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multipcm: Found the real 12-bit format flag. [R. Belmont]

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mu5: Adjusted PCM clock closer to correct. [R. Belmont]
This commit is contained in:
arbee 2020-11-08 17:49:19 -05:00
parent e88b622619
commit feaaccb7e7
2 changed files with 6 additions and 3 deletions
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7
src/devices/sound/multipcm.cpp
View File

@ -21,7 +21,9 @@
* bytes per instrument sample. This is very similar to the YMF278B 'OPL4'.
* This sample format might be derived from the one used by the older YM7138 'GEW6' chip.
*
* The first 3 bytes are the offset into the file (big endian). (0, 1, 2)
* The first 3 bytes are the offset into the file (big endian). (0, 1, 2).
Bit 23 is the sample format flag: 0 for 8-bit linear, 1 for 12-bit linear.
Bits 21 and 22 are used by the MU5 on some samples for as-yet unknown purposes.
* The next 2 are the loop start point, in samples (big endian) (3, 4)
* The next 2 are the 2's complement negation of of the total number of samples (big endian) (5, 6)
* The next byte is LFO freq + depth (copied to reg 6 ?) (7, 8)
@ -80,6 +82,7 @@ void multipcm_device::init_sample(sample_t *sample, uint32_t index)
uint32_t address = index * 12;
sample->m_start = (read_byte(address) << 16) | (read_byte(address + 1) << 8) | read_byte(address + 2);
sample->m_format = (sample->m_start>>20) & 0xfe;
sample->m_start &= 0x3fffff;
sample->m_loop = (read_byte(address + 3) << 8) | read_byte(address + 4);
sample->m_end = 0xffff - ((read_byte(address + 5) << 8) | read_byte(address + 6));
@ -328,7 +331,6 @@ void multipcm_device::write_slot(slot_t &slot, int32_t reg, uint8_t data)
{
case 0: // PANPOT
slot.m_pan = (data >> 4) & 0xf;
slot.m_format = (data & 0x0f); // bit 3: 0 = 8-bit linear, 1 = 12-bit linear
break;
case 1: // Sample
@ -367,6 +369,7 @@ void multipcm_device::write_slot(slot_t &slot, int32_t reg, uint8_t data)
slot.m_offset = 0;
slot.m_prev_sample = 0;
slot.m_total_level = slot.m_dest_total_level << TL_SHIFT;
slot.m_format = slot.m_sample.m_format;
envelope_generator_calc(slot);
slot.m_envelope_gen.m_state = state_t::ATTACK;

2
src/mame/drivers/ymmu5.cpp
View File

@ -225,7 +225,7 @@ void mu5_state::mu5(machine_config &config)
SPEAKER(config, "lspeaker").front_left();
SPEAKER(config, "rspeaker").front_right();
MULTIPCM(config, m_ymw258, 9400000);
MULTIPCM(config, m_ymw258, 7500000);
m_ymw258->set_addrmap(0, &mu5_state::ymw258_map);
m_ymw258->add_route(0, "lspeaker", 1.0);
m_ymw258->add_route(1, "rspeaker", 1.0);