, coco_pak_gmc_device, "cocopakgmc", "CoCo Games Master Cartridge")
//-------------------------------------------------
// coco_pak_device - constructor
//-------------------------------------------------
coco_pak_gmc_device::coco_pak_gmc_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
: coco_pak_banked_device(mconfig, COCO_PAK_GMC, tag, owner, clock)
, m_psg(*this, SN76489AN_TAG)
{
}
//-------------------------------------------------
// scs_write
//-------------------------------------------------
void coco_pak_gmc_device::scs_write(offs_t offset, u8 data)
{
switch(offset)
{
case 0:
/* set the bank */
coco_pak_banked_device::scs_write(offset, data);
break;
case 1:
m_psg->write(data);
break;
}
}
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