From 1e7b5330f5c66e6c8a84576c38dd47c1e482f6fb Mon Sep 17 00:00:00 2001 From: Thomas Harte Date: Thu, 8 Sep 2016 07:41:26 -0400 Subject: [PATCH] =?UTF-8?q?More=20or=20less=20rewrote,=20to=20use=20a=20fi?= =?UTF-8?q?lled-per-chunk=20buffer=20of=20upcoming=20pulses=20rather=20tha?= =?UTF-8?q?n=20working=20them=20out=20as=20requests=20come.=20Which=20is?= =?UTF-8?q?=20more=20straightforward=20=E2=80=94=20all=20the=20code=20for?= =?UTF-8?q?=20a=20particular=20chunk=20goes=20in=20exactly=20one=20place?= =?UTF-8?q?=20=E2=80=94=20and=20much=20easier=20to=20extend.=20So=20threw?= =?UTF-8?q?=20in=20a=20provisional=200104=20implementation.?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- Storage/Tape/Formats/TapeUEF.cpp | 442 ++++++++++++++++--------------- Storage/Tape/Formats/TapeUEF.hpp | 50 ++-- 2 files changed, 240 insertions(+), 252 deletions(-) diff --git a/Storage/Tape/Formats/TapeUEF.cpp b/Storage/Tape/Formats/TapeUEF.cpp index 4db40f626..a0c74cf55 100644 --- a/Storage/Tape/Formats/TapeUEF.cpp +++ b/Storage/Tape/Formats/TapeUEF.cpp @@ -9,6 +9,7 @@ #include "TapeUEF.hpp" #include #include +#include #include using namespace Storage::Tape; @@ -44,10 +45,31 @@ static float gzgetfloat(gzFile file) return result; } +static int gzget16(gzFile file) +{ + int result = gzgetc(file); + result |= (gzgetc(file) << 8); + return result; +} + +static int gzget24(gzFile file) +{ + int result = gzget16(file); + result |= (gzgetc(file) << 16); + return result; +} + +static int gzget32(gzFile file) +{ + int result = gzget16(file); + result |= (gzget16(file) << 16); + return result; +} + UEF::UEF(const char *file_name) : - _chunk_id(0), _chunk_length(0), _chunk_position(0), _time_base(1200), - _is_at_end(false) + _is_at_end(false), + _pulse_pointer(0) { _file = gzopen(file_name, "rb"); @@ -67,8 +89,7 @@ UEF::UEF(const char *file_name) : throw ErrorNotUEF; } - _start_of_next_chunk = gztell(_file); - find_next_tape_chunk(); + parse_next_tape_chunk(); } UEF::~UEF() @@ -76,12 +97,13 @@ UEF::~UEF() gzclose(_file); } +#pragma mark - Public methods + void UEF::reset() { gzseek(_file, 12, SEEK_SET); _is_at_end = false; - _start_of_next_chunk = gztell(_file); - find_next_tape_chunk(); + parse_next_tape_chunk(); } bool UEF::is_at_end() @@ -101,119 +123,29 @@ Storage::Tape::Tape::Pulse UEF::get_next_pulse() return next_pulse; } - if(!_bit_position && chunk_is_finished()) + next_pulse = _queued_pulses[_pulse_pointer]; + _pulse_pointer++; + if(_pulse_pointer == _queued_pulses.size()) { - find_next_tape_chunk(); + _queued_pulses.clear(); + _pulse_pointer = 0; + parse_next_tape_chunk(); } - - switch(_chunk_id) - { - case 0x0100: case 0x0102: - // In the ordinary ("1200 baud") data encoding format, - // a zero bit is encoded as one complete cycle at the base frequency. - // A one bit is two complete cycles at twice the base frequency. - - if(!_bit_position) - { - _current_bit = get_next_bit(); - } - - next_pulse.type = (_bit_position&1) ? Pulse::High : Pulse::Low; - next_pulse.length.length = _current_bit ? 1 : 2; - next_pulse.length.clock_rate = _time_base * 4; - _bit_position = (_bit_position+1)&(_current_bit ? 3 : 1); - break; - - case 0x0111: - if(_chunk_position < _high_tone_with_dummy.pre_length || _chunk_position >= _high_tone_with_dummy.pre_length+10) - { - next_pulse.type = (_bit_position&1) ? Pulse::High : Pulse::Low; - next_pulse.length.length = 1; - next_pulse.length.clock_rate = _time_base * 4; - _bit_position ^= 1; - - if(!_bit_position) _chunk_position++; - } - else - { - // to output 0xaa: 0 - if(!_bit_position) - { - _current_bit = (0x354 >> (_chunk_position - _high_tone_with_dummy.pre_length))&1; - } - - next_pulse.type = (_bit_position&1) ? Pulse::High : Pulse::Low; - next_pulse.length.length = _current_bit ? 1 : 2; - next_pulse.length.clock_rate = _time_base * 4; - _bit_position = (_bit_position+1)&(_current_bit ? 3 : 1); - - if(!_bit_position) - { - _chunk_position++; - } - } - break; - - case 0x0110: - next_pulse.type = (_bit_position&1) ? Pulse::High : Pulse::Low; - next_pulse.length.length = 1; - next_pulse.length.clock_rate = _time_base * 4; - _bit_position ^= 1; - - if(!_bit_position) _chunk_position++; - break; - - case 0x0114: - if(!_bit_position) - { - _current_bit = get_next_bit(); - if(_first_is_pulse && !_chunk_position) - { - _bit_position++; - } - } - - next_pulse.type = (_bit_position&1) ? Pulse::High : Pulse::Low; - next_pulse.length.length = _current_bit ? 1 : 2; - next_pulse.length.clock_rate = _time_base * 4; - _bit_position ^= 1; - - if((_chunk_id == 0x0114) && (_chunk_position == _chunk_duration.length-1) && _last_is_pulse) - { - _chunk_position++; - } - break; - - case 0x0112: - case 0x0116: - next_pulse.type = Pulse::Zero; - next_pulse.length = _chunk_duration; - _chunk_position++; - break; - } - return next_pulse; } -void UEF::find_next_tape_chunk() +#pragma mark - Chunk navigator + +void UEF::parse_next_tape_chunk() { - _chunk_position = 0; - _bit_position = 0; - - while(1) + while(!_queued_pulses.size()) { - gzseek(_file, _start_of_next_chunk, SEEK_SET); + // read chunk details + uint16_t chunk_id = (uint16_t)gzget16(_file); + uint32_t chunk_length = (uint32_t)gzget32(_file); - // read chunk ID - _chunk_id = (uint16_t)gzgetc(_file); - _chunk_id |= (uint16_t)(gzgetc(_file) << 8); - - _chunk_length = (uint32_t)(gzgetc(_file) << 0); - _chunk_length |= (uint32_t)(gzgetc(_file) << 8); - _chunk_length |= (uint32_t)(gzgetc(_file) << 16); - _chunk_length |= (uint32_t)(gzgetc(_file) << 24); - - _start_of_next_chunk = gztell(_file) + _chunk_length; + // figure out where the next chunk will start + z_off_t start_of_next_chunk = gztell(_file) + chunk_length; if(gzeof(_file)) { @@ -221,55 +153,18 @@ void UEF::find_next_tape_chunk() return; } - switch(_chunk_id) + switch(chunk_id) { - case 0x0100: // implicit bit pattern - _implicit_data_chunk.position = 0; - return; + case 0x0100: queue_implicit_bit_pattern(chunk_length); break; + case 0x0102: queue_explicit_bit_pattern(chunk_length); break; + case 0x0112: queue_integer_gap(); break; + case 0x0116: queue_floating_point_gap(); break; - case 0x0102: // explicit bit patterns - _explicit_data_chunk.position = 0; - return; + case 0x0110: queue_carrier_tone(); break; + case 0x0111: queue_carrier_tone_with_dummy(); break; - case 0x0112: // integer gap - _chunk_duration.length = (uint16_t)gzgetc(_file); - _chunk_duration.length |= (uint16_t)(gzgetc(_file) << 8); - _chunk_duration.clock_rate = _time_base; - return; - - case 0x0116: // floating point gap - { - float length = gzgetfloat(_file); - _chunk_duration.length = (unsigned int)(length * 4000000); - _chunk_duration.clock_rate = 4000000; - } - return; - - case 0x0110: // carrier tone - _chunk_duration.length = (uint16_t)gzgetc(_file); - _chunk_duration.length |= (uint16_t)(gzgetc(_file) << 8); - gzseek(_file, _chunk_length - 2, SEEK_CUR); - return; - case 0x0111: // carrier tone with dummy byte - _high_tone_with_dummy.pre_length = (uint16_t)gzgetc(_file); - _high_tone_with_dummy.pre_length |= (uint16_t)(gzgetc(_file) << 8); - _high_tone_with_dummy.post_length = (uint16_t)gzgetc(_file); - _high_tone_with_dummy.post_length |= (uint16_t)(gzgetc(_file) << 8); - _chunk_duration.length = _high_tone_with_dummy.post_length + _high_tone_with_dummy.pre_length + 10; - gzseek(_file, _chunk_length - 4, SEEK_CUR); - return; - case 0x0114: // security cycles - { - // read number of cycles - _chunk_duration.length = (uint32_t)gzgetc(_file); - _chunk_duration.length |= (uint32_t)gzgetc(_file) << 8; - _chunk_duration.length |= (uint32_t)gzgetc(_file) << 16; - - // Ps and Ws - _first_is_pulse = gzgetc(_file) == 'P'; - _last_is_pulse = gzgetc(_file) == 'P'; - } - break; + case 0x0114: queue_security_cycles(); break; + case 0x0104: queue_defined_data(chunk_length); break; case 0x113: // change of base rate { @@ -280,80 +175,187 @@ void UEF::find_next_tape_chunk() break; default: - printf("!!! Skipping %04x\n", _chunk_id); - gzseek(_file, _chunk_length, SEEK_CUR); + printf("!!! Skipping %04x\n", chunk_id); break; } + + gzseek(_file, start_of_next_chunk, SEEK_SET); } } -bool UEF::chunk_is_finished() +#pragma mark - Chunk parsers + +void UEF::queue_implicit_bit_pattern(uint32_t length) { - switch(_chunk_id) + while(length--) { - case 0x0100: return (_implicit_data_chunk.position / 10) == _chunk_length; - case 0x0102: return (_explicit_data_chunk.position / 8) == _chunk_length; - case 0x0114: - case 0x0111: - case 0x0110: return _chunk_position == _chunk_duration.length; - - case 0x0112: - case 0x0116: return _chunk_position ? true : false; - - default: return true; + queue_implicit_byte((uint8_t)gzgetc(_file)); } } -bool UEF::get_next_bit() +void UEF::queue_explicit_bit_pattern(uint32_t length) { - switch(_chunk_id) + size_t length_in_bits = (length << 3) - (size_t)gzgetc(_file); + uint8_t current_byte = 0; + for(size_t bit = 0; bit < length_in_bits; bit++) { - case 0x0100: - { - uint32_t bit_position = _implicit_data_chunk.position%10; - _implicit_data_chunk.position++; - if(!bit_position) _implicit_data_chunk.current_byte = (uint8_t)gzgetc(_file); - if(bit_position == 0) return false; - if(bit_position == 9) return true; - bool result = (_implicit_data_chunk.current_byte&1) ? true : false; - _implicit_data_chunk.current_byte >>= 1; - return result; - } - break; - - case 0x0102: - { - uint32_t bit_position = _explicit_data_chunk.position%8; - _explicit_data_chunk.position++; - if(!bit_position) _explicit_data_chunk.current_byte = (uint8_t)gzgetc(_file); - bool result = (_explicit_data_chunk.current_byte&1) ? true : false; - _explicit_data_chunk.current_byte >>= 1; - return result; - } - break; - - // TODO: 0x0104 - - case 0x0114: - { - uint32_t bit_position = _chunk_position%8; - _chunk_position++; - if(!bit_position && _chunk_position < _chunk_duration.length) - { - _current_byte = (uint8_t)gzgetc(_file); - } - bool result = (_current_byte&1) ? true : false; - _current_byte >>= 1; - return result; - } - break; - - case 0x0111: - - case 0x0110: - _chunk_position++; - return true; - - default: return true; + if(!(bit&7)) current_byte = (uint8_t)gzgetc(_file); + queue_bit(current_byte&1); + current_byte >>= 1; + } +} + +void UEF::queue_integer_gap() +{ + Time duration; + duration.length = (unsigned int)gzget16(_file); + duration.clock_rate = _time_base; + _queued_pulses.emplace_back(Pulse::Zero, duration); +} + +void UEF::queue_floating_point_gap() +{ + float length = gzgetfloat(_file); + Time duration; + duration.length = (unsigned int)(length * 4000000); + duration.clock_rate = 4000000; + _queued_pulses.emplace_back(Pulse::Zero, duration); +} + +void UEF::queue_carrier_tone() +{ + unsigned int number_of_cycles = (unsigned int)gzget16(_file); + while(number_of_cycles--) queue_bit(1); +} + +void UEF::queue_carrier_tone_with_dummy() +{ + unsigned int pre_cycles = (unsigned int)gzget16(_file); + unsigned int post_cycles = (unsigned int)gzget16(_file); + while(pre_cycles--) queue_bit(1); + queue_implicit_byte(0xaa); + while(post_cycles--) queue_bit(1); +} + +void UEF::queue_security_cycles() +{ + int number_of_cycles = gzget24(_file); + bool first_is_pulse = gzgetc(_file) == 'P'; + bool last_is_pulse = gzgetc(_file) == 'P'; + + uint8_t current_byte = 0; + for(int cycle = 0; cycle < number_of_cycles; cycle++) + { + if(!(cycle&7)) current_byte = (uint8_t)gzgetc(_file); + int bit = (current_byte >> 7); + current_byte <<= 1; + + Time duration; + duration.length = bit ? 1 : 2; + duration.clock_rate = _time_base * 4; + + if(!cycle && first_is_pulse) + { + _queued_pulses.emplace_back(Pulse::High, duration); + } + else if(cycle == number_of_cycles-1 && last_is_pulse) + { + _queued_pulses.emplace_back(Pulse::Low, duration); + } + else + { + _queued_pulses.emplace_back(Pulse::Low, duration); + _queued_pulses.emplace_back(Pulse::High, duration); + } + } +} + +void UEF::queue_defined_data(uint32_t length) +{ + if(length < 3) return; + + int bits_per_packet = gzgetc(_file); + char parity_type = (char)gzgetc(_file); + int number_of_stop_bits = gzgetc(_file); + + bool has_extra_stop_wave = (number_of_stop_bits < 0); + number_of_stop_bits = abs(number_of_stop_bits); + + length -= 3; + while(length--) + { + uint8_t byte = (uint8_t)gzgetc(_file); + + uint8_t parity_value = byte; + parity_value ^= (parity_value >> 4); + parity_value ^= (parity_value >> 2); + parity_value ^= (parity_value >> 1); + + queue_bit(0); + int c = bits_per_packet; + while(c--) + { + queue_bit(byte&1); + byte >>= 1; + } + + switch(parity_type) + { + default: break; + case 'E': queue_bit(parity_value&1); break; + case 'O': queue_bit((parity_value&1) ^ 1); break; + } + + int stop_bits = number_of_stop_bits; + while(stop_bits--) queue_bit(1); + if(has_extra_stop_wave) + { + Time duration; + duration.length = 1; + duration.clock_rate = _time_base * 4; + _queued_pulses.emplace_back(Pulse::Low, duration); + _queued_pulses.emplace_back(Pulse::High, duration); + } + } +} + +#pragma mark - Queuing helpers + +void UEF::queue_implicit_byte(uint8_t byte) +{ + queue_bit(0); + int c = 8; + while(c--) + { + queue_bit(byte&1); + byte >>= 1; + } + queue_bit(1); +} + +void UEF::queue_bit(int bit) +{ + // TODO: allow for 300-baud encoding + if(bit) + { + // Encode a 1 as four high-frequency waves + Time duration; + duration.length = 1; + duration.clock_rate = _time_base * 4; + + _queued_pulses.emplace_back(Pulse::Low, duration); + _queued_pulses.emplace_back(Pulse::High, duration); + _queued_pulses.emplace_back(Pulse::Low, duration); + _queued_pulses.emplace_back(Pulse::High, duration); + } + else + { + // Encode a 0 as two low-frequency waves + Time duration; + duration.length = 2; + duration.clock_rate = _time_base * 4; + + _queued_pulses.emplace_back(Pulse::Low, duration); + _queued_pulses.emplace_back(Pulse::High, duration); } } diff --git a/Storage/Tape/Formats/TapeUEF.hpp b/Storage/Tape/Formats/TapeUEF.hpp index a4079b0fb..508d5d4dc 100644 --- a/Storage/Tape/Formats/TapeUEF.hpp +++ b/Storage/Tape/Formats/TapeUEF.hpp @@ -11,7 +11,8 @@ #include "../Tape.hpp" #include -#include +#include +#include namespace Storage { namespace Tape { @@ -41,42 +42,27 @@ class UEF : public Tape { private: gzFile _file; unsigned int _time_base; - z_off_t _start_of_next_chunk; - - uint16_t _chunk_id; - uint32_t _chunk_length; - - union { - struct { - uint8_t current_byte; - uint32_t position; - } _implicit_data_chunk; - - struct { - uint8_t current_byte; - uint32_t position; - } _explicit_data_chunk; - - struct { - unsigned int pre_length, post_length; - } _high_tone_with_dummy; - }; - - uint8_t _current_byte; - uint32_t _chunk_position; bool _is_at_end; - bool _current_bit; - uint32_t _bit_position; + std::vector _queued_pulses; + size_t _pulse_pointer; - Time _chunk_duration; + void parse_next_tape_chunk(); - bool _first_is_pulse; - bool _last_is_pulse; + void queue_implicit_bit_pattern(uint32_t length); + void queue_explicit_bit_pattern(uint32_t length); - void find_next_tape_chunk(); - bool get_next_bit(); - bool chunk_is_finished(); + void queue_integer_gap(); + void queue_floating_point_gap(); + + void queue_carrier_tone(); + void queue_carrier_tone_with_dummy(); + + void queue_security_cycles(); + void queue_defined_data(uint32_t length); + + void queue_bit(int bit); + void queue_implicit_byte(uint8_t byte); }; }