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Diffstat (limited to 'src/mame/drivers/spec128.cpp')
-rw-r--r--src/mame/drivers/spec128.cpp20
1 files changed, 17 insertions, 3 deletions
diff --git a/src/mame/drivers/spec128.cpp b/src/mame/drivers/spec128.cpp
index 5e15f436fb1..b005bb8fae9 100644
--- a/src/mame/drivers/spec128.cpp
+++ b/src/mame/drivers/spec128.cpp
@@ -165,9 +165,18 @@ resulting mess can be seen in the F4 viewer display.
/****************************************************************************************************/
/* Spectrum 128 specific functions */
+READ8_MEMBER(spectrum_state::spectrum_128_opcode_fetch_r)
+{
+ /* this allows expansion devices to act upon opcode fetches from MEM addresses */
+ if (BIT(m_port_7ffd_data, 4))
+ m_exp->opcode_fetch(offset);
+
+ return m_maincpu->space(AS_PROGRAM).read_byte(offset);
+}
+
WRITE8_MEMBER( spectrum_state::spectrum_128_bank1_w )
{
- if (m_exp->romcs())
+ if (m_exp->romcs() && BIT(m_port_7ffd_data, 4))
m_exp->mreq_w(offset, data);
}
@@ -175,7 +184,7 @@ READ8_MEMBER( spectrum_state::spectrum_128_bank1_r )
{
uint8_t data;
- if (m_exp->romcs())
+ if (m_exp->romcs() && BIT(m_port_7ffd_data, 4))
{
data = m_exp->mreq_r(offset);
}
@@ -251,6 +260,11 @@ void spectrum_state::spectrum_128_mem(address_map &map)
map(0xc000, 0xffff).bankrw("bank4");
}
+void spectrum_state::spectrum_128_fetch(address_map &map)
+{
+ map(0x0000, 0xffff).r(FUNC(spectrum_state::spectrum_128_opcode_fetch_r));
+}
+
MACHINE_RESET_MEMBER(spectrum_state,spectrum_128)
{
uint8_t *messram = m_ram->pointer();
@@ -298,7 +312,7 @@ void spectrum_state::spectrum_128(machine_config &config)
Z80(config.replace(), m_maincpu, X1_128_SINCLAIR / 5);
m_maincpu->set_addrmap(AS_PROGRAM, &spectrum_state::spectrum_128_mem);
m_maincpu->set_addrmap(AS_IO, &spectrum_state::spectrum_128_io);
- m_maincpu->set_addrmap(AS_OPCODES, &spectrum_state::spectrum_fetch);
+ m_maincpu->set_addrmap(AS_OPCODES, &spectrum_state::spectrum_128_fetch);
m_maincpu->set_vblank_int("screen", FUNC(spectrum_state::spec_interrupt));
config.m_minimum_quantum = attotime::from_hz(60);