summaryrefslogtreecommitdiffstatshomepage
path: root/src/devices/bus/electron/plus2.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/devices/bus/electron/plus2.cpp')
-rw-r--r--src/devices/bus/electron/plus2.cpp236
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;
+}