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savant: remove mid-opcode Z80 WAIT workaround, but now MAME hardlocks

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This commit is contained in:
hap 2024-06-11 12:00:04 +02:00
parent ca9069617e
commit 1cd5dded35
1 changed files with 19 additions and 21 deletions
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40
src/mame/novag/savant.cpp
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@ -21,9 +21,6 @@ Hardware overview:
The display (both the LCD and the sensors) didn't last long, probably none exist
anymore in original working order.
TODO:
- get rid of m_wait_in hack when Z80 core accurately emulates WAIT pin
*******************************************************************************/
#include "emu.h"
@ -68,6 +65,7 @@ public:
protected:
virtual void machine_start() override;
virtual void machine_reset() override;
private:
// devices/pointers
@ -82,7 +80,7 @@ private:
required_shared_ptr<u8> m_nvram;
required_ioport_array<3> m_inputs;
bool m_wait_in = false;
bool m_z80_wait = false;
u8 m_inp_mux = 0;
u8 m_databus = 0;
u8 m_control = 0;
@ -115,13 +113,18 @@ private:
void savant_state::machine_start()
{
// register for savestates
save_item(NAME(m_wait_in));
save_item(NAME(m_z80_wait));
save_item(NAME(m_inp_mux));
save_item(NAME(m_databus));
save_item(NAME(m_control));
save_item(NAME(m_lcd_data));
}
void savant_state::machine_reset()
{
m_z80_wait = false;
}
/*******************************************************************************
@ -144,22 +147,24 @@ u8 savant_state::nvram_r(offs_t offset)
void savant_state::stall_w(offs_t offset, u8 data)
{
// any access to port C0 puts the Z80 into WAIT, sets BUSRQ, and sets MCU EXT INT
m_databus = offset >> 8;
m_psu->ext_int_w(1);
m_maincpu->set_input_line(Z80_INPUT_LINE_WAIT, ASSERT_LINE);
m_maincpu->set_input_line(Z80_INPUT_LINE_BUSRQ, ASSERT_LINE);
if (!m_z80_wait)
{
m_databus = offset >> 8;
m_psu->ext_int_w(1);
m_maincpu->set_input_line(Z80_INPUT_LINE_WAIT, ASSERT_LINE);
m_maincpu->set_input_line(Z80_INPUT_LINE_BUSRQ, ASSERT_LINE);
m_maincpu->defer_access();
}
m_z80_wait = !m_z80_wait;
}
u8 savant_state::stall_r(offs_t offset)
{
if (!machine().side_effects_disabled())
{
m_wait_in = true;
stall_w(offset);
}
// return value is databus (see control_w)
return 0;
return m_databus;
}
u8 savant_state::mcustatus_r()
@ -206,13 +211,6 @@ void savant_state::control_w(u8 data)
{
m_psu->ext_int_w(0);
m_maincpu->set_input_line(Z80_INPUT_LINE_WAIT, CLEAR_LINE);
// hack to set Z80 A after IN A,($C0)
if (m_wait_in)
{
m_maincpu->set_state_int(Z80_A, m_databus);
m_wait_in = false;
}
}
// d1: clear Z80 BUSRQ