diff options
Diffstat (limited to 'src/devices/bus/bbc/internal/werom.cpp')
-rw-r--r-- | src/devices/bus/bbc/internal/werom.cpp | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/src/devices/bus/bbc/internal/werom.cpp b/src/devices/bus/bbc/internal/werom.cpp new file mode 100644 index 00000000000..bc38500dee8 --- /dev/null +++ b/src/devices/bus/bbc/internal/werom.cpp @@ -0,0 +1,260 @@ +// license:BSD-3-Clause +// copyright-holders:Nigel Barnes +/********************************************************************** + + Watford Electronics 12 ROM Board + http://chrisacorns.computinghistory.org.uk/8bit_Upgrades/WE_12ROMboard.html + + Watford Electronics 13 ROM Board + http://chrisacorns.computinghistory.org.uk/8bit_Upgrades/WE_13ROMBoard.html + +**********************************************************************/ + + +#include "emu.h" +#include "werom.h" + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +DEFINE_DEVICE_TYPE(BBC_WE12ROM, bbc_we12rom_device, "bbc_we12rom", "Watford Electronics 12 ROM Board"); +DEFINE_DEVICE_TYPE(BBC_WE13ROM, bbc_we13rom_device, "bbc_we13rom", "Watford Electronics 13 ROM Board"); + + +//------------------------------------------------- +// INPUT_PORTS( werom ) +//------------------------------------------------- + +static INPUT_PORTS_START(werom) + 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_we12rom_device::device_input_ports() const +{ + return INPUT_PORTS_NAME(werom); +} + +//------------------------------------------------- +// device_add_mconfig - add device configuration +//------------------------------------------------- + +void bbc_we12rom_device::device_add_mconfig(machine_config &config) +{ + /* 12 rom sockets, 16K static ram (battery backed) */ + BBC_ROMSLOT16(config, m_rom[4], bbc_rom_devices, nullptr); + BBC_ROMSLOT16(config, m_rom[5], bbc_rom_devices, nullptr); + BBC_ROMSLOT16(config, m_rom[6], bbc_rom_devices, nullptr); + BBC_ROMSLOT16(config, m_rom[7], bbc_rom_devices, nullptr); + 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, 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); +} + +void bbc_we13rom_device::device_add_mconfig(machine_config &config) +{ + /* TODO: romslot2 is unavailable when board is fitted, replaced by socket on board */ + //config.device_remove(":romslot2"); + + /* 13 rom sockets, 16K static ram (battery backed) */ + BBC_ROMSLOT16(config, m_rom[2], bbc_rom_devices, nullptr); + BBC_ROMSLOT16(config, m_rom[4], bbc_rom_devices, nullptr); + BBC_ROMSLOT16(config, m_rom[5], bbc_rom_devices, nullptr); + BBC_ROMSLOT16(config, m_rom[6], bbc_rom_devices, nullptr); + BBC_ROMSLOT16(config, m_rom[7], bbc_rom_devices, nullptr); + 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, nullptr); + BBC_ROMSLOT16(config, m_rom[13], bbc_rom_devices, nullptr); + BBC_ROMSLOT16(config, m_rom[14], bbc_rom_devices, nullptr); + BBC_ROMSLOT16(config, m_rom[15], bbc_rom_devices, "nvram").set_fixed_ram(true); +} + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// bbc_werom_device - constructor +//------------------------------------------------- + +bbc_werom_device::bbc_werom_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock) + : device_t(mconfig, type, tag, owner, clock) + , device_bbc_internal_interface(mconfig, *this) + , m_rom(*this, "romslot%u", 0U) +{ +} + +bbc_we12rom_device::bbc_we12rom_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) + : bbc_werom_device(mconfig, BBC_WE12ROM, tag, owner, clock) + , m_wp(*this, "wp") +{ +} + +bbc_we13rom_device::bbc_we13rom_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) + : bbc_werom_device(mconfig, BBC_WE13ROM, tag, owner, clock) +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void bbc_we12rom_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)); +} + +void bbc_we13rom_device::device_start() +{ + /* move internal roms to board */ + memmove(m_region_swr->base() + 0x2c000, m_region_swr->base(), 0x10000); + memset(m_region_swr->base(), 0xff, 0x10000); + + /* register for save states */ + save_item(NAME(m_romsel)); +} + + +//************************************************************************** +// IMPLEMENTATION +//************************************************************************** + +uint8_t bbc_we12rom_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; + 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_we12rom_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; + default: + /* expansion board sockets */ + if (m_rom[m_romsel]) + { + m_rom[m_romsel]->write(offset, data); + } + /* sideways ram (if not write protected) */ + if (!m_wp->read()) + { + m_rom[14]->write(offset, data); + } + break; + } +} + + +uint8_t bbc_we13rom_device::paged_r(offs_t offset) +{ + uint8_t data = 0xff; + + switch (m_romsel) + { + case 0: case 1: 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; + 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_we13rom_device::paged_w(offs_t offset, uint8_t data) +{ + switch (m_romsel) + { + case 0: case 1: case 3: + /* motherboard rom sockets */ + if (m_mb_rom[m_romsel]) + { + m_mb_rom[m_romsel]->write(offset, data); + } + break; + default: + /* expansion board sockets */ + if (m_rom[m_romsel]) + { + m_rom[m_romsel]->write(offset, data); + } + /* sideways ram */ + m_rom[15]->write(offset, data); + break; + } +} |