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Diffstat (limited to 'src/devices/bus/bbc/1mhzbus/multiform.cpp')
-rw-r--r--src/devices/bus/bbc/1mhzbus/multiform.cpp195
1 files changed, 195 insertions, 0 deletions
diff --git a/src/devices/bus/bbc/1mhzbus/multiform.cpp b/src/devices/bus/bbc/1mhzbus/multiform.cpp
new file mode 100644
index 00000000000..c3830db5d6e
--- /dev/null
+++ b/src/devices/bus/bbc/1mhzbus/multiform.cpp
@@ -0,0 +1,195 @@
+// license:BSD-3-Clause
+// copyright-holders:Nigel Barnes
+/**********************************************************************
+
+ PEDL Multiform Z80 2nd processor
+
+ http://chrisacorns.computinghistory.org.uk/8bit_Upgrades/Technomatic_MultiformZ80.html
+
+ TODO:
+ - Find utility disc, library disc, and manual
+
+**********************************************************************/
+
+
+#include "emu.h"
+#include "multiform.h"
+#include "softlist_dev.h"
+
+
+//**************************************************************************
+// DEVICE DEFINITIONS
+//**************************************************************************
+
+DEFINE_DEVICE_TYPE(BBC_MULTIFORM, bbc_multiform_device, "bbc_multiform", "PEDL Multiform Z80")
+
+
+//-------------------------------------------------
+// ADDRESS_MAP( z80_mem )
+//-------------------------------------------------
+
+void bbc_multiform_device::z80_mem(address_map &map)
+{
+ map(0x0000, 0xffff).rw(FUNC(bbc_multiform_device::mem_r), FUNC(bbc_multiform_device::mem_w));
+}
+
+//-------------------------------------------------
+// ADDRESS_MAP( z80_io )
+//-------------------------------------------------
+
+void bbc_multiform_device::z80_io(address_map &map)
+{
+ map.global_mask(0xff);
+ map(0x00, 0x00).r(m_host_latch[0], FUNC(generic_latch_8_device::read)).w(m_parasite_latch[0], FUNC(generic_latch_8_device::write));
+ map(0x01, 0x01).r(m_host_latch[1], FUNC(generic_latch_8_device::read)).w(m_parasite_latch[1], FUNC(generic_latch_8_device::write));
+ map(0x80, 0x80).w(FUNC(bbc_multiform_device::rom_disable_w));
+}
+
+//-------------------------------------------------
+// ROM( multiform )
+//-------------------------------------------------
+
+ROM_START(multiform)
+ ROM_REGION(0x2000, "osm", 0)
+ ROM_LOAD("osmv200.rom", 0x0000, 0x2000, CRC(67ce1713) SHA1(314ee6211a7af6cab659640fbdd11f1078460f08))
+
+ ROM_REGION(0x4000, "exp_rom", 0)
+ ROM_LOAD("osmz80v137.rom", 0x0000, 0x4000, CRC(79a8de8f) SHA1(0bc06ce54ab9a2242294bbbe9ce8f07e464bb674))
+ROM_END
+
+//-------------------------------------------------
+// device_add_mconfig - add device configuration
+//-------------------------------------------------
+
+void bbc_multiform_device::device_add_mconfig(machine_config &config)
+{
+ Z80(config, m_z80, 8_MHz_XTAL / 2);
+ m_z80->set_addrmap(AS_PROGRAM, &bbc_multiform_device::z80_mem);
+ m_z80->set_addrmap(AS_IO, &bbc_multiform_device::z80_io);
+ m_z80->set_irq_acknowledge_callback(FUNC(bbc_multiform_device::irq_callback));
+
+ /* 74ls374 */
+ GENERIC_LATCH_8(config, m_host_latch[0]);
+ GENERIC_LATCH_8(config, m_host_latch[1]);
+ GENERIC_LATCH_8(config, m_parasite_latch[0]);
+ GENERIC_LATCH_8(config, m_parasite_latch[1]);
+
+ /* software lists */
+ SOFTWARE_LIST(config, "flop_ls_z80").set_original("bbc_flop_z80");
+}
+
+//-------------------------------------------------
+// rom_region - device-specific ROM region
+//-------------------------------------------------
+
+const tiny_rom_entry *bbc_multiform_device::device_rom_region() const
+{
+ return ROM_NAME( multiform );
+}
+
+//**************************************************************************
+// LIVE DEVICE
+//**************************************************************************
+
+//-------------------------------------------------
+// bbc_multiform_device - constructor
+//-------------------------------------------------
+
+bbc_multiform_device::bbc_multiform_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
+ : device_t(mconfig, BBC_MULTIFORM, tag, owner, clock)
+ , device_bbc_1mhzbus_interface(mconfig, *this)
+ , m_z80(*this, "z80")
+ , m_host_latch(*this, "host_latch%u", 0U)
+ , m_parasite_latch(*this, "parasite_latch%u", 0U)
+ , m_osm(*this, "osm")
+ , m_rom_enabled(true)
+{
+}
+
+//-------------------------------------------------
+// device_start - device-specific startup
+//-------------------------------------------------
+
+void bbc_multiform_device::device_start()
+{
+ m_ram = std::make_unique<uint8_t[]>(0x10000);
+
+ /* register for save states */
+ save_pointer(NAME(m_ram), 0x10000);
+ save_item(NAME(m_rom_enabled));
+}
+
+//-------------------------------------------------
+// device_reset - device-specific reset
+//-------------------------------------------------
+
+void bbc_multiform_device::device_reset()
+{
+ m_rom_enabled = true;
+}
+
+//**************************************************************************
+// IMPLEMENTATION
+//**************************************************************************
+
+uint8_t bbc_multiform_device::fred_r(offs_t offset)
+{
+ uint8_t data = 0xff;
+
+ switch (offset)
+ {
+ case 0x00:
+ data = m_parasite_latch[0]->read();
+ break;
+ case 0x01:
+ data = m_parasite_latch[1]->read();
+ break;
+ }
+
+ return data;
+}
+
+void bbc_multiform_device::fred_w(offs_t offset, uint8_t data)
+{
+ switch (offset)
+ {
+ case 0x00:
+ m_host_latch[0]->write(data);
+ break;
+ case 0x01:
+ m_host_latch[1]->write(data);
+ break;
+ }
+}
+
+READ8_MEMBER(bbc_multiform_device::mem_r)
+{
+ uint8_t data;
+
+ if (m_rom_enabled && offset < 0x2000)
+ data = m_osm->base()[offset & 0x1fff];
+ else
+ data = m_ram[offset];
+
+ return data;
+}
+
+WRITE8_MEMBER(bbc_multiform_device::mem_w)
+{
+ m_ram[offset] = data;
+}
+
+WRITE8_MEMBER(bbc_multiform_device::rom_disable_w)
+{
+ if (!machine().side_effects_disabled())
+ m_rom_enabled = false;
+}
+
+//-------------------------------------------------
+// irq vector callback
+//-------------------------------------------------
+
+IRQ_CALLBACK_MEMBER(bbc_multiform_device::irq_callback)
+{
+ return 0xfe;
+}