// 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 "emu.h" #include "64h156.h" //************************************************************************** // MACROS / CONSTANTS //************************************************************************** #define LOG 0 #define CYCLES_UNTIL_ANALOG_DESYNC 288 // 18 us //************************************************************************** // DEVICE DEFINITIONS //************************************************************************** const device_type C64H156 = device_creator; //************************************************************************** // LIVE DEVICE //************************************************************************** //------------------------------------------------- // c64h156_device - constructor //------------------------------------------------- c64h156_device::c64h156_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t 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(nullptr), 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) { 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_clock_changed - called when the // device clock is altered in any way //------------------------------------------------- void c64h156_device::device_clock_changed() { m_period = attotime::from_hz(clock()); } //------------------------------------------------- // 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 = (machine().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 = (machine().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 = (machine().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(); } }