// license:BSD-3-Clause // copyright-holders:Nigel Barnes /********************************************************************** Solidisk Twomeg 128K Shadow and Sideways ROM/RAM board **********************************************************************/ #include "emu.h" #include "stl2m128.h" //************************************************************************** // DEVICE DEFINITIONS //************************************************************************** DEFINE_DEVICE_TYPE(BBC_STL2M128, bbc_stl2m128_device, "bbc_stl2m128", "Solidisk Twomeg 128K RAM/ROM Expansion"); //------------------------------------------------- // INPUT_PORTS( stl2m128 ) //------------------------------------------------- static INPUT_PORTS_START(stl2m128) PORT_START("wp") PORT_CONFNAME(0x01, 0x00, "Write Protect Sideways RAM") PORT_CONFSETTING(0x00, DEF_STR(No)) PORT_CONFSETTING(0x01, DEF_STR(Yes)) INPUT_PORTS_END //------------------------------------------------- // input_ports - device-specific input ports //------------------------------------------------- ioport_constructor bbc_stl2m128_device::device_input_ports() const { return INPUT_PORTS_NAME(stl2m128); } //------------------------------------------------- // ROM( stl2m128 ) //------------------------------------------------- ROM_START(stl2m128) ROM_REGION(0x4000, "rom", ROMREGION_ERASEFF) // ROM image usually distributed on floppy, to load into RAM ROM_LOAD("manger128-1.00.rom", 0x0000, 0x102a, CRC(dbe84acb) SHA1(d170632b88d0ab276a919b0076dca305094a39b2)) ROM_END //------------------------------------------------- // device_add_mconfig - add device configuration //------------------------------------------------- void bbc_stl2m128_device::device_add_mconfig(machine_config &config) { BBC_ROMSLOT16(config, m_rom[4], bbc_rom_devices, "ram").set_fixed_ram(true); BBC_ROMSLOT16(config, m_rom[5], bbc_rom_devices, "ram").set_fixed_ram(true); BBC_ROMSLOT16(config, m_rom[6], bbc_rom_devices, "ram").set_fixed_ram(true); BBC_ROMSLOT16(config, m_rom[7], bbc_rom_devices, "ram").set_fixed_ram(true); BBC_ROMSLOT16(config, m_rom[8], bbc_rom_devices, nullptr); BBC_ROMSLOT16(config, m_rom[9], bbc_rom_devices, nullptr); BBC_ROMSLOT16(config, m_rom[10], bbc_rom_devices, nullptr); BBC_ROMSLOT16(config, m_rom[11], bbc_rom_devices, nullptr); BBC_ROMSLOT16(config, m_rom[12], bbc_rom_devices, "ram").set_fixed_ram(true); BBC_ROMSLOT16(config, m_rom[13], bbc_rom_devices, "ram").set_fixed_ram(true); BBC_ROMSLOT16(config, m_rom[14], bbc_rom_devices, "ram").set_fixed_ram(true); BBC_ROMSLOT16(config, m_rom[15], bbc_rom_devices, "ram").set_fixed_ram(true); } //------------------------------------------------- // rom_region - device-specific ROM region //------------------------------------------------- const tiny_rom_entry *bbc_stl2m128_device::device_rom_region() const { return ROM_NAME(stl2m128); } //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // bbc_stl2m128_device - constructor //------------------------------------------------- bbc_stl2m128_device::bbc_stl2m128_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : device_t(mconfig, BBC_STL2M128, tag, owner, clock) , device_bbc_internal_interface(mconfig, *this) , m_rom(*this, "romslot%u", 0U) , m_wp(*this, "wp") { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void bbc_stl2m128_device::device_start() { m_ram = std::make_unique(0x20000); /* copy rom image into ram bank c */ memcpy(&m_ram[0x10000], memregion("rom")->base(), 0x4000); /* move internal roms to board */ memmove(m_region_swr->base() + 0x20000, m_region_swr->base(), 0x10000); memset(m_region_swr->base(), 0xff, 0x10000); /* register for save states */ save_pointer(NAME(m_ram), 0x20000); save_item(NAME(m_romsel)); save_item(NAME(m_shadow)); } //************************************************************************** // IMPLEMENTATION //************************************************************************** void bbc_stl2m128_device::romsel_w(offs_t offset, uint8_t data) { switch (offset & 0x0c) { case 0x00: m_romsel = data & 0x0f; break; case 0x04: m_shadow = data; break; } } uint8_t bbc_stl2m128_device::ram_r(offs_t offset) { uint8_t data = 0xff; if (BIT(m_shadow, 7) && offset >= 0x2000) { if (BIT(m_shadow, 1)) { /* banks E/F */ data = m_ram[offset | 0x18000]; } else { /* banks C/D */ data = m_ram[offset | 0x10000]; } } else { data = m_mb_ram->pointer()[offset]; } return data; } void bbc_stl2m128_device::ram_w(offs_t offset, uint8_t data) { if (BIT(m_shadow, 7) && offset >= 0x2000) { if (BIT(m_shadow, 1)) { /* banks E/F */ m_ram[offset | 0x18000] = data; } else { /* banks C/D */ m_ram[offset | 0x10000] = data; } } else { m_mb_ram->pointer()[offset] = data; } } uint8_t bbc_stl2m128_device::paged_r(offs_t offset) { uint8_t data = 0xff; switch (m_romsel) { case 0: case 1: case 2: case 3: /* motherboard rom sockets */ if (m_mb_rom[m_romsel] && m_mb_rom[m_romsel]->present()) { data = m_mb_rom[m_romsel]->read(offset); } else { data = m_region_swr->base()[offset + (m_romsel << 14)]; } break; case 8: case 9: case 10: case 11: /* expansion board rom sockets */ if (m_rom[m_romsel] && m_rom[m_romsel]->present()) { data = m_rom[m_romsel]->read(offset); } else { data = m_region_swr->base()[offset + (m_romsel << 14)]; } break; case 4: case 5: case 6: case 7: case 12: case 13: case 14: case 15: /* expansion board ram sockets */ data = m_ram[offset | ((m_romsel & 0x03) << 14) | ((m_romsel & 0x08) << 13)]; break; } return data; } void bbc_stl2m128_device::paged_w(offs_t offset, uint8_t data) { switch (m_romsel) { case 0: case 1: case 2: case 3: /* motherboard rom sockets */ if (m_mb_rom[m_romsel]) { m_mb_rom[m_romsel]->write(offset, data); } break; case 8: case 9: case 10: case 11: /* expansion board rom sockets */ if (m_rom[m_romsel]) { m_rom[m_romsel]->write(offset, data); } break; case 4: case 5: case 6: case 7: case 12: case 13: case 14: case 15: /* expansion board ram sockets */ if (!m_wp->read()) { m_ram[offset | ((m_romsel & 0x03) << 14) | ((m_romsel & 0x08) << 13)] = data; } break; } }