diff options
Diffstat (limited to 'src/mess/machine/a2softcard.c')
-rw-r--r-- | src/mess/machine/a2softcard.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/src/mess/machine/a2softcard.c b/src/mess/machine/a2softcard.c new file mode 100644 index 00000000000..adc2836941e --- /dev/null +++ b/src/mess/machine/a2softcard.c @@ -0,0 +1,192 @@ +/********************************************************************* + + a2softcard.c + + Implementation of the Microsoft SoftCard Z-80 card + +*********************************************************************/ + +#include "a2softcard.h" +#include "includes/apple2.h" +#include "cpu/z80/z80.h" + +/*************************************************************************** + PARAMETERS +***************************************************************************/ + +//************************************************************************** +// GLOBAL VARIABLES +//************************************************************************** + +const device_type A2BUS_SOFTCARD = &device_creator<a2bus_softcard_device>; + +#define Z80_TAG "z80" + +static ADDRESS_MAP_START( z80_mem, AS_PROGRAM, 8, a2bus_softcard_device ) + AM_RANGE(0x0000, 0xffff) AM_READWRITE(dma_r, dma_w) +ADDRESS_MAP_END + +MACHINE_CONFIG_FRAGMENT( a2softcard ) + MCFG_CPU_ADD(Z80_TAG, Z80, 1021800*2) // Z80 runs on double the Apple II's clock + MCFG_CPU_PROGRAM_MAP(z80_mem) +MACHINE_CONFIG_END + +/*************************************************************************** + FUNCTION PROTOTYPES +***************************************************************************/ + +//------------------------------------------------- +// machine_config_additions - device-specific +// machine configurations +//------------------------------------------------- + +machine_config_constructor a2bus_softcard_device::device_mconfig_additions() const +{ + return MACHINE_CONFIG_NAME( a2softcard ); +} + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +a2bus_softcard_device::a2bus_softcard_device(const machine_config &mconfig, device_type type, const char *name, const char *tag, device_t *owner, UINT32 clock) : + device_t(mconfig, type, name, tag, owner, clock), + device_a2bus_card_interface(mconfig, *this), + m_z80(*this, Z80_TAG), + m_6502space(NULL) +{ + m_shortname = "a2softcard"; +} + +a2bus_softcard_device::a2bus_softcard_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : + device_t(mconfig, A2BUS_SOFTCARD, "Microsoft SoftCard", tag, owner, clock), + device_a2bus_card_interface(mconfig, *this), + m_z80(*this, Z80_TAG), + m_6502space(NULL) +{ + m_shortname = "a2softcard"; +} + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void a2bus_softcard_device::device_start() +{ + // set_a2bus_device makes m_slot valid + set_a2bus_device(); + + save_item(NAME(m_bEnabled)); + save_item(NAME(m_FirstZ80Boot)); +} + +void a2bus_softcard_device::device_reset() +{ + m_bEnabled = false; + m_6502space = NULL; + m_FirstZ80Boot = true; + device_set_input_line(m_z80, INPUT_LINE_HALT, ASSERT_LINE); +} + +void a2bus_softcard_device::write_cnxx(address_space &space, UINT8 offset, UINT8 data) +{ + apple2_state *state = machine().driver_data<apple2_state>(); + + if (!m_bEnabled) + { + // steal the 6502's address space + m_6502space = &space; + + device_set_input_line(m_z80, INPUT_LINE_HALT, CLEAR_LINE); + device_set_input_line(state->m_maincpu, INPUT_LINE_HALT, ASSERT_LINE); + + if (m_FirstZ80Boot) + { + m_FirstZ80Boot = false; + m_z80->reset(); + } + + m_bEnabled = true; + } + else + { + device_set_input_line(m_z80, INPUT_LINE_HALT, ASSERT_LINE); + device_set_input_line(state->m_maincpu, INPUT_LINE_HALT, CLEAR_LINE); + m_bEnabled = false; + } +} + +READ8_MEMBER( a2bus_softcard_device::dma_r ) +{ + if (m_6502space) + { + if (offset <= 0xafff) + { + return m_6502space->read_byte(offset+0x1000); + } + else if (offset <= 0xbfff) // LC bank 2 d000-dfff + { + return m_6502space->read_byte((offset&0xfff) + 0xd000); + } + else if (offset <= 0xcfff) // LC e000-efff + { + return m_6502space->read_byte((offset&0xfff) + 0xe000); + } + else if (offset <= 0xdfff) // LC f000-ffff (or ROM?) + { + return m_6502space->read_byte((offset&0xfff) + 0xf000); + } + else if (offset <= 0xefff) // I/O space c000-cfff + { + return m_6502space->read_byte((offset&0xfff) + 0xc000); + } + else // zero page + { + return m_6502space->read_byte(offset&0xfff); + } + } + + return 0xff; +} + + +//------------------------------------------------- +// dma_w - +//------------------------------------------------- + +WRITE8_MEMBER( a2bus_softcard_device::dma_w ) +{ + if (m_6502space) + { + if (offset <= 0xafff) + { + m_6502space->write_byte(offset+0x1000, data); + } + else if (offset <= 0xbfff) // LC bank 2 d000-dfff + { + m_6502space->write_byte((offset&0xfff) + 0xd000, data); + } + else if (offset <= 0xcfff) // LC e000-efff + { + m_6502space->write_byte((offset&0xfff) + 0xe000, data); + } + else if (offset <= 0xdfff) // LC f000-ffff (or ROM?) + { + m_6502space->write_byte((offset&0xfff) + 0xf000, data); + } + else if (offset <= 0xefff) // I/O space c000-cfff + { + m_6502space->write_byte((offset&0xfff) + 0xc000, data); + } + else // zero page + { + m_6502space->write_byte(offset&0xfff, data); + } + } +} + +bool a2bus_softcard_device::take_c800() +{ + return false; +} + |