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apple2gs: fix inconsistent clocks #14495

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Merged
merged 1 commit into from
Nov 9, 2025
Merged

apple2gs: fix inconsistent clocks #14495

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19 changes: 10 additions & 9 deletions src/mame/apple/apple2gs.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -93,7 +93,8 @@ namespace {
#define A2GS_MASTER_CLOCK (XTAL(28'636'363))
#define A2GS_14M (A2GS_MASTER_CLOCK/2)
#define A2GS_7M (A2GS_MASTER_CLOCK/4)
#define A2GS_1M (A2GS_MASTER_CLOCK/28)
#define A2GS_2_8M (A2GS_MASTER_CLOCK/10)
#define A2GS_1M (XTAL(1021800))

#define A2GS_UPPERBANK_TAG "inhbank"
#define A2GS_AUXUPPER_TAG "inhaux"
Expand Down Expand Up @@ -519,7 +520,7 @@ class apple2gs_state : public driver_device
}
else
{
m_maincpu->set_unscaled_clock(1021800);
m_maincpu->set_unscaled_clock(A2GS_1M);
}
}

Expand All @@ -539,11 +540,11 @@ class apple2gs_state : public driver_device

if (isfast)
{
m_maincpu->set_unscaled_clock(A2GS_14M/5);
m_maincpu->set_unscaled_clock(A2GS_2_8M);
}
else
{
m_maincpu->set_unscaled_clock(1021800);
m_maincpu->set_unscaled_clock(A2GS_1M);
}
}

Expand Down Expand Up @@ -847,7 +848,7 @@ void apple2gs_state::machine_reset()
m_slow_counter = 0;

// always assert full speed on reset
m_maincpu->set_unscaled_clock(A2GS_14M/5);
m_maincpu->set_unscaled_clock(A2GS_2_8M);
m_last_speed = true;

m_sndglu_ctrl = 0;
Expand Down Expand Up @@ -971,7 +972,7 @@ void apple2gs_state::update_speed()
}
else
{
m_maincpu->set_unscaled_clock(isfast ? A2GS_14M / 5 : A2GS_1M);
m_maincpu->set_unscaled_clock(isfast ? A2GS_2_8M : A2GS_1M);
}
m_last_speed = isfast;
}
Expand Down Expand Up @@ -3743,7 +3744,7 @@ INPUT_PORTS_END
void apple2gs_state::apple2gs(machine_config &config)
{
/* basic machine hardware */
G65816(config, m_maincpu, A2GS_MASTER_CLOCK/10);
G65816(config, m_maincpu, A2GS_2_8M);
m_maincpu->set_addrmap(AS_PROGRAM, &apple2gs_state::apple2gs_map);
m_maincpu->set_addrmap(g65816_device::AS_VECTORS, &apple2gs_state::vectors_map);
m_maincpu->set_dasm_override(FUNC(apple2gs_state::dasm_trampoline));
Expand Down Expand Up @@ -3811,7 +3812,7 @@ void apple2gs_state::apple2gs(machine_config &config)
ADDRESS_MAP_BANK(config, A2GS_C300_TAG).set_map(&apple2gs_state::c300bank_map).set_options(ENDIANNESS_LITTLE, 8, 32, 0x100);

/* serial */
SCC85C30(config, m_scc, A2GS_14M / 2);
SCC85C30(config, m_scc, A2GS_7M);
m_scc->configure_channels(3'686'400, 3'686'400, 3'686'400, 3'686'400);
m_scc->out_int_callback().set(FUNC(apple2gs_state::scc_irq_w));
m_scc->out_txda_callback().set("printer", FUNC(rs232_port_device::write_txd));
Expand Down Expand Up @@ -3842,7 +3843,7 @@ void apple2gs_state::apple2gs(machine_config &config)
A2BUS_SLOT(config, "sl6", A2GS_7M, m_a2bus, apple2gs_cards, nullptr);
A2BUS_SLOT(config, "sl7", A2GS_7M, m_a2bus, apple2gs_cards, nullptr);

IWM(config, m_iwm, A2GS_7M, A2GS_MASTER_CLOCK/14);
IWM(config, m_iwm, A2GS_7M, A2GS_1M*2);
m_iwm->phases_cb().set(FUNC(apple2gs_state::phases_w));
m_iwm->sel35_cb().set(FUNC(apple2gs_state::sel35_w));
m_iwm->devsel_cb().set(FUNC(apple2gs_state::devsel_w));
Expand Down
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