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// license:BSD-3-Clause
// copyright-holders:Fabio Priuli
/***********************************************************************************************************
GCE Vectrex cart emulation
TODO:
- better understand how much SRAM is expected to be present by the homebrew using
this cart type and use a RAM array instead of the ROM region for writes
***********************************************************************************************************/
#include "emu.h"
#include "rom.h"
//-------------------------------------------------
// vectrex_rom_device - constructor
//-------------------------------------------------
const device_type VECTREX_ROM_STD = &device_creator<vectrex_rom_device>;
const device_type VECTREX_ROM_64K = &device_creator<vectrex_rom64k_device>;
const device_type VECTREX_ROM_SRAM = &device_creator<vectrex_sram_device>;
vectrex_rom_device::vectrex_rom_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock, const char *shortname, const char *source)
: device_t(mconfig, type, name, tag, owner, clock, shortname, source),
device_vectrex_cart_interface(mconfig, *this)
{
}
vectrex_rom_device::vectrex_rom_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: device_t(mconfig, VECTREX_ROM_STD, "Vectrex Standard Carts", tag, owner, clock, "vectrex_rom", __FILE__),
device_vectrex_cart_interface(mconfig, *this)
{
}
vectrex_rom64k_device::vectrex_rom64k_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: vectrex_rom_device(mconfig, VECTREX_ROM_64K, "Vectrex Carts w/ Bankswitch", tag, owner, clock, "vectrex_64k", __FILE__), m_bank(0)
{
}
vectrex_sram_device::vectrex_sram_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: vectrex_rom_device(mconfig, VECTREX_ROM_SRAM, "Vectrex Carts w/ SRAM", tag, owner, clock, "vectrex_sram", __FILE__)
{
}
void vectrex_rom64k_device::device_start()
{
save_item(NAME(m_bank));
}
void vectrex_rom64k_device::device_reset()
{
m_bank = 0;
}
/*-------------------------------------------------
mapper specific handlers
-------------------------------------------------*/
READ8_MEMBER(vectrex_rom_device::read_rom)
{
if (offset < m_rom_size)
return m_rom[offset];
else
return 0xff;
}
READ8_MEMBER(vectrex_rom64k_device::read_rom)
{
return m_rom[(offset + m_bank * 0x8000) & (m_rom_size - 1)];
}
WRITE8_MEMBER(vectrex_rom64k_device::write_bank)
{
m_bank = data >> 6;
}
WRITE8_MEMBER(vectrex_sram_device::write_ram)
{
m_rom[offset & (m_rom_size - 1)] = data;
}
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