diff options
Diffstat (limited to 'src/devices/bus/electron/cart/romp144.cpp')
-rw-r--r-- | src/devices/bus/electron/cart/romp144.cpp | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/src/devices/bus/electron/cart/romp144.cpp b/src/devices/bus/electron/cart/romp144.cpp new file mode 100644 index 00000000000..6e4eb96bd84 --- /dev/null +++ b/src/devices/bus/electron/cart/romp144.cpp @@ -0,0 +1,162 @@ +// license:BSD-3-Clause +// copyright-holders:Nigel Barnes +/********************************************************************** + + JAFA Systems ROMPlus-144 + +**********************************************************************/ + + +#include "emu.h" +#include "romp144.h" + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +DEFINE_DEVICE_TYPE(ELECTRON_ROMP144, electron_romp144_device, "electron_romp144", "JAFA Systems ROMPlus-144") + + +//------------------------------------------------- +// device_add_mconfig - add device configuration +//------------------------------------------------- + +void electron_romp144_device::device_add_mconfig(machine_config &config) +{ + /* rom sockets */ + GENERIC_SOCKET(config, m_romslot[0], generic_plain_slot, "electron_rom", "bin,rom"); + m_romslot[0]->set_device_load(device_image_load_delegate(&electron_romp144_device::device_image_load_rom0, this)); + GENERIC_SOCKET(config, m_romslot[1], generic_plain_slot, "electron_rom", "bin,rom"); + m_romslot[1]->set_device_load(device_image_load_delegate(&electron_romp144_device::device_image_load_rom1, this)); + GENERIC_SOCKET(config, m_romslot[2], generic_plain_slot, "electron_rom", "bin,rom"); + m_romslot[2]->set_device_load(device_image_load_delegate(&electron_romp144_device::device_image_load_rom2, this)); + GENERIC_SOCKET(config, m_romslot[3], generic_plain_slot, "electron_rom", "bin,rom"); + m_romslot[3]->set_device_load(device_image_load_delegate(&electron_romp144_device::device_image_load_rom3, this)); + GENERIC_SOCKET(config, m_romslot[4], generic_plain_slot, "electron_rom", "bin,rom"); + m_romslot[4]->set_device_load(device_image_load_delegate(&electron_romp144_device::device_image_load_rom4, this)); + GENERIC_SOCKET(config, m_romslot[5], generic_plain_slot, "electron_rom", "bin,rom"); + m_romslot[5]->set_device_load(device_image_load_delegate(&electron_romp144_device::device_image_load_rom5, this)); + GENERIC_SOCKET(config, m_romslot[6], generic_plain_slot, "electron_rom", "bin,rom"); + m_romslot[6]->set_device_load(device_image_load_delegate(&electron_romp144_device::device_image_load_rom6, this)); +} + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// electron_romp144_device - constructor +//------------------------------------------------- + +electron_romp144_device::electron_romp144_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) + : device_t(mconfig, ELECTRON_ROMP144, tag, owner, clock) + , device_electron_cart_interface(mconfig, *this) + , m_romslot(*this, "rom%u", 7) +{ +} + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void electron_romp144_device::device_start() +{ + m_rom_select = 0xff; + m_rom_latch = 0xff; + + save_item(NAME(m_rom_select)); + save_item(NAME(m_rom_latch)); +} + +//------------------------------------------------- +// read - cartridge data read +//------------------------------------------------- + +uint8_t electron_romp144_device::read(offs_t offset, int infc, int infd, int romqa, int oe, int oe2) +{ + uint8_t data = 0xff; + + if (oe) + { + if (romqa) + { + if ((m_rom_select & 0x07) == 0x00) + data = m_ram[offset & 0x3fff]; + else + data = m_romslot[(m_rom_select & 0x07) - 1]->read_rom(offset & 0x3fff); + } + else + { + if ((m_rom_select & 0x0f) == 0x08) + data = m_ram[(offset & 0x3fff) | 0x4000]; + else + data = m_rom[offset & 0x1fff]; + + /* roms selected with a read to latch */ + if ((offset & 0x3f00) == 0x3f00) + { + m_rom_latch = offset & 0x0f; + } + } + } + + return data; +} + +//------------------------------------------------- +// write - cartridge data write +//------------------------------------------------- + +void electron_romp144_device::write(offs_t offset, uint8_t data, int infc, int infd, int romqa, int oe, int oe2) +{ + if (oe) + { + if (romqa) + { + if ((m_rom_select & 0x07) == 0x00) + m_ram[offset & 0x3fff] = data; + } + else + { + if ((m_rom_select & 0x0f) == 0x08) + m_ram[(offset & 0x3fff) | 0x4000] = data; + + /* roms selected with a write to select */ + if ((offset & 0x3f00) == 0x3f00) + { + /* does the write match the read (upper RAM cannot be de-selected to protect *RSUBSTITUTE) */ + if (m_rom_latch == (offset & 0x0f) && m_rom_select != 0x08) + { + m_rom_select = m_rom_latch; + } + } + } + } +} + + +//************************************************************************** +// IMPLEMENTATION +//************************************************************************** + +image_init_result electron_romp144_device::load_rom(device_image_interface &image, generic_slot_device *slot) +{ + uint32_t size = slot->common_get_size("rom"); + + // socket accepts 8K and 16K ROM only + if (size != 0x2000 && size != 0x4000) + { + image.seterror(IMAGE_ERROR_UNSPECIFIED, "Invalid size: Only 8K/16K is supported"); + return image_init_result::FAIL; + } + + slot->rom_alloc(0x4000, GENERIC_ROM8_WIDTH, ENDIANNESS_LITTLE); + slot->common_load_rom(slot->get_rom_base(), size, "rom"); + + // mirror 8K ROMs + uint8_t *crt = slot->get_rom_base(); + if (size <= 0x2000) memcpy(crt + 0x2000, crt, 0x2000); + + return image_init_result::PASS; +} |