diff options
Diffstat (limited to 'src/devices/bus/electron/plus2.cpp')
-rw-r--r-- | src/devices/bus/electron/plus2.cpp | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/src/devices/bus/electron/plus2.cpp b/src/devices/bus/electron/plus2.cpp new file mode 100644 index 00000000000..040ec58eb35 --- /dev/null +++ b/src/devices/bus/electron/plus2.cpp @@ -0,0 +1,236 @@ +// license:BSD-3-Clause +// copyright-holders:Nigel Barnes +/********************************************************************** + + Slogger Plus 2 + + The Plus 2 interface from Slogger has been designed to compliment + the Slogger Rombox Plus and Acorn Plus 1 by offering further + expansion capabilities. This has been achieved by providing two + extra cartridge slots, three ROM sockets and connections for a + Usr Port and even further expansion via two expansion points. + +**********************************************************************/ + + +#include "emu.h" +#include "plus2.h" + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +DEFINE_DEVICE_TYPE(ELECTRON_PLUS2, electron_plus2_device, "electron_plus2", "Slogger Plus 2 Expansion") + + + +//------------------------------------------------- +// device_add_mconfig - add device configuration +//------------------------------------------------- + +void electron_plus2_device::device_add_mconfig(machine_config &config) +{ + /* rom sockets */ + GENERIC_SOCKET(config, m_rom[0], generic_plain_slot, "electron_rom", "bin,rom"); // ROM SLOT 13 + m_rom[0]->set_device_load(device_image_load_delegate(&electron_plus2_device::device_image_load_rom1_load, this)); + GENERIC_SOCKET(config, m_rom[1], generic_plain_slot, "electron_rom", "bin,rom"); // ROM SLOT 14 + m_rom[1]->set_device_load(device_image_load_delegate(&electron_plus2_device::device_image_load_rom2_load, this)); + GENERIC_SOCKET(config, m_rom[2], generic_plain_slot, "electron_rom", "bin,rom"); // ROM SLOT 15 + m_rom[2]->set_device_load(device_image_load_delegate(&electron_plus2_device::device_image_load_rom3_load, this)); + + /* cartridges */ + ELECTRON_CARTSLOT(config, m_cart[0], DERIVED_CLOCK(1, 1), electron_cart, nullptr); + m_cart[0]->irq_handler().set(DEVICE_SELF_OWNER, FUNC(electron_expansion_slot_device::irq_w)); + m_cart[0]->nmi_handler().set(DEVICE_SELF_OWNER, FUNC(electron_expansion_slot_device::nmi_w)); + ELECTRON_CARTSLOT(config, m_cart[1], DERIVED_CLOCK(1, 1), electron_cart, nullptr); + m_cart[1]->irq_handler().set(DEVICE_SELF_OWNER, FUNC(electron_expansion_slot_device::irq_w)); + m_cart[1]->nmi_handler().set(DEVICE_SELF_OWNER, FUNC(electron_expansion_slot_device::nmi_w)); + + /* via */ + VIA6522(config, m_via, DERIVED_CLOCK(1, 16)); + m_via->readpb_handler().set(m_userport, FUNC(bbc_userport_slot_device::pb_r)); + m_via->writepb_handler().set(m_userport, FUNC(bbc_userport_slot_device::pb_w)); + m_via->irq_handler().set(DEVICE_SELF_OWNER, FUNC(electron_expansion_slot_device::irq_w)); + + /* user port */ + BBC_USERPORT_SLOT(config, m_userport, bbc_userport_devices, nullptr); + m_userport->cb1_handler().set(m_via, FUNC(via6522_device::write_cb1)); + m_userport->cb2_handler().set(m_via, FUNC(via6522_device::write_cb2)); + + /* pass-through */ + ELECTRON_EXPANSION_SLOT(config, m_exp, DERIVED_CLOCK(1, 1), electron_expansion_devices, nullptr); + m_exp->irq_handler().set(DEVICE_SELF_OWNER, FUNC(electron_expansion_slot_device::irq_w)); + m_exp->nmi_handler().set(DEVICE_SELF_OWNER, FUNC(electron_expansion_slot_device::nmi_w)); +} + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// electron_plus2_device - constructor +//------------------------------------------------- + +electron_plus2_device::electron_plus2_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) + : device_t(mconfig, ELECTRON_PLUS2, tag, owner, clock) + , device_electron_expansion_interface(mconfig, *this) + , m_exp(*this, "exp") + , m_via(*this, "via6522") + , m_rom(*this, "rom%u", 1) + , m_cart(*this, "cart%u", 1) + , m_userport(*this, "userport") + , m_romsel(0) +{ +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void electron_plus2_device::device_start() +{ +} + + +//------------------------------------------------- +// expbus_r - expansion data read +//------------------------------------------------- + +uint8_t electron_plus2_device::expbus_r(offs_t offset) +{ + uint8_t data = 0xff; + + switch (offset >> 12) + { + case 0x8: + case 0x9: + case 0xa: + case 0xb: + switch (m_romsel) + { + case 4: + case 5: + data = m_cart[1]->read(offset & 0x3fff, 0, 0, m_romsel & 0x01, 1, 0); + break; + case 6: + case 7: + data = m_cart[0]->read(offset & 0x3fff, 0, 0, m_romsel & 0x01, 1, 0); + break; + case 13: + data &= m_cart[0]->read(offset & 0x3fff, 0, 0, m_romsel & 0x01, 0, 1); + data &= m_cart[1]->read(offset & 0x3fff, 0, 0, m_romsel & 0x01, 0, 1); + case 14: + case 15: + data &= m_rom[m_romsel - 13]->read_rom(offset & 0x3fff); + break; + } + break; + + case 0xf: + switch (offset >> 8) + { + case 0xfc: + data &= m_cart[0]->read(offset & 0xff, 1, 0, m_romsel & 0x01, 0, 0); + data &= m_cart[1]->read(offset & 0xff, 1, 0, m_romsel & 0x01, 0, 0); + + if (offset >= 0xfcb0 && offset < 0xfcc0) + { + data &= m_via->read(offset & 0x0f); + } + break; + + case 0xfd: + data &= m_cart[0]->read(offset & 0xff, 0, 1, m_romsel & 0x01, 0, 0); + data &= m_cart[1]->read(offset & 0xff, 0, 1, m_romsel & 0x01, 0, 0); + break; + } + } + + data &= m_exp->expbus_r(offset); + + return data; +} + + +//------------------------------------------------- +// expbus_w - expansion data write +//------------------------------------------------- + +void electron_plus2_device::expbus_w(offs_t offset, uint8_t data) +{ + switch (offset >> 12) + { + case 0x8: + case 0x9: + case 0xa: + case 0xb: + switch (m_romsel) + { + case 4: + case 5: + m_cart[1]->write(offset & 0x3fff, data, 0, 0, m_romsel & 0x01, 1, 0); + break; + case 6: + case 7: + m_cart[0]->write(offset & 0x3fff, data, 0, 0, m_romsel & 0x01, 1, 0); + break; + } + break; + + case 0xf: + switch (offset >> 8) + { + case 0xfc: + m_cart[0]->write(offset & 0xff, data, 1, 0, m_romsel & 0x01, 0, 0); + m_cart[1]->write(offset & 0xff, data, 1, 0, m_romsel & 0x01, 0, 0); + + if (offset >= 0xfcb0 && offset < 0xfcc0) + { + m_via->write(offset & 0x0f, data); + } + break; + + case 0xfd: + m_cart[0]->write(offset & 0xff, data, 0, 1, m_romsel & 0x01, 0, 0); + m_cart[1]->write(offset & 0xff, data, 0, 1, m_romsel & 0x01, 0, 0); + break; + + case 0xfe: + if (offset == 0xfe05) + { + m_romsel = data & 0x0f; + } + break; + } + } + + m_exp->expbus_w(offset, data); +} + + +//************************************************************************** +// IMPLEMENTATION +//************************************************************************** + +image_init_result electron_plus2_device::load_rom(device_image_interface &image, generic_slot_device *slot) +{ + uint32_t size = slot->common_get_size("rom"); + + // socket accepts 8K and 16K ROM only + if (size != 0x2000 && size != 0x4000) + { + image.seterror(IMAGE_ERROR_UNSPECIFIED, "Invalid size: Only 8K/16K is supported"); + return image_init_result::FAIL; + } + + slot->rom_alloc(0x4000, GENERIC_ROM8_WIDTH, ENDIANNESS_LITTLE); + slot->common_load_rom(slot->get_rom_base(), size, "rom"); + + // mirror 8K ROMs + uint8_t *crt = slot->get_rom_base(); + if (size <= 0x2000) memcpy(crt + 0x2000, crt, 0x2000); + + return image_init_result::PASS; +} |