diff options
Diffstat (limited to 'src/devices/bus/bbc/1mhzbus/multiform.cpp')
-rw-r--r-- | src/devices/bus/bbc/1mhzbus/multiform.cpp | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/src/devices/bus/bbc/1mhzbus/multiform.cpp b/src/devices/bus/bbc/1mhzbus/multiform.cpp new file mode 100644 index 00000000000..c3830db5d6e --- /dev/null +++ b/src/devices/bus/bbc/1mhzbus/multiform.cpp @@ -0,0 +1,195 @@ +// license:BSD-3-Clause +// copyright-holders:Nigel Barnes +/********************************************************************** + + PEDL Multiform Z80 2nd processor + + http://chrisacorns.computinghistory.org.uk/8bit_Upgrades/Technomatic_MultiformZ80.html + + TODO: + - Find utility disc, library disc, and manual + +**********************************************************************/ + + +#include "emu.h" +#include "multiform.h" +#include "softlist_dev.h" + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +DEFINE_DEVICE_TYPE(BBC_MULTIFORM, bbc_multiform_device, "bbc_multiform", "PEDL Multiform Z80") + + +//------------------------------------------------- +// ADDRESS_MAP( z80_mem ) +//------------------------------------------------- + +void bbc_multiform_device::z80_mem(address_map &map) +{ + map(0x0000, 0xffff).rw(FUNC(bbc_multiform_device::mem_r), FUNC(bbc_multiform_device::mem_w)); +} + +//------------------------------------------------- +// ADDRESS_MAP( z80_io ) +//------------------------------------------------- + +void bbc_multiform_device::z80_io(address_map &map) +{ + map.global_mask(0xff); + map(0x00, 0x00).r(m_host_latch[0], FUNC(generic_latch_8_device::read)).w(m_parasite_latch[0], FUNC(generic_latch_8_device::write)); + map(0x01, 0x01).r(m_host_latch[1], FUNC(generic_latch_8_device::read)).w(m_parasite_latch[1], FUNC(generic_latch_8_device::write)); + map(0x80, 0x80).w(FUNC(bbc_multiform_device::rom_disable_w)); +} + +//------------------------------------------------- +// ROM( multiform ) +//------------------------------------------------- + +ROM_START(multiform) + ROM_REGION(0x2000, "osm", 0) + ROM_LOAD("osmv200.rom", 0x0000, 0x2000, CRC(67ce1713) SHA1(314ee6211a7af6cab659640fbdd11f1078460f08)) + + ROM_REGION(0x4000, "exp_rom", 0) + ROM_LOAD("osmz80v137.rom", 0x0000, 0x4000, CRC(79a8de8f) SHA1(0bc06ce54ab9a2242294bbbe9ce8f07e464bb674)) +ROM_END + +//------------------------------------------------- +// device_add_mconfig - add device configuration +//------------------------------------------------- + +void bbc_multiform_device::device_add_mconfig(machine_config &config) +{ + Z80(config, m_z80, 8_MHz_XTAL / 2); + m_z80->set_addrmap(AS_PROGRAM, &bbc_multiform_device::z80_mem); + m_z80->set_addrmap(AS_IO, &bbc_multiform_device::z80_io); + m_z80->set_irq_acknowledge_callback(FUNC(bbc_multiform_device::irq_callback)); + + /* 74ls374 */ + GENERIC_LATCH_8(config, m_host_latch[0]); + GENERIC_LATCH_8(config, m_host_latch[1]); + GENERIC_LATCH_8(config, m_parasite_latch[0]); + GENERIC_LATCH_8(config, m_parasite_latch[1]); + + /* software lists */ + SOFTWARE_LIST(config, "flop_ls_z80").set_original("bbc_flop_z80"); +} + +//------------------------------------------------- +// rom_region - device-specific ROM region +//------------------------------------------------- + +const tiny_rom_entry *bbc_multiform_device::device_rom_region() const +{ + return ROM_NAME( multiform ); +} + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// bbc_multiform_device - constructor +//------------------------------------------------- + +bbc_multiform_device::bbc_multiform_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) + : device_t(mconfig, BBC_MULTIFORM, tag, owner, clock) + , device_bbc_1mhzbus_interface(mconfig, *this) + , m_z80(*this, "z80") + , m_host_latch(*this, "host_latch%u", 0U) + , m_parasite_latch(*this, "parasite_latch%u", 0U) + , m_osm(*this, "osm") + , m_rom_enabled(true) +{ +} + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void bbc_multiform_device::device_start() +{ + m_ram = std::make_unique<uint8_t[]>(0x10000); + + /* register for save states */ + save_pointer(NAME(m_ram), 0x10000); + save_item(NAME(m_rom_enabled)); +} + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void bbc_multiform_device::device_reset() +{ + m_rom_enabled = true; +} + +//************************************************************************** +// IMPLEMENTATION +//************************************************************************** + +uint8_t bbc_multiform_device::fred_r(offs_t offset) +{ + uint8_t data = 0xff; + + switch (offset) + { + case 0x00: + data = m_parasite_latch[0]->read(); + break; + case 0x01: + data = m_parasite_latch[1]->read(); + break; + } + + return data; +} + +void bbc_multiform_device::fred_w(offs_t offset, uint8_t data) +{ + switch (offset) + { + case 0x00: + m_host_latch[0]->write(data); + break; + case 0x01: + m_host_latch[1]->write(data); + break; + } +} + +READ8_MEMBER(bbc_multiform_device::mem_r) +{ + uint8_t data; + + if (m_rom_enabled && offset < 0x2000) + data = m_osm->base()[offset & 0x1fff]; + else + data = m_ram[offset]; + + return data; +} + +WRITE8_MEMBER(bbc_multiform_device::mem_w) +{ + m_ram[offset] = data; +} + +WRITE8_MEMBER(bbc_multiform_device::rom_disable_w) +{ + if (!machine().side_effects_disabled()) + m_rom_enabled = false; +} + +//------------------------------------------------- +// irq vector callback +//------------------------------------------------- + +IRQ_CALLBACK_MEMBER(bbc_multiform_device::irq_callback) +{ + return 0xfe; +} |