diff options
Diffstat (limited to 'src/devices/bus/vic20/megacart.c')
-rw-r--r-- | src/devices/bus/vic20/megacart.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/src/devices/bus/vic20/megacart.c b/src/devices/bus/vic20/megacart.c new file mode 100644 index 00000000000..e92e1dbbc55 --- /dev/null +++ b/src/devices/bus/vic20/megacart.c @@ -0,0 +1,130 @@ +// license:BSD-3-Clause +// copyright-holders:Curt Coder +/********************************************************************** + + Mega-Cart cartridge emulation + +**********************************************************************/ + +#include "megacart.h" + + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +const device_type VIC20_MEGACART = &device_creator<vic20_megacart_device>; + + +//------------------------------------------------- +// MACHINE_DRIVER( vic20_megacart ) +//------------------------------------------------- + +static MACHINE_CONFIG_FRAGMENT( vic20_megacart ) + +MACHINE_CONFIG_END + + +//------------------------------------------------- +// machine_config_additions - device-specific +// machine configurations +//------------------------------------------------- + +machine_config_constructor vic20_megacart_device::device_mconfig_additions() const +{ + return MACHINE_CONFIG_NAME( vic20_megacart ); +} + + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// vic20_megacart_device - constructor +//------------------------------------------------- + +vic20_megacart_device::vic20_megacart_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) + : device_t(mconfig, VIC20_MEGACART, "Mega-Cart", tag, owner, clock, "megacart", __FILE__), + device_vic20_expansion_card_interface(mconfig, *this), + device_nvram_interface(mconfig, *this), + m_nvram_en(0) +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void vic20_megacart_device::device_start() +{ + m_nvram.allocate(0x2000); + + // state saving + save_item(NAME(m_nvram_en)); +} + + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void vic20_megacart_device::device_reset() +{ +} + + +//------------------------------------------------- +// vic20_cd_r - cartridge data read +//------------------------------------------------- + +UINT8 vic20_megacart_device::vic20_cd_r(address_space &space, offs_t offset, UINT8 data, int ram1, int ram2, int ram3, int blk1, int blk2, int blk3, int blk5, int io2, int io3) +{ + if (!ram1 || !ram2 || !ram3 || !io2 || !io3) + { + if (m_nvram_en) + { + data = m_nvram[offset & 0x1fff]; + } + } + else if (!blk1 || !blk2 || !blk3) + { + } + else if (!blk5) + { + } + + return data; +} + + +//------------------------------------------------- +// vic20_cd_w - cartridge data write +//------------------------------------------------- + +void vic20_megacart_device::vic20_cd_w(address_space &space, offs_t offset, UINT8 data, int ram1, int ram2, int ram3, int blk1, int blk2, int blk3, int blk5, int io2, int io3) +{ + if (!ram1 || !ram2 || !ram3 || !io2) + { + if (m_nvram_en) + { + m_nvram[offset & 0x1fff] = data; + } + } + else if (!blk1 || !blk2 || !blk3) + { + } + else if (!blk5) + { + } + else if (!io3) + { + if (m_nvram_en) + { + m_nvram[offset & 0x1fff] = data; + } + } +} |