trunk/src/mess/machine/coco.c
| r241538 | r241539 | |
|---|
| 678 | 678 | */ |
| 679 | 679 | UINT8 single_bit_sound = (m_pia_1->b_output() & 0x02) ? 0x80 : 0x00; |
| 680 | 680 | |
| 681 | | /* determine the sound mux status */ |
| 682 | | soundmux_status_t status = soundmux_status(); |
| 681 | /* determine the sound mux status */
|
| 682 | soundmux_status_t status = soundmux_status();
|
| 683 | |
| 684 | /* the SC77526 DAC chip internally biases the AC-coupled sound inputs for Cassette and Cartridge at the midpoint of the 3.9v output range */
|
| 685 | bool bCassSoundEnable = (status == (SOUNDMUX_ENABLE | SOUNDMUX_SEL1));
|
| 686 | bool bCartSoundEnable = (status == (SOUNDMUX_ENABLE | SOUNDMUX_SEL2));
|
| 687 | UINT8 cassette_sound = (bCassSoundEnable ? 0x40 : 0);
|
| 688 | UINT8 cart_sound = (bCartSoundEnable ? 0x40 : 0);
|
| 689 | |
| 690 | /* determine the value to send to the DAC */
|
| 691 | m_dac_output = (m_pia_1->a_output() & 0xFC) >> 2;
|
| 692 | UINT8 dac_sound = (status == SOUNDMUX_ENABLE ? m_dac_output << 1 : 0);
|
| 693 | m_dac->write_unsigned8(single_bit_sound + dac_sound + cassette_sound + cart_sound);
|
| 694 | |
| 695 | /* determine the cassette sound status */
|
| 696 | cassette_state cas_sound = bCassSoundEnable ? CASSETTE_SPEAKER_ENABLED : CASSETTE_SPEAKER_MUTED;
|
| 697 | m_cassette->change_state(cas_sound, CASSETTE_MASK_SPEAKER);
|
| 698 | |
| 699 | /* determine the cartridge sound status */
|
| 700 | m_cococart->cart_set_line(COCOCART_LINE_SOUND_ENABLE, bCartSoundEnable ? COCOCART_LINE_VALUE_ASSERT : COCOCART_LINE_VALUE_CLEAR);
|
| 701 | }
|
| 702 | |
| 703 | |
| 683 | 704 | |
| 684 | | /* determine the value to send to the DAC */ |
| 685 | | m_dac_output = (m_pia_1->a_output() & 0xFC) >> 2; |
| 686 | | UINT8 sound_output = single_bit_sound + (status == SOUNDMUX_ENABLE ? m_dac_output << 1 : 0); |
| 687 | | m_dac->write_unsigned8(sound_output); |
| 688 | | |
| 689 | | /* determine the cassette sound status */ |
| 690 | | cassette_state cas_sound = (status == (SOUNDMUX_ENABLE | SOUNDMUX_SEL1)) |
| 691 | | ? CASSETTE_SPEAKER_ENABLED |
| 692 | | : CASSETTE_SPEAKER_MUTED; |
| 693 | | m_cassette->change_state(cas_sound, CASSETTE_MASK_SPEAKER); |
| 694 | | |
| 695 | | /* determine the cartridge sound status */ |
| 696 | | m_cococart->cart_set_line( |
| 697 | | COCOCART_LINE_SOUND_ENABLE, |
| 698 | | (status == (SOUNDMUX_ENABLE | SOUNDMUX_SEL2)) ? COCOCART_LINE_VALUE_ASSERT : COCOCART_LINE_VALUE_CLEAR); |
| 699 | | } |
| 700 | | |
| 701 | | |
| 702 | | |
| 703 | 705 | //------------------------------------------------- |
| 704 | 706 | // joystick_type - returns the type of joystick |
| 705 | 707 | // in the specified port |