diff options
Diffstat (limited to 'src/mame/audio/qix.cpp')
-rw-r--r-- | src/mame/audio/qix.cpp | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/src/mame/audio/qix.cpp b/src/mame/audio/qix.cpp new file mode 100644 index 00000000000..8d9f6ecb7ca --- /dev/null +++ b/src/mame/audio/qix.cpp @@ -0,0 +1,221 @@ +// license:??? +// copyright-holders:John Butler, Ed Mueller, Aaron Giles +/************************************************************************* + + audio/qix.c + +*************************************************************************/ + +#include "emu.h" +#include "cpu/m6800/m6800.h" +#include "cpu/m6809/m6809.h" +#include "includes/qix.h" +#include "sound/sn76496.h" +#include "sound/discrete.h" + +/* Discrete Sound Input Nodes */ +#define QIX_DAC_DATA NODE_01 +#define QIX_VOL_DATA NODE_02 +#define QIX_VOL_DATA_L NODE_03 +#define QIX_VOL_DATA_R NODE_04 + + + + + + +/*************************************************************************** +Audio handlers +***************************************************************************/ + +WRITE8_MEMBER(qix_state::qix_dac_w) +{ + m_discrete->write(space, QIX_DAC_DATA, data); +} + +WRITE8_MEMBER(qix_state::qix_vol_w) +{ + m_discrete->write(space, QIX_VOL_DATA, data); +} + + +/************************************************************************/ +/* qix Sound System Analog emulation */ +/************************************************************************/ +/* + * This hardware is capable of independent L/R volume control, + * but only sdungeon uses it for a stereo effect. + * Other games just use it for fixed L/R volume control. + * + * This is such a basic sound system that there is only one effect. + * So I won't bother keeping proper voltages levels, and will just + * start with the final gain. + */ + +static const discrete_comp_adder_table qix_attn_table = +{ + DISC_COMP_P_RESISTOR, 0, 4, + {RES_K(22)+250, RES_K(10)+250, RES_K(5.6)+250, RES_K(3.3)+250} +}; + +static DISCRETE_SOUND_START(qix) + /* NODE */ + DISCRETE_INPUTX_DATA(QIX_DAC_DATA, 128, -128*128, 128) + DISCRETE_INPUT_DATA (QIX_VOL_DATA) + + /* Separate the two 4-bit channels. */ + DISCRETE_TRANSFORM3(QIX_VOL_DATA_L, QIX_VOL_DATA, 16, 0x0f, "01/2&") + DISCRETE_TRANSFORM2(QIX_VOL_DATA_R, QIX_VOL_DATA, 0x0f, "01&") + + /* Work out the parallel resistance of the selected resistors. */ + DISCRETE_COMP_ADDER(NODE_10, QIX_VOL_DATA_L, &qix_attn_table) + DISCRETE_COMP_ADDER(NODE_20, QIX_VOL_DATA_R, &qix_attn_table) + + /* Then use it for the resistor divider network. */ + DISCRETE_TRANSFORM3(NODE_11, NODE_10, RES_K(10), QIX_DAC_DATA, "001+/2*") + DISCRETE_TRANSFORM3(NODE_21, NODE_20, RES_K(10), QIX_DAC_DATA, "001+/2*") + + /* If no resistors are selected (0), then the volume is full. */ + DISCRETE_SWITCH(NODE_12, 1, QIX_VOL_DATA_L, QIX_DAC_DATA, NODE_11) + DISCRETE_SWITCH(NODE_22, 1, QIX_VOL_DATA_R, QIX_DAC_DATA, NODE_21) + + /* Filter the DC using the lowest case filter. */ + DISCRETE_CRFILTER(NODE_13, NODE_12, RES_K(1.5), CAP_U(1)) + DISCRETE_CRFILTER(NODE_23, NODE_22, RES_K(1.5), CAP_U(1)) + + DISCRETE_OUTPUT(NODE_13, 1) + DISCRETE_OUTPUT(NODE_23, 1) +DISCRETE_SOUND_END + + + +/************************************* + * + * PIA handlers + * + *************************************/ + +WRITE8_MEMBER(qix_state::sndpia_2_warning_w) +{ + popmessage("PIA 5 write!!"); +} + + +TIMER_CALLBACK_MEMBER(qix_state::deferred_sndpia1_porta_w) +{ + m_sndpia1->porta_w(param); +} + + +WRITE8_MEMBER(qix_state::sync_sndpia1_porta_w) +{ + /* we need to synchronize this so the sound CPU doesn't drop anything important */ + machine().scheduler().synchronize(timer_expired_delegate(FUNC(qix_state::deferred_sndpia1_porta_w), this), data); +} + + +WRITE8_MEMBER(qix_state::slither_coinctl_w) +{ + coin_lockout_w(machine(), 0, (~data >> 6) & 1); + coin_counter_w(machine(), 0, (data >> 5) & 1); +} + + + +/************************************* + * + * IRQ generation + * + *************************************/ + +WRITE_LINE_MEMBER(qix_state::qix_pia_dint) +{ + int combined_state = m_sndpia0->irq_a_state() | m_sndpia0->irq_b_state(); + + /* DINT is connected to the data CPU's IRQ line */ + m_maincpu->set_input_line(M6809_IRQ_LINE, combined_state ? ASSERT_LINE : CLEAR_LINE); +} + + +WRITE_LINE_MEMBER(qix_state::qix_pia_sint) +{ + int combined_state = m_sndpia1->irq_a_state() | m_sndpia1->irq_b_state(); + + /* SINT is connected to the sound CPU's IRQ line */ + m_audiocpu->set_input_line(M6800_IRQ_LINE, combined_state ? ASSERT_LINE : CLEAR_LINE); +} + + + +/************************************* + * + * Audio CPU memory handlers + * + *************************************/ + +static ADDRESS_MAP_START( audio_map, AS_PROGRAM, 8, driver_device ) + AM_RANGE(0x0000, 0x007f) AM_RAM + AM_RANGE(0x2000, 0x2003) AM_MIRROR(0x5ffc) AM_DEVREADWRITE("sndpia2", pia6821_device, read, write) + AM_RANGE(0x4000, 0x4003) AM_MIRROR(0x3ffc) AM_DEVREADWRITE("sndpia1", pia6821_device, read, write) + AM_RANGE(0xd000, 0xffff) AM_ROM +ADDRESS_MAP_END + + + + +/************************************* + * + * Machine drivers + * + *************************************/ + +MACHINE_CONFIG_FRAGMENT( qix_audio ) + MCFG_CPU_ADD("audiocpu", M6802, SOUND_CLOCK_OSC/2) /* 0.92 MHz */ + MCFG_CPU_PROGRAM_MAP(audio_map) + + MCFG_DEVICE_ADD("sndpia0", PIA6821, 0) + MCFG_PIA_WRITEPA_HANDLER(WRITE8(qix_state, sync_sndpia1_porta_w)) + MCFG_PIA_WRITEPB_HANDLER(WRITE8(qix_state, qix_vol_w)) + MCFG_PIA_CA2_HANDLER(DEVWRITELINE("sndpia1", pia6821_device, ca1_w)) + MCFG_PIA_CB2_HANDLER(WRITELINE(qix_state, qix_flip_screen_w)) + MCFG_PIA_IRQA_HANDLER(WRITELINE(qix_state, qix_pia_dint)) + MCFG_PIA_IRQB_HANDLER(WRITELINE(qix_state, qix_pia_dint)) + + MCFG_DEVICE_ADD("sndpia1", PIA6821, 0) + MCFG_PIA_WRITEPA_HANDLER(DEVWRITE8("sndpia0", pia6821_device, porta_w)) + MCFG_PIA_WRITEPB_HANDLER(WRITE8(qix_state,qix_dac_w)) + MCFG_PIA_CA2_HANDLER(DEVWRITELINE("sndpia0", pia6821_device, ca1_w)) + MCFG_PIA_IRQA_HANDLER(WRITELINE(qix_state, qix_pia_sint)) + MCFG_PIA_IRQB_HANDLER(WRITELINE(qix_state, qix_pia_sint)) + + MCFG_DEVICE_ADD("sndpia2", PIA6821, 0) + MCFG_PIA_WRITEPA_HANDLER(WRITE8(qix_state, sndpia_2_warning_w)) + MCFG_PIA_WRITEPB_HANDLER(WRITE8(qix_state, sndpia_2_warning_w)) + MCFG_PIA_CA2_HANDLER(WRITE8(qix_state, sndpia_2_warning_w)) + MCFG_PIA_CB2_HANDLER(WRITE8(qix_state, sndpia_2_warning_w)) + + MCFG_SPEAKER_STANDARD_STEREO("lspeaker", "rspeaker") + + MCFG_SOUND_ADD("discrete", DISCRETE, 0) + MCFG_DISCRETE_INTF(qix) + MCFG_SOUND_ROUTE(0, "lspeaker", 1.0) + MCFG_SOUND_ROUTE(1, "rspeaker", 1.0) +MACHINE_CONFIG_END + + +MACHINE_CONFIG_FRAGMENT( slither_audio ) + MCFG_DEVICE_ADD("sndpia0", PIA6821, 0) + MCFG_PIA_READPA_HANDLER(IOPORT("P2")) + MCFG_PIA_WRITEPB_HANDLER(WRITE8(qix_state, slither_coinctl_w)) + MCFG_PIA_CB2_HANDLER(WRITELINE(qix_state, qix_flip_screen_w)) + MCFG_PIA_IRQA_HANDLER(WRITELINE(qix_state, qix_pia_dint)) + MCFG_PIA_IRQB_HANDLER(WRITELINE(qix_state, qix_pia_dint)) + + MCFG_SPEAKER_STANDARD_MONO("mono") + + MCFG_SOUND_ADD("sn1", SN76489, SLITHER_CLOCK_OSC/4/4) + MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.50) + + MCFG_SOUND_ADD("sn2", SN76489, SLITHER_CLOCK_OSC/4/4) + MCFG_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.50) +MACHINE_CONFIG_END |