diff options
Diffstat (limited to 'src/devices/bus/bbc/internal/peartree.cpp')
-rw-r--r-- | src/devices/bus/bbc/internal/peartree.cpp | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/src/devices/bus/bbc/internal/peartree.cpp b/src/devices/bus/bbc/internal/peartree.cpp new file mode 100644 index 00000000000..49281731097 --- /dev/null +++ b/src/devices/bus/bbc/internal/peartree.cpp @@ -0,0 +1,295 @@ +// license:BSD-3-Clause +// copyright-holders:Nigel Barnes +/********************************************************************** + + Peartree MRxx00 ROM/RAM Boards + + http://chrisacorns.computinghistory.org.uk/8bit_Upgrades/Peartree_ROMExpansion.html + +**********************************************************************/ + + +#include "emu.h" +#include "peartree.h" + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +DEFINE_DEVICE_TYPE(BBC_MR3000, bbc_mr3000_device, "bbc_mr3000", "Peartree MR3000 ROM Board"); +DEFINE_DEVICE_TYPE(BBC_MR4200, bbc_mr4200_device, "bbc_mr4200", "Peartree MR4200 RAM Board"); +DEFINE_DEVICE_TYPE(BBC_MR4300, bbc_mr4300_device, "bbc_mr4300", "Peartree MR4300 ROM/RAM Board"); +DEFINE_DEVICE_TYPE(BBC_MR4800, bbc_mr4800_device, "bbc_mr4800", "Peartree MR4800 RAM Board"); + + +//------------------------------------------------- +// INPUT_PORTS( peartree ) +//------------------------------------------------- + +static INPUT_PORTS_START(peartree) + 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_mr4200_device::device_input_ports() const +{ + return INPUT_PORTS_NAME(peartree); +} + +ioport_constructor bbc_mr4300_device::device_input_ports() const +{ + return INPUT_PORTS_NAME(peartree); +} + + +//------------------------------------------------- +// device_add_mconfig - add device configuration +//------------------------------------------------- + +void bbc_mr3000_device::device_add_mconfig(machine_config &config) +{ + /* 4 rom sockets */ + 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, nullptr); +} + +void bbc_mr4200_device::device_add_mconfig(machine_config &config) +{ + /* 32K static ram */ + BBC_ROMSLOT16(config, m_rom[13], bbc_rom_devices, "ram").set_fixed_ram(true); + BBC_ROMSLOT16(config, m_rom[15], bbc_rom_devices, "ram").set_fixed_ram(true); +} + +void bbc_mr4300_device::device_add_mconfig(machine_config &config) +{ + /* 3 rom sockets, 32K static ram */ + BBC_ROMSLOT16(config, m_rom[9], bbc_rom_devices, nullptr); + BBC_ROMSLOT16(config, m_rom[11], bbc_rom_devices, nullptr); + BBC_ROMSLOT16(config, m_rom[13], bbc_rom_devices, nullptr); + 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); +} + +void bbc_mr4800_device::device_add_mconfig(machine_config &config) +{ + /* 128K static ram (battery backed) */ + BBC_ROMSLOT16(config, m_rom[8], bbc_rom_devices, "nvram").set_fixed_ram(true); + BBC_ROMSLOT16(config, m_rom[9], bbc_rom_devices, "nvram").set_fixed_ram(true); + BBC_ROMSLOT16(config, m_rom[10], bbc_rom_devices, "nvram").set_fixed_ram(true); + BBC_ROMSLOT16(config, m_rom[11], bbc_rom_devices, "nvram").set_fixed_ram(true); + BBC_ROMSLOT16(config, m_rom[12], bbc_rom_devices, "nvram").set_fixed_ram(true); + BBC_ROMSLOT16(config, m_rom[13], bbc_rom_devices, "nvram").set_fixed_ram(true); + BBC_ROMSLOT16(config, m_rom[14], bbc_rom_devices, "nvram").set_fixed_ram(true); + BBC_ROMSLOT16(config, m_rom[15], bbc_rom_devices, "nvram").set_fixed_ram(true); +} + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// bbc_mr3000_device - constructor +//------------------------------------------------- + +bbc_mr3000_device::bbc_mr3000_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_mr3000_device::bbc_mr3000_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) + : bbc_mr3000_device(mconfig, BBC_MR3000, tag, owner, clock) +{ +} + +bbc_mr4200_device::bbc_mr4200_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) + : bbc_mr3000_device(mconfig, BBC_MR4200, tag, owner, clock) + , m_wp(*this, "wp") +{ +} + +//------------------------------------------------- +// bbc_mr4300_device - constructor +//------------------------------------------------- + +bbc_mr4300_device::bbc_mr4300_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) + , m_wp(*this, "wp") +{ +} + +bbc_mr4300_device::bbc_mr4300_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) + : bbc_mr4300_device(mconfig, BBC_MR4300, tag, owner, clock) +{ +} + +bbc_mr4800_device::bbc_mr4800_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) + : bbc_mr4300_device(mconfig, BBC_MR4800, tag, owner, clock) +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void bbc_mr3000_device::device_start() +{ + /* register for save states */ + save_item(NAME(m_romsel)); +} + +void bbc_mr4300_device::device_start() +{ + /* register for save states */ + save_item(NAME(m_romsel)); +} + + +//************************************************************************** +// IMPLEMENTATION +//************************************************************************** + +uint8_t bbc_mr3000_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; + case 12: case 13: case 14: case 15: + /* 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_mr3000_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; + case 12: case 13: case 14: case 15: + /* expansion board sockets */ + if (m_rom[m_romsel]) + { + m_rom[m_romsel]->write(offset, data); + } + break; + } +} + + +void bbc_mr4200_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; + case 12: case 13: case 14: case 15: + /* expansion board sockets (if not write protected) */ + if (m_rom[m_romsel] && !m_wp->read()) + { + m_rom[m_romsel]->write(offset, data); + } + break; + } +} + + +uint8_t bbc_mr4300_device::paged_r(offs_t offset) +{ + uint8_t data = 0xff; + + switch (m_romsel) + { + case 4: case 5: case 6: case 7: + /* motherboard rom sockets 0-3 are re-assigned to 4-7 */ + 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) - 0x10000]; + } + break; + case 8: case 9: case 10: case 11: case 12: case 13: case 14: case 15: + /* 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_mr4300_device::paged_w(offs_t offset, uint8_t data) +{ + switch (m_romsel) + { + case 4: case 5: case 6: case 7: + /* motherboard rom sockets 0-3 are re-assigned to 4-7 */ + if (m_mb_rom[m_romsel & 0x03]) + { + m_mb_rom[m_romsel & 0x03]->write(offset, data); + } + break; + case 8: case 9: case 10: case 11: case 12: case 13: case 14: case 15: + /* expansion board sockets (if not write protected) */ + if (m_rom[m_romsel] && !m_wp->read()) + { + m_rom[m_romsel]->write(offset, data); + } + break; + } +} |