// license:BSD-3-Clause // copyright-holders:Nigel Barnes /********************************************************************** Watford Electronics ROM/RAM Board http://chrisacorns.computinghistory.org.uk/8bit_Upgrades/WE_RAMROMBoard.html **********************************************************************/ #include "emu.h" #include "weromram.h" //************************************************************************** // DEVICE DEFINITIONS //************************************************************************** DEFINE_DEVICE_TYPE(BBC_WEROMRAM, bbc_weromram_device, "bbc_weromram", "Watford Electronics ROM/RAM Board"); //------------------------------------------------- // device_add_mconfig - add device configuration //------------------------------------------------- void bbc_weromram_device::device_add_mconfig(machine_config &config) { /* 3 rom sockets, 64K dynamic ram, 16K static ram (battery backed) */ BBC_ROMSLOT16(config, m_rom[0], bbc_rom_devices, "ram").set_fixed_ram(true); BBC_ROMSLOT16(config, m_rom[1], bbc_rom_devices, "ram").set_fixed_ram(true); BBC_ROMSLOT16(config, m_rom[2], bbc_rom_devices, "ram").set_fixed_ram(true); BBC_ROMSLOT16(config, m_rom[3], bbc_rom_devices, "ram").set_fixed_ram(true); 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[12], bbc_rom_devices, nullptr); BBC_ROMSLOT16(config, m_rom[13], bbc_rom_devices, nullptr); BBC_ROMSLOT16(config, m_rom[14], bbc_rom_devices, "nvram").set_fixed_ram(true); BBC_ROMSLOT16(config, m_rom[15], bbc_rom_devices, nullptr); } //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // bbc_weromram_device - constructor //------------------------------------------------- bbc_weromram_device::bbc_weromram_device(const machine_config &mconfig, const char *tag, device_t *owner, const XTAL &clock) : device_t(mconfig, BBC_WEROMRAM, tag, owner, clock) , device_bbc_internal_interface(mconfig, *this) , m_rom(*this, "romslot%u", 0U) { } //------------------------------------------------- // device_start - device-specific startup //------------------------------------------------- void bbc_weromram_device::device_start() { /* move internal roms to board */ memmove(m_region_swr->base() + 0x2c000, m_region_swr->base(), 0xc000); memmove(m_region_swr->base() + 0x3c000, m_region_swr->base() + 0xc000, 0x4000); memset(m_region_swr->base(), 0xff, 0x10000); /* register for save states */ save_item(NAME(m_romsel)); save_item(NAME(m_ramsel)); } //************************************************************************** // IMPLEMENTATION //************************************************************************** uint8_t bbc_weromram_device::paged_r(offs_t offset) { uint8_t data = 0xff; switch (m_romsel) { case 8: case 9: case 10: case 11: /* motherboard rom sockets 0-3 are re-assigned to 8-11 */ if (m_mb_rom[m_romsel & 0x03] && m_mb_rom[m_romsel & 0x03]->present()) { data = m_mb_rom[m_romsel & 0x03]->read(offset); } else { data = m_region_swr->base()[offset + (m_romsel << 14) - 0x20000]; } break; default: /* expansion board 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; } return data; } void bbc_weromram_device::paged_w(offs_t offset, uint8_t data) { switch (m_romsel) { case 8: case 9: case 10: case 11: /* motherboard rom sockets 0-3 are re-assigned to 8-11 */ if (m_mb_rom[m_romsel & 0x03]) { m_mb_rom[m_romsel & 0x03]->write(offset, data); } break; } /* expansion board sockets */ if (m_rom[m_ramsel]) { m_rom[m_ramsel]->write(offset, data); } }