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// 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;
}
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