diff options
Diffstat (limited to 'src/devices/bus/archimedes/podule/rom.cpp')
-rw-r--r-- | src/devices/bus/archimedes/podule/rom.cpp | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/src/devices/bus/archimedes/podule/rom.cpp b/src/devices/bus/archimedes/podule/rom.cpp new file mode 100644 index 00000000000..94c55746ee0 --- /dev/null +++ b/src/devices/bus/archimedes/podule/rom.cpp @@ -0,0 +1,190 @@ +// license:BSD-3-Clause +// copyright-holders:Nigel Barnes +/********************************************************************** + + Acorn AKA05 ROM Podule + + http://chrisacorns.computinghistory.org.uk/32bit_UpgradesA2G/Acorn_AKA05_ROMpodule.html + +**********************************************************************/ + +#include "emu.h" +#include "rom.h" +#include "bus/generic/slot.h" +#include "bus/generic/carts.h" +#include "bus/generic/ram.h" +#include "bus/generic/rom.h" + + +namespace { + +class arc_rom_aka05_device : + public device_t, + public device_archimedes_podule_interface +{ +public: + // construction/destruction + arc_rom_aka05_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock); + + static constexpr feature_type unemulated_features() { return feature::ROM; } + +protected: + // device-level overrides + virtual void device_start() override; + virtual void device_reset() override; + + // optional information overrides + virtual void device_add_mconfig(machine_config &config) override; + virtual const tiny_rom_entry *device_rom_region() const override; + + // device_archimedes_podule_interface overrides + virtual void ioc_map(address_map &map) override; + +private: + required_memory_region m_podule_rom; + required_device_array<generic_slot_device, 7> m_rom; + + u8 rom_r(offs_t offset); + void rom_w(offs_t offset, u8 data); + + u8 m_rom_select; + u8 m_rom_page; +}; + + +void arc_rom_aka05_device::ioc_map(address_map &map) +{ + map(0x0000, 0x1fff).rw(FUNC(arc_rom_aka05_device::rom_r), FUNC(arc_rom_aka05_device::rom_w)).umask32(0x000000ff); + map(0x2000, 0x2fff).lw8(NAME([this](u8 data) { m_rom_page = data & 0x3f; m_rom_select = (m_rom_select & 0x04) | ((data >> 6) & 0x03); })).umask32(0x000000ff); + map(0x3000, 0x37ff).lw8(NAME([this](u8 data) { m_rom_select &= ~0x04; })).umask32(0x000000ff); + map(0x3800, 0x3fff).lw8(NAME([this](u8 data) { m_rom_select |= 0x04; })).umask32(0x000000ff); +} + + +//------------------------------------------------- +// ROM( rom ) +//------------------------------------------------- + +ROM_START( rom_aka05 ) + ROM_REGION(0x20000, "podule_rom", ROMREGION_ERASEFF) + ROM_SYSTEM_BIOS(0, "2", "Second release 18-Dec-87") + ROMX_LOAD("0276,221-02_manager.bin", 0x0000, 0x4000, CRC(23ec4ddb) SHA1(e699157895433010b1ea110c78fbc80a4bc58f09), ROM_BIOS(0)) +ROM_END + +const tiny_rom_entry *arc_rom_aka05_device::device_rom_region() const +{ + return ROM_NAME( rom_aka05 ); +} + + +void arc_ram_devices(device_slot_interface &device) +{ + device.option_add("ram", GENERIC_RAM_32K_PLAIN); +} + +//------------------------------------------------- +// device_add_mconfig - add device configuration +//------------------------------------------------- + +void arc_rom_aka05_device::device_add_mconfig(machine_config &config) +{ + // rom sockets 5 x 128K + GENERIC_SOCKET(config, m_rom[0], generic_plain_slot, "bbc_rom", "bin,rom"); + GENERIC_SOCKET(config, m_rom[1], generic_plain_slot, "bbc_rom", "bin,rom"); + GENERIC_SOCKET(config, m_rom[2], generic_plain_slot, "bbc_rom", "bin,rom"); + GENERIC_SOCKET(config, m_rom[3], generic_plain_slot, "bbc_rom", "bin,rom"); + GENERIC_SOCKET(config, m_rom[4], generic_plain_slot, "bbc_rom", "bin,rom"); + + // ram sockets 2 x 32K + GENERIC_SOCKET(config, m_rom[5], arc_ram_devices, "bbc_rom", "bin,rom").set_user_loadable(false); + GENERIC_SOCKET(config, m_rom[6], arc_ram_devices, "bbc_rom", "bin,rom").set_user_loadable(false); + + SOFTWARE_LIST(config, "rom_ls").set_original("bbc_rom").set_filter("B"); +} + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// arc_rom_aka05_device - constructor +//------------------------------------------------- + +arc_rom_aka05_device::arc_rom_aka05_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock) + : device_t(mconfig, ARC_ROM_AKA05, tag, owner, clock) + , device_archimedes_podule_interface(mconfig, *this) + , m_podule_rom(*this, "podule_rom") + , m_rom(*this, "rom%u", 1U) + , m_rom_select(0) + , m_rom_page(0) +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void arc_rom_aka05_device::device_start() +{ + save_item(NAME(m_rom_select)); + save_item(NAME(m_rom_page)); +} + + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void arc_rom_aka05_device::device_reset() +{ + m_rom_select = 0x00; + m_rom_page = 0x00; +} + + +//************************************************************************** +// IMPLEMENTATION +//************************************************************************** + +u8 arc_rom_aka05_device::rom_r(offs_t offset) +{ + u8 data = 0xff; + + switch (m_rom_select) + { + case 0: + data = m_podule_rom->base()[offset | (m_rom_page << 11)]; + break; + + case 1: case 2: case 3: case 4: case 5: + data = m_rom[m_rom_select - 1]->read_rom(offset | (m_rom_page << 11)); + break; + + case 6: case 7: + data = m_rom[m_rom_select - 1]->read_ram(offset | (m_rom_page << 11)); + break; + } + + return data; +} + +void arc_rom_aka05_device::rom_w(offs_t offset, u8 data) +{ + switch (m_rom_select) + { + case 6: case 7: + m_rom[m_rom_select - 1]->write_ram(offset | (m_rom_page << 11), data); + break; + } +} + +} // anonymous namespace + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +DEFINE_DEVICE_TYPE_PRIVATE(ARC_ROM_AKA05, device_archimedes_podule_interface, arc_rom_aka05_device, "arc_rom_aka05", "Acorn AKA05 ROM Podule") |