diff options
Diffstat (limited to 'src/devices/machine/swim3.cpp')
-rw-r--r-- | src/devices/machine/swim3.cpp | 730 |
1 files changed, 730 insertions, 0 deletions
diff --git a/src/devices/machine/swim3.cpp b/src/devices/machine/swim3.cpp new file mode 100644 index 00000000000..129f0f4a261 --- /dev/null +++ b/src/devices/machine/swim3.cpp @@ -0,0 +1,730 @@ +// license:BSD-3-Clause +// copyright-holders:Olivier Galibert +/********************************************************************* + + Implementation of the Apple SWIM3 floppy disk controller + +*********************************************************************/ + +#include "emu.h" +#include "swim3.h" + +DEFINE_DEVICE_TYPE(SWIM3, swim3_device, "swim3", "Apple SWIM3 (Sander/Wozniak Integrated Machine) version 3 floppy controller") + +swim3_device::swim3_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) : + applefdintf_device(mconfig, SWIM3, tag, owner, clock), + m_irq_cb(*this), + m_drq_cb(*this) +{ +} + +void swim3_device::device_start() +{ + applefdintf_device::device_start(); + + m_timer = timer_alloc(FUNC(swim3_device::update), this); + + save_item(NAME(m_mode)); + save_item(NAME(m_setup)); + save_item(NAME(m_param)); + save_item(NAME(m_irq)); + save_item(NAME(m_imask)); + save_item(NAME(m_state)); + save_item(NAME(m_step)); + save_item(NAME(m_error)); + save_item(NAME(m_cur_track)); + save_item(NAME(m_cur_sector)); + save_item(NAME(m_cur_format)); + save_item(NAME(m_sect1)); + save_item(NAME(m_xfer)); + save_item(NAME(m_fifo)); + save_item(NAME(m_fifo_pos)); + save_item(NAME(m_drq_write)); +} + +void swim3_device::device_reset() +{ + applefdintf_device::device_reset(); + m_floppy = nullptr; + + m_cur_live.state = L_IDLE; + m_cur_live.tm = attotime::never; + + m_mode = 0x00; + m_setup = 0x00; + m_param = 0x77; + m_irq = 0; + m_imask = 0; + m_state = S_IDLE; + m_step = 0; + m_error = 0; + m_cur_track = 0; + m_cur_sector = 0; + m_cur_format = 0; + m_sect1 = 0xff; + m_xfer = 0; + + m_fifo[0] = m_fifo[1] = 0; + m_fifo_pos = 0; + m_drq_write = false; + + m_devsel_cb(0); + m_sel35_cb(true); + m_hdsel_cb(false); +} + +void swim3_device::set_floppy(floppy_image_device *floppy) +{ + if(m_floppy == floppy) + return; + + if(m_floppy) + m_floppy->setup_index_pulse_cb(floppy_image_device::index_pulse_cb()); + + logerror("floppy %s\n", floppy ? floppy->tag() : "-"); + + m_floppy = floppy; + update_phases(); + m_hdsel_cb((m_mode >> 5) & 1); + + if(m_floppy) + m_floppy->setup_index_pulse_cb(floppy_image_device::index_pulse_cb(&swim3_device::index_callback, this)); +} + +floppy_image_device *swim3_device::get_floppy() const +{ + return m_floppy; +} + +void swim3_device::show_mode() const +{ + logerror("mode%s%s hdsel=%c %c%s %c%c%s\n", + m_mode & 0x80 ? " step" : "", + m_mode & 0x40 ? " format" : "", + m_mode & 0x20 ? '1' : '0', + m_mode & 0x10 ? 'w' : 'r', + m_mode & 0x08 ? " go" : "", + m_mode & 0x04 ? 'b' : '-', + m_mode & 0x02 ? 'a' : '-', + m_mode & 0x01 ? " irq" : ""); + +} + +u8 swim3_device::read(offs_t offset) +{ + static const char *const names[] = { + "data", "timer", "error", "param", "phases", "setup", "?6", "handshake", + "interrupt", "step", "track", "sector", "format", "sect1", "xfer", "imask" + }; + + switch(offset) { + case 0x2: { // error + u8 r = m_error; + m_error = 0; + return r; + } + + case 0x3: // param + return m_param; + + case 0x4: // phases + return m_phases & 0xf; + + case 0x5: // setup + return m_setup; + + case 0x6: // mode + return m_mode; + + case 0x7: { // handshake + u8 h = 0; + if(!m_floppy || m_floppy->wpt_r()) + h |= 0x0c; + logerror("hand %02x\n", h); + return h; + }; + + case 0x8: { + u8 res = m_irq; + m_irq = 0; + update_irq(); + return res; + } + + case 0xa: + return m_cur_track; + + case 0xb: + return m_cur_sector; + + case 0xc: + return m_cur_format; + + case 0xd: + return m_sect1; + + case 0xe: + return m_xfer; + + case 0xf: + return m_imask; + + default: + logerror("read %s\n", names[offset & 15]); + break; + } + return 0xff; +} + +void swim3_device::write(offs_t offset, u8 data) +{ + u8 prev_mode = m_mode; + + static const char *const names[] = { + "data", "timer", "error", "param", "phases", "setup", "mode0", "mode1", + "?8", "step", "track", "sector", "gap", "sect1", "xfer", "imask" + }; + switch(offset) { + case 0x3: // param + m_param = data; + logerror("precompensation late=%x early=%x\n", m_param >> 4, m_param & 0xf); + break; + + case 0x4: { // phases + m_phases = data | 0xf0; + update_phases(); + break; + } + + case 0x5: // setup + m_setup = data; + m_sel35_cb((m_setup >> 1) & 1); + logerror("setup write=%s %s nogcrconv=%s %s %s%s %s\n", + m_setup & 0x40 ? "gcr" : "mfm", + m_setup & 0x20 ? "ibm" : "apple", + m_setup & 0x10 ? "on" : "off", + m_setup & 0x08 ? "fclk/2" : "fclk", + m_setup & 0x04 ? "gcr" : "mfm", + m_setup & 0x02 ? " copy" : "", + m_setup & 0x01 ? "wrinvert" : "wrdirect"); + break; + + case 0x6: // mode clear + m_mode &= ~data; + show_mode(); + break; + + case 0x7: // mode set + m_mode |= data; + show_mode(); + break; + + case 0x9: // step + logerror("load step %02x\n", data); + m_step = data; + break; + + case 0xc: + m_gap = data; + break; + + case 0xd: + m_sect1 = data; + break; + + case 0xe: + m_xfer = data; + break; + + case 0xf: + m_imask = data; + logerror("imask%s%s%s%s%s\n", + m_imask & 0x10 ? " sense" : " -", + m_imask & 0x08 ? " sector" : " -", + m_imask & 0x04 ? " id" : " -", + m_imask & 0x02 ? " step" : " -", + m_imask & 0x01 ? " timer" : " -"); + update_irq(); + break; + + default: + logerror("write %s, %02x\n", names[offset], data); + break; + } + + if((m_mode ^ prev_mode) & 0x86) + m_devsel_cb((m_mode >> 1) & 3); + if((m_mode ^ prev_mode) & 0x20) + m_hdsel_cb((m_mode >> 5) & 1); + + if((m_mode & 0x80) && m_state == S_IDLE) { + logerror("%s stepping start count=%02x floppy=%s\n", machine().time().to_string(), m_step, m_floppy ? m_floppy->tag() : "-"); + m_state = S_STEP; + run(false, false); + } + + if((m_mode & 0x08) && m_state == S_IDLE) { + logerror("%s read start %s %s s1=%02x xfer=%d floppy=%s\n", machine().time().to_string(), m_setup & 0x04 ? "gcr" : "mfm", m_setup & 0x08 ? "fclk/2" : "fclk", m_sect1, m_xfer, m_floppy ? m_floppy->tag() : "-"); + m_state = S_ID; + run(false, false); + } + + if(!(m_mode & 0x88) && m_state != S_IDLE) { + logerror("%s read/step stopped\n", machine().time().to_string()); + m_drq_write = false; + live_abort(); + m_state = S_IDLE; + } +} + +void swim3_device::update_irq() +{ + logerror("irq %02x m %02x -> %02x\n", m_irq, m_imask, m_irq & m_imask); + m_irq_cb((m_irq & m_imask) != 0); +} + +void swim3_device::update_drq() +{ + if(m_drq_write) + m_drq_cb(m_fifo_pos != 2); + else + m_drq_cb(m_fifo_pos != 0); +} + +void swim3_device::index_callback(floppy_image_device *floppy, int state) +{ + if(state) { + sync(); + run(false, true); + } +} + +TIMER_CALLBACK_MEMBER(swim3_device::update) +{ + sync(); + run(true, false); +} + +void swim3_device::delay(int cycles) +{ + m_timer->adjust(attotime::from_ticks(cycles, clock())); +} + +void swim3_device::run(bool timeout, bool index) +{ + for(;;) { + if(m_cur_live.state != L_IDLE) { + live_run(); + if(m_cur_live.state != L_IDLE) + return; + } + + switch(m_state) { + case S_IDLE: + return; + + case S_STEP: + if(!m_step) { + m_state = S_STEP_DONE; + break; + } + + m_phases ^= 8; + update_phases(); + m_state = S_STEP_1; + delay(4); + break; + + case S_STEP_1: + if(!timeout) + return; + + m_phases ^= 8; + update_phases(); + m_state = S_STEP_0; + delay(2502); + break; + + case S_STEP_0: + if(!timeout) + return; + + m_step --; + m_state = S_STEP; + break; + + case S_STEP_DONE: + m_state = S_IDLE; + m_mode &= 0x7f; + m_irq |= 0x02; + update_irq(); + break; + + case S_ID: + live_start(m_setup & 0x04 ? L_GCR_SEARCH_ID : L_MFM_SEARCH_ID); + return; + } + } +} + +void swim3_device::checkpoint() +{ + m_cur_live.pll.commit(m_floppy, m_cur_live.tm); + m_checkpoint_live = m_cur_live; +} + +void swim3_device::rollback() +{ + m_cur_live = m_checkpoint_live; +} + +void swim3_device::live_delay(int state) +{ + m_cur_live.next_state = state; + m_timer->adjust(m_cur_live.tm - machine().time()); +} + +void swim3_device::sync() +{ + if(m_cur_live.state != L_IDLE && !m_cur_live.tm.is_never()) { + if(m_cur_live.tm > machine().time()) { + if(0) + logerror("%s: Rolling back and replaying (%s)\n", machine().time().to_string(), m_cur_live.tm.to_string()); + rollback(); + live_run(machine().time()); + m_cur_live.pll.commit(m_floppy, m_cur_live.tm); + } else { + if(0) + logerror("%s: Committing (%s)\n", machine().time().to_string(), m_cur_live.tm.to_string()); + m_cur_live.pll.commit(m_floppy, m_cur_live.tm); + if(m_cur_live.next_state != -1) { + m_cur_live.state = m_cur_live.next_state; + m_cur_live.next_state = -1; + } + if(m_cur_live.state == L_IDLE) { + m_cur_live.pll.stop_writing(m_floppy, m_cur_live.tm); + m_cur_live.tm = attotime::never; + } + } + m_cur_live.next_state = -1; + checkpoint(); + } +} + + +void swim3_device::live_abort() +{ + if(!m_cur_live.tm.is_never() && m_cur_live.tm > machine().time()) { + rollback(); + live_run(machine().time()); + } + + m_cur_live.pll.stop_writing(m_floppy, m_cur_live.tm); + m_cur_live.tm = attotime::never; + m_cur_live.state = L_IDLE; + m_cur_live.next_state = -1; +} + +bool swim3_device::read_one_bit(const attotime &limit) +{ + int bit = m_cur_live.pll.get_next_bit(m_cur_live.tm, m_floppy, limit); + if(bit < 0) + return true; + m_cur_live.shift_reg = (m_cur_live.shift_reg << 1) | bit; + m_cur_live.bit_counter++; + if(m_cur_live.data_separator_phase) { + m_cur_live.data_reg = (m_cur_live.data_reg << 1) | bit; + if((m_cur_live.crc ^ (bit ? 0x8000 : 0x0000)) & 0x8000) + m_cur_live.crc = (m_cur_live.crc << 1) ^ 0x1021; + else + m_cur_live.crc = m_cur_live.crc << 1; + } + m_cur_live.data_separator_phase = !m_cur_live.data_separator_phase; + return false; +} + +bool swim3_device::write_one_bit(const attotime &limit) +{ + bool bit = m_cur_live.shift_reg & 0x8000; + if(m_cur_live.pll.write_next_bit(bit, m_cur_live.tm, m_floppy, limit)) + return true; + if(m_cur_live.bit_counter & 1) { + if((m_cur_live.crc ^ (bit ? 0x8000 : 0x0000)) & 0x8000) + m_cur_live.crc = (m_cur_live.crc << 1) ^ 0x1021; + else + m_cur_live.crc = m_cur_live.crc << 1; + } + m_cur_live.shift_reg = m_cur_live.shift_reg << 1; + m_cur_live.bit_counter--; + return false; +} + + +void swim3_device::live_start(int state, bool start_writing) +{ + m_cur_live.tm = machine().time(); + m_cur_live.state = state; + m_cur_live.next_state = -1; + m_cur_live.shift_reg = 0; + m_cur_live.crc = 0xffff; + m_cur_live.bit_counter = 0; + m_cur_live.data_separator_phase = false; + m_cur_live.data_reg = 0; + + static const int cycles_per_cell[4] = { 16, 31, 31, 63 }; + m_cur_live.pll.reset(m_cur_live.tm); + m_cur_live.pll.set_clock(attotime::from_ticks(cycles_per_cell[(m_setup >> 2) & 3], clock())); + if(start_writing) + m_cur_live.pll.start_writing(machine().time()); + + logerror("PLL %s clock %s\n", start_writing ? "write" : "read", attotime::from_ticks(cycles_per_cell[(m_setup >> 2) & 3], clock()).to_string()); + + m_checkpoint_live = m_cur_live; + + live_run(); +} + +u8 swim3_device::dma_r() +{ + if(m_fifo_pos == 0) { + m_error |= 0x04; + live_abort(); + m_state = S_IDLE; + return 0; + } + u8 r = m_fifo[0]; + m_fifo[0] = m_fifo[1]; + m_fifo_pos--; + update_drq(); + return r; +} + +void swim3_device::fifo_push(u8 data) +{ + if(m_fifo_pos == 2) { + m_error |= 0x01; + live_abort(); + m_state = S_IDLE; + } else { + m_fifo[m_fifo_pos++] = data; + update_drq(); + } +} + +void swim3_device::live_run(attotime limit) +{ + if(m_cur_live.state == L_IDLE || m_cur_live.next_state != -1) + return; + + if(limit == attotime::never) { + if(m_floppy) + limit = m_floppy->time_next_index(); + if(limit == attotime::never) { + // Happens when there's no disk or if the swim3 is not + // connected to a drive, hence no index pulse. Force a + // sync from time to time in that case, so that the main + // cpu timeout isn't too painful. Avoids looping into + // infinity looking for data too. + + limit = machine().time() + attotime::from_msec(1); + m_timer->adjust(attotime::from_msec(1)); + } + } + + for(;;) { + switch(m_cur_live.state) { + case L_MFM_SEARCH_ID: + if(read_one_bit(limit)) + return; + + if((m_cur_live.bit_counter & 1) != (m_cur_live.shift_reg & 1)) { + if(m_cur_live.bit_counter < 64) { + m_cur_live.bit_counter = 0; + m_cur_live.data_separator_phase = false; + } else { + m_cur_live.bit_counter = 1; + m_cur_live.state = L_MFM_SCAN_ID; + break; + } + } + if(!(m_cur_live.bit_counter & 1)) + m_cur_live.crc = 0xffff; + + // logerror("pre counter %02d sr %04x data %02x crc %04x\n", m_cur_live.bit_counter, m_cur_live.shift_reg, m_cur_live.data_reg, m_cur_live.crc); + break; + + case L_MFM_SCAN_ID: + if(read_one_bit(limit)) + return; + if((m_cur_live.bit_counter == 16 || m_cur_live.bit_counter == 32 || m_cur_live.bit_counter == 48) && m_cur_live.shift_reg != 0x4489) { + m_cur_live.bit_counter = 0; + m_cur_live.state = L_MFM_SEARCH_ID; + break; + } + if(m_cur_live.bit_counter == 64 && m_cur_live.shift_reg != 0x5554) { // fe + m_cur_live.bit_counter = 0; + m_cur_live.state = L_MFM_SEARCH_ID; + break; + } + + if(m_cur_live.bit_counter == 64) { + m_cur_live.bit_counter = 0; + live_delay(L_MFM_READ_ID); + return; + } + + // logerror("post counter %02d sr %04x data %02x crc %04x\n", m_cur_live.bit_counter, m_cur_live.shift_reg, m_cur_live.data_reg, m_cur_live.crc); + break; + + case L_MFM_READ_ID: + if(!m_cur_live.bit_counter) + m_cur_sector &= 0x7f; + + if(read_one_bit(limit)) + return; + + if(!(m_cur_live.bit_counter & 0xf)) { + live_delay(L_MFM_READ_ID_BYTE); + return; + } + break; + + case L_MFM_READ_ID_BYTE: + m_cur_live.state = L_MFM_READ_ID; + switch(m_cur_live.bit_counter >> 4) { + case 1: + m_cur_track = m_cur_live.data_reg & 0x7f; + break; + case 2: + m_cur_track |= (m_cur_live.data_reg & 1) << 7; + break; + case 3: + m_cur_sector = m_cur_live.data_reg & 0x3f; + break; + case 4: + m_cur_format = m_cur_live.data_reg; + break; + case 6: + m_cur_live.bit_counter = 0; + m_cur_live.state = L_MFM_SEARCH_ID; + if(m_cur_live.crc == 0) { + logerror("sector id found, track=%02d head=%d sector=%02d\n", m_cur_track & 0x7f, m_cur_track >> 7, m_cur_sector & 0x3f); + m_cur_sector |= 0x80; + m_irq |= 0x04; + update_irq(); + if(!(m_sect1 & 0x80) && ((m_sect1 & 0x40) || (m_sect1 & 0x3f) == (m_cur_sector & 0x3f))) { + logerror("sector matches, reading data\n"); + m_cur_live.state = L_MFM_SEARCH_DATA; + } + } else { + checkpoint(); + m_error |= 0x40; + live_abort(); + m_state = S_IDLE; + return; + } + checkpoint(); + break; + } + break; + + case L_MFM_SEARCH_DATA: + if(read_one_bit(limit)) + return; + + if((m_cur_live.bit_counter & 1) != (m_cur_live.shift_reg & 1)) { + if(m_cur_live.bit_counter < 64) { + m_cur_live.bit_counter = 0; + m_cur_live.data_separator_phase = false; + } else { + m_cur_live.bit_counter = 1; + m_cur_live.state = L_MFM_SCAN_DATA; + break; + } + } + if(!(m_cur_live.bit_counter & 1)) + m_cur_live.crc = 0xffff; + + // logerror("pre counter %02d sr %04x data %02x crc %04x\n", m_cur_live.bit_counter, m_cur_live.shift_reg, m_cur_live.data_reg, m_cur_live.crc); + break; + + case L_MFM_SCAN_DATA: + if(read_one_bit(limit)) + return; + if((m_cur_live.bit_counter == 16 || m_cur_live.bit_counter == 32 || m_cur_live.bit_counter == 48) && m_cur_live.shift_reg != 0x4489) { + m_cur_live.bit_counter = 0; + m_cur_live.state = L_MFM_SEARCH_DATA; + break; + } + + if(m_cur_live.bit_counter == 64 && m_cur_live.shift_reg != 0x5545) { // fb + m_cur_live.bit_counter = 0; + m_cur_live.state = L_MFM_SEARCH_DATA; + break; + } + + if(m_cur_live.bit_counter == 64) { + m_cur_live.bit_counter = 0; + live_delay(L_MFM_READ_DATA); + return; + } + + // logerror("post counter %02d sr %04x data %02x crc %04x\n", m_cur_live.bit_counter, m_cur_live.shift_reg, m_cur_live.data_reg, m_cur_live.crc); + break; + + case L_MFM_READ_DATA: + if(!m_cur_live.bit_counter) + m_cur_sector &= 0x7f; + + if(read_one_bit(limit)) + return; + + if(!(m_cur_live.bit_counter & 0xf)) { + live_delay(L_MFM_READ_DATA_BYTE); + return; + } + break; + + case L_MFM_READ_DATA_BYTE: + m_cur_live.state = L_MFM_READ_DATA; + + if(m_cur_live.bit_counter <= 512*16) { + fifo_push(m_cur_live.data_reg); + if(m_error) + return; + } + + if(m_cur_live.bit_counter == 514*16) { + if(m_cur_live.crc == 0) { + logerror("sector read done, crc ok\n"); + m_xfer --; + if(m_xfer == 0) { + m_irq |= 0x08; + m_mode &= ~8; + live_abort(); + m_state = S_IDLE; + update_irq(); + return; + } + + m_cur_live.state = L_MFM_SEARCH_DATA; + + } else { + checkpoint(); + m_error |= 0x80; + m_mode &= ~8; + live_abort(); + m_state = S_IDLE; + return; + } + checkpoint(); + break; + } + break; + + case L_GCR_SEARCH_ID: + logerror("gcr search id\n"); + exit(0); + } + } +} |