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Diffstat (limited to 'src/mame/drivers/scorpion.cpp')
-rw-r--r--src/mame/drivers/scorpion.cpp79
1 files changed, 43 insertions, 36 deletions
diff --git a/src/mame/drivers/scorpion.cpp b/src/mame/drivers/scorpion.cpp
index 1f2b7596edb..decdd724182 100644
--- a/src/mame/drivers/scorpion.cpp
+++ b/src/mame/drivers/scorpion.cpp
@@ -23,7 +23,9 @@ public:
, m_beta(*this, BETA_DISK_TAG)
{ }
- DECLARE_DIRECT_UPDATE_MEMBER(scorpion_direct);
+ DECLARE_READ8_MEMBER(beta_neutral_r);
+ DECLARE_READ8_MEMBER(beta_enable_r);
+ DECLARE_READ8_MEMBER(beta_disable_r);
DECLARE_WRITE8_MEMBER(scorpion_0000_w);
DECLARE_WRITE8_MEMBER(scorpion_port_7ffd_w);
DECLARE_WRITE8_MEMBER(scorpion_port_1ffd_w);
@@ -37,6 +39,7 @@ protected:
required_memory_bank m_bank4;
required_device<beta_disk_device> m_beta;
private:
+ address_space *m_program;
uint8_t *m_p_ram;
void scorpion_update_memory();
@@ -107,37 +110,6 @@ WRITE8_MEMBER(scorpion_state::scorpion_0000_w)
}
}
-
-DIRECT_UPDATE_MEMBER(scorpion_state::scorpion_direct)
-{
- uint16_t pc = m_maincpu->device_t::safe_pcbase(); // works, but...
-
- m_ram_disabled_by_beta = 0;
- if (m_beta->is_active() && (pc >= 0x4000))
- {
- m_ROMSelection = BIT(m_port_7ffd_data, 4);
- m_beta->disable();
- m_ram_disabled_by_beta = 1;
- m_bank1->set_base(&m_p_ram[0x10000 + (m_ROMSelection<<14)]);
- }
- else
- if (((pc & 0xff00) == 0x3d00) && (m_ROMSelection==1))
- {
- m_ROMSelection = 3;
- m_beta->enable();
- }
-
- if(address<=0x3fff)
- {
- m_ram_disabled_by_beta = 1;
- direct.explicit_configure(0x0000, 0x3fff, 0x3fff, &m_p_ram[0x10000 + (m_ROMSelection<<14)]);
- m_bank1->set_base(&m_p_ram[0x10000 + (m_ROMSelection<<14)]);
- return ~0;
- }
-
- return address;
-}
-
TIMER_DEVICE_CALLBACK_MEMBER(scorpion_state::nmi_check_callback)
{
if ((m_io_nmi->read() & 1)==1)
@@ -167,6 +139,36 @@ WRITE8_MEMBER(scorpion_state::scorpion_port_1ffd_w)
scorpion_update_memory();
}
+READ8_MEMBER(scorpion_state::beta_neutral_r)
+{
+ return m_program->read_byte(offset);
+}
+
+READ8_MEMBER(scorpion_state::beta_enable_r)
+{
+ if(m_ROMSelection == 1) {
+ m_ROMSelection = 3;
+ if (m_beta->started()) {
+ m_beta->enable();
+ m_bank1->set_base(&m_p_ram[0x10000 + (m_ROMSelection<<14)]);
+ m_ram_disabled_by_beta = 1;
+ }
+ }
+ return m_program->read_byte(offset + 0x3d00);
+}
+
+READ8_MEMBER(scorpion_state::beta_disable_r)
+{
+ if (m_beta->started() && m_beta->is_active()) {
+ m_ROMSelection = BIT(m_port_7ffd_data, 4);
+ m_beta->disable();
+ m_bank1->set_base(&m_p_ram[0x10000 + (m_ROMSelection<<14)]);
+ m_ram_disabled_by_beta = 1;
+ } else
+ m_ram_disabled_by_beta = 0;
+ return m_program->read_byte(offset + 0x4000);
+}
+
static ADDRESS_MAP_START (scorpion_io, AS_IO, 8, scorpion_state )
ADDRESS_MAP_UNMAP_HIGH
AM_RANGE(0x001f, 0x001f) AM_DEVREADWRITE(BETA_DISK_TAG, beta_disk_device, status_r, command_w) AM_MIRROR(0xff00)
@@ -181,19 +183,23 @@ static ADDRESS_MAP_START (scorpion_io, AS_IO, 8, scorpion_state )
AM_RANGE(0x0021, 0x0021) AM_WRITE(scorpion_port_1ffd_w) AM_MIRROR(0x3fdc)
ADDRESS_MAP_END
+static ADDRESS_MAP_START (scorpion_switch, AS_DECRYPTED_OPCODES, 8, scorpion_state)
+ AM_RANGE(0x3d00, 0x3dff) AM_READ(beta_enable_r)
+ AM_RANGE(0x0000, 0x3fff) AM_READ(beta_neutral_r) // Overlap with previous because we want real addresses on the 3e00-3fff range
+ AM_RANGE(0x4000, 0xffff) AM_READ(beta_disable_r)
+ADDRESS_MAP_END
MACHINE_RESET_MEMBER(scorpion_state,scorpion)
{
uint8_t *messram = m_ram->pointer();
- address_space &space = m_maincpu->space(AS_PROGRAM);
+ m_program = &m_maincpu->space(AS_PROGRAM);
m_p_ram = memregion("maincpu")->base();
m_ram_0000 = nullptr;
- space.install_read_bank(0x0000, 0x3fff, "bank1");
- space.install_write_handler(0x0000, 0x3fff, write8_delegate(FUNC(scorpion_state::scorpion_0000_w),this));
+ m_program->install_read_bank(0x0000, 0x3fff, "bank1");
+ m_program->install_write_handler(0x0000, 0x3fff, write8_delegate(FUNC(scorpion_state::scorpion_0000_w),this));
m_beta->disable();
- space.set_direct_update_handler(direct_update_delegate(&scorpion_state::scorpion_direct, this));
memset(messram,0,256*1024);
@@ -269,6 +275,7 @@ GFXDECODE_END
static MACHINE_CONFIG_DERIVED_CLASS( scorpion, spectrum_128, scorpion_state )
MCFG_CPU_MODIFY("maincpu")
MCFG_CPU_IO_MAP(scorpion_io)
+ MCFG_CPU_DECRYPTED_OPCODES_MAP(scorpion_switch)
MCFG_MACHINE_START_OVERRIDE(scorpion_state, scorpion )
MCFG_MACHINE_RESET_OVERRIDE(scorpion_state, scorpion )