diff options
Diffstat (limited to 'src/devices/machine/64h156.c')
-rw-r--r-- | src/devices/machine/64h156.c | 652 |
1 files changed, 652 insertions, 0 deletions
diff --git a/src/devices/machine/64h156.c b/src/devices/machine/64h156.c new file mode 100644 index 00000000000..508034169dd --- /dev/null +++ b/src/devices/machine/64h156.c @@ -0,0 +1,652 @@ +// license:BSD-3-Clause +// copyright-holders:Curt Coder +/********************************************************************** + + Commodore 64H156 Gate Array emulation + +**********************************************************************/ + +/* + + TODO: + + http://personalpages.tds.net/~rcarlsen/cbm/1541/1541%20EARLY/1540-2.GIF + + - write protect + - separate read/write methods + - cycle exact VIA + - get these running and we're golden + - Bounty Bob Strikes Back (aligned halftracks) + - Quiwi (speed change within track) + - Defender of the Crown (V-MAX! v2, density checks) + - Test Drive / Cabal (HLS, sub-cycle jitter) + - Galaxian (?, needs 100% accurate VIA) + +*/ + +#include "64h156.h" + + + +//************************************************************************** +// MACROS / CONSTANTS +//************************************************************************** + +#define LOG 0 + +#define CYCLES_UNTIL_ANALOG_DESYNC 288 // 18 us + + + +//************************************************************************** +// DEVICE DEFINITIONS +//************************************************************************** + +const device_type C64H156 = &device_creator<c64h156_device>; + + + +//************************************************************************** +// LIVE DEVICE +//************************************************************************** + +//------------------------------------------------- +// c64h156_device - constructor +//------------------------------------------------- + +c64h156_device::c64h156_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : + device_t(mconfig, C64H156, "64H156", tag, owner, clock, "c64h156", __FILE__), + m_write_atn(*this), + m_write_sync(*this), + m_write_byte(*this), + m_floppy(NULL), + m_mtr(1), + m_accl(0), + m_stp(0), + m_ds(0), + m_soe(0), + m_oe(1), + m_ted(0), + m_yb(0), + m_atni(0), + m_atna(0), + m_period(attotime::from_hz(clock)) +{ + memset(&cur_live, 0x00, sizeof(cur_live)); + cur_live.tm = attotime::never; + cur_live.state = IDLE; + cur_live.next_state = -1; + cur_live.write_start_time = attotime::never; +} + + +//------------------------------------------------- +// device_start - device-specific startup +//------------------------------------------------- + +void c64h156_device::device_start() +{ + // resolve callbacks + m_write_atn.resolve_safe(); + m_write_sync.resolve_safe(); + m_write_byte.resolve_safe(); + + // allocate timer + t_gen = timer_alloc(0); + + // register for state saving + save_item(NAME(m_mtr)); + save_item(NAME(m_accl)); + save_item(NAME(m_stp)); + save_item(NAME(m_ds)); + save_item(NAME(m_soe)); + save_item(NAME(m_oe)); + save_item(NAME(m_ted)); + save_item(NAME(m_yb)); + save_item(NAME(m_atni)); + save_item(NAME(m_atna)); +} + + +//------------------------------------------------- +// device_reset - device-specific reset +//------------------------------------------------- + +void c64h156_device::device_reset() +{ + live_abort(); +} + + +//------------------------------------------------- +// device_timer - handler timer events +//------------------------------------------------- + +void c64h156_device::device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) +{ + live_sync(); + live_run(); +} + +void c64h156_device::live_start() +{ + cur_live.tm = machine().time(); + cur_live.state = RUNNING; + cur_live.next_state = -1; + + cur_live.shift_reg = 0; + cur_live.shift_reg_write = 0; + cur_live.cycle_counter = 0; + cur_live.cell_counter = 0; + cur_live.bit_counter = 0; + cur_live.ds = m_ds; + cur_live.oe = m_oe; + cur_live.soe = m_soe; + cur_live.accl = m_accl; + cur_live.zero_counter = 0; + cur_live.cycles_until_random_flux = (rand() % 31) + 289; + + checkpoint_live = cur_live; + + live_run(); +} + +void c64h156_device::checkpoint() +{ + get_next_edge(machine().time()); + checkpoint_live = cur_live; +} + +void c64h156_device::rollback() +{ + cur_live = checkpoint_live; + get_next_edge(cur_live.tm); +} + +void c64h156_device::start_writing(const attotime &tm) +{ + cur_live.write_start_time = tm; + cur_live.write_position = 0; +} + +void c64h156_device::stop_writing(const attotime &tm) +{ + commit(tm); + cur_live.write_start_time = attotime::never; +} + +bool c64h156_device::write_next_bit(bool bit, const attotime &limit) +{ + if(cur_live.write_start_time.is_never()) { + cur_live.write_start_time = cur_live.tm; + cur_live.write_position = 0; + } + + attotime etime = cur_live.tm + m_period; + if(etime > limit) + return true; + + if(bit && cur_live.write_position < ARRAY_LENGTH(cur_live.write_buffer)) + cur_live.write_buffer[cur_live.write_position++] = cur_live.tm - m_period; + + if (LOG) logerror("%s write bit %u (%u)\n", cur_live.tm.as_string(), cur_live.bit_counter, bit); + + return false; +} + +void c64h156_device::commit(const attotime &tm) +{ + if(cur_live.write_start_time.is_never() || tm == cur_live.write_start_time || !cur_live.write_position) + return; + + if (LOG) logerror("%s committing %u transitions since %s\n", tm.as_string(), cur_live.write_position, cur_live.write_start_time.as_string()); + + m_floppy->write_flux(cur_live.write_start_time, tm, cur_live.write_position, cur_live.write_buffer); + + cur_live.write_start_time = tm; + cur_live.write_position = 0; +} + +void c64h156_device::live_delay(int state) +{ + cur_live.next_state = state; + if(cur_live.tm != machine().time()) + t_gen->adjust(cur_live.tm - machine().time()); + else + live_sync(); +} + +void c64h156_device::live_sync() +{ + if(!cur_live.tm.is_never()) { + if(cur_live.tm > machine().time()) { + rollback(); + live_run(machine().time()); + commit(cur_live.tm); + } else { + commit(cur_live.tm); + if(cur_live.next_state != -1) { + cur_live.state = cur_live.next_state; + cur_live.next_state = -1; + } + if(cur_live.state == IDLE) { + stop_writing(cur_live.tm); + cur_live.tm = attotime::never; + } + } + cur_live.next_state = -1; + checkpoint(); + } +} + +void c64h156_device::live_abort() +{ + if(!cur_live.tm.is_never() && cur_live.tm > machine().time()) { + rollback(); + live_run(machine().time()); + } + + stop_writing(cur_live.tm); + + cur_live.tm = attotime::never; + cur_live.state = IDLE; + cur_live.next_state = -1; + cur_live.write_position = 0; + cur_live.write_start_time = attotime::never; + + cur_live.sync = 1; + cur_live.byte = 1; +} + +void c64h156_device::live_run(const attotime &limit) +{ + if(cur_live.state == IDLE || cur_live.next_state != -1) + return; + + for(;;) { + switch(cur_live.state) { + case RUNNING: { + bool syncpoint = false; + + if (cur_live.tm > limit) + return; + + int bit = get_next_bit(cur_live.tm, limit); + if(bit < 0) + return; + + int cell_counter = cur_live.cell_counter; + + if (bit) { + cur_live.cycle_counter = cur_live.ds; + cur_live.cell_counter = 0; + } else { + cur_live.cycle_counter++; + } + + if (cur_live.cycle_counter == 16) { + cur_live.cycle_counter = cur_live.ds; + + cur_live.cell_counter++; + cur_live.cell_counter &= 0xf; + } + + if (!BIT(cell_counter, 1) && BIT(cur_live.cell_counter, 1)) { + // read bit + cur_live.shift_reg <<= 1; + cur_live.shift_reg |= !(BIT(cur_live.cell_counter, 3) || BIT(cur_live.cell_counter, 2)); + cur_live.shift_reg &= 0x3ff; + + if (LOG) logerror("%s read bit %u (%u) >> %03x, oe=%u soe=%u sync=%u byte=%u\n", cur_live.tm.as_string(), cur_live.bit_counter, + !(BIT(cur_live.cell_counter, 3) || BIT(cur_live.cell_counter, 2)), cur_live.shift_reg, cur_live.oe, cur_live.soe, cur_live.sync, cur_live.byte); + + syncpoint = true; + } + + if (BIT(cell_counter, 1) && !BIT(cur_live.cell_counter, 1) && !cur_live.oe) { // TODO WPS + write_next_bit(BIT(cur_live.shift_reg_write, 7), limit); + } + + int sync = !((cur_live.shift_reg == 0x3ff) && cur_live.oe); + + if (!sync) { + cur_live.bit_counter = 8; + } else if (!BIT(cell_counter, 1) && BIT(cur_live.cell_counter, 1) && cur_live.sync) { + cur_live.bit_counter++; + cur_live.bit_counter &= 0xf; + } + + int byte = !(((cur_live.bit_counter & 7) == 7) && cur_live.soe && !(cur_live.cell_counter & 2)); + int load = !(((cur_live.bit_counter & 7) == 7) && ((cur_live.cell_counter & 3) == 3)); + + if (!load) { + if (cur_live.oe) { + cur_live.shift_reg_write = cur_live.shift_reg; + if (LOG) logerror("%s load write shift register from read shift register %02x\n",cur_live.tm.as_string(),cur_live.shift_reg_write); + } else { + cur_live.shift_reg_write = cur_live.yb; + if (LOG) logerror("%s load write shift register from YB %02x\n",cur_live.tm.as_string(),cur_live.shift_reg_write); + } + } else if (!BIT(cell_counter, 1) && BIT(cur_live.cell_counter, 1)) { + cur_live.shift_reg_write <<= 1; + cur_live.shift_reg_write &= 0xff; + if (LOG) logerror("%s shift write register << %02x\n", cur_live.tm.as_string(), cur_live.shift_reg_write); + } + + // update signals + if (byte != cur_live.byte) { + if (!byte || !cur_live.accl) { + if (LOG) logerror("%s BYTE %02x\n", cur_live.tm.as_string(), cur_live.shift_reg & 0xff); + cur_live.byte = byte; + syncpoint = true; + } + if (!byte) { + cur_live.accl_yb = cur_live.shift_reg & 0xff; + } + } + + if (sync != cur_live.sync) { + if (LOG) logerror("%s SYNC %u\n", cur_live.tm.as_string(),sync); + cur_live.sync = sync; + syncpoint = true; + } + + if (syncpoint) { + commit(cur_live.tm); + + cur_live.tm += m_period; + live_delay(RUNNING_SYNCPOINT); + return; + } + + cur_live.tm += m_period; + break; + } + + case RUNNING_SYNCPOINT: { + m_write_sync(cur_live.sync); + m_write_byte(cur_live.byte); + + cur_live.state = RUNNING; + checkpoint(); + break; + } + } + } +} + +void c64h156_device::get_next_edge(const attotime &when) +{ + cur_live.edge = m_floppy->get_next_transition(when); +} + +int c64h156_device::get_next_bit(attotime &tm, const attotime &limit) +{ + int bit = 0; + if (!cur_live.edge.is_never()) + { + attotime next = tm + m_period; + if (cur_live.edge < next) + { + bit = 1; + + cur_live.zero_counter = 0; + cur_live.cycles_until_random_flux = (rand() % 31) + 289; + + get_next_edge(next); + } + } + + if (cur_live.zero_counter >= cur_live.cycles_until_random_flux) { + cur_live.zero_counter = 0; + cur_live.cycles_until_random_flux = (rand() % 367) + 33; + + bit = 1; + } + + return bit && cur_live.oe; +} + + +//------------------------------------------------- +// yb_r - +//------------------------------------------------- + +READ8_MEMBER( c64h156_device::yb_r ) +{ + if (checkpoint_live.accl) { + return checkpoint_live.accl_yb; + } else { + return checkpoint_live.shift_reg; + } +} + + +//------------------------------------------------- +// yb_w - +//------------------------------------------------- + +WRITE8_MEMBER( c64h156_device::yb_w ) +{ + if (m_yb != data) + { + live_sync(); + m_yb = cur_live.yb = data; + checkpoint(); + if (LOG) logerror("%s YB %02x\n", machine().time().as_string(), data); + live_run(); + } + +} + + +//------------------------------------------------- +// test_w - test write +//------------------------------------------------- + +WRITE_LINE_MEMBER( c64h156_device::test_w ) +{ +} + + +//------------------------------------------------- +// accl_w - +//------------------------------------------------- + +WRITE_LINE_MEMBER( c64h156_device::accl_w ) +{ + if (m_accl != state) + { + live_sync(); + m_accl = cur_live.accl = state; + checkpoint(); + if (LOG) logerror("%s ACCL %u\n", machine().time().as_string(), state); + live_run(); + } +} + + +//------------------------------------------------- +// ted_w - +//------------------------------------------------- + +WRITE_LINE_MEMBER( c64h156_device::ted_w ) +{ + if (m_ted != state) + { + live_sync(); + if (m_ted && !state && cur_live.accl && !cur_live.byte) { + cur_live.byte = 1; + m_write_byte(cur_live.byte); + } + m_ted = state; + checkpoint(); + if (LOG) logerror("%s TED %u\n", machine().time().as_string(), state); + live_run(); + } +} + + +//------------------------------------------------- +// mtr_w - motor write +//------------------------------------------------- + +WRITE_LINE_MEMBER( c64h156_device::mtr_w ) +{ + if (m_mtr != state) + { + live_sync(); + m_mtr = state; + if (LOG) logerror("%s MTR %u\n", machine().time().as_string(), state); + m_floppy->mon_w(!state); + checkpoint(); + + if (m_mtr) { + if(cur_live.state == IDLE) { + live_start(); + } + } else { + live_abort(); + } + + live_run(); + } +} + + +//------------------------------------------------- +// oe_w - output enable write +//------------------------------------------------- + +WRITE_LINE_MEMBER( c64h156_device::oe_w ) +{ + if (m_oe != state) + { + live_sync(); + m_oe = cur_live.oe = state; + if (m_oe) { + stop_writing(machine().time()); + } else { + start_writing(machine().time()); + } + checkpoint(); + if (LOG) logerror("%s OE %u\n", machine().time().as_string(), state); + live_run(); + } +} + + +//------------------------------------------------- +// soe_w - SO enable write +//------------------------------------------------- + +WRITE_LINE_MEMBER( c64h156_device::soe_w ) +{ + if (m_soe != state) + { + live_sync(); + m_soe = cur_live.soe = state; + checkpoint(); + if (LOG) logerror("%s SOE %u\n", machine().time().as_string(), state); + live_run(); + } +} + + +//------------------------------------------------- +// atni_w - serial attention input write +//------------------------------------------------- + +WRITE_LINE_MEMBER( c64h156_device::atni_w ) +{ + if (LOG) logerror("ATNI %u\n", state); + + m_atni = state; + + m_write_atn(m_atni ^ m_atna); +} + + +//------------------------------------------------- +// atna_w - serial attention acknowledge write +//------------------------------------------------- + +WRITE_LINE_MEMBER( c64h156_device::atna_w ) +{ + if (LOG) logerror("ATNA %u\n", state); + + m_atna = state; + + m_write_atn(m_atni ^ m_atna); +} + + +//------------------------------------------------- +// set_floppy - +//------------------------------------------------- + +void c64h156_device::set_floppy(floppy_image_device *floppy) +{ + m_floppy = floppy; +} + + +//------------------------------------------------- +// stp_w - +//------------------------------------------------- + +void c64h156_device::stp_w(int stp) +{ + if (m_stp != stp) + { + live_sync(); + + if (m_mtr) + { + int tracks = 0; + + switch (m_stp) + { + case 0: if (stp == 1) tracks++; else if (stp == 3) tracks--; break; + case 1: if (stp == 2) tracks++; else if (stp == 0) tracks--; break; + case 2: if (stp == 3) tracks++; else if (stp == 1) tracks--; break; + case 3: if (stp == 0) tracks++; else if (stp == 2) tracks--; break; + } + + if (tracks == -1) + { + m_floppy->dir_w(1); + m_floppy->stp_w(1); + m_floppy->stp_w(0); + } + else if (tracks == 1) + { + m_floppy->dir_w(0); + m_floppy->stp_w(1); + m_floppy->stp_w(0); + } + + m_stp = stp; + } + + checkpoint(); + live_run(); + } +} + + +//------------------------------------------------- +// ds_w - density select +//------------------------------------------------- + +void c64h156_device::ds_w(int ds) +{ + if (m_ds != ds) + { + live_sync(); + m_ds = cur_live.ds = ds; + checkpoint(); + if (LOG) logerror("%s DS %u\n", machine().time().as_string(), ds); + live_run(); + } +} |