mirror of
https://github.com/TomHarte/CLK.git
synced 2024-07-02 20:30:00 +00:00
More or less rewrote, to use a filled-per-chunk buffer of upcoming pulses rather than working them out as requests come. Which is more straightforward — all the code for a particular chunk goes in exactly one place — and much easier to extend. So threw in a provisional 0104 implementation.
This commit is contained in:
Thomas Harte
parent
2b053436e5
commit
1e7b5330f5
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@ -9,6 +9,7 @@
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#include "TapeUEF.hpp"
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#include <cstring>
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#include <cstdio>
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#include <cstdlib>
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#include <cmath>
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using namespace Storage::Tape;
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@ -44,10 +45,31 @@ static float gzgetfloat(gzFile file)
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return result;
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}
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static int gzget16(gzFile file)
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{
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int result = gzgetc(file);
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result |= (gzgetc(file) << 8);
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return result;
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}
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static int gzget24(gzFile file)
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{
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int result = gzget16(file);
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result |= (gzgetc(file) << 16);
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return result;
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}
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static int gzget32(gzFile file)
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{
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int result = gzget16(file);
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result |= (gzget16(file) << 16);
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return result;
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}
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UEF::UEF(const char *file_name) :
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_chunk_id(0), _chunk_length(0), _chunk_position(0),
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_time_base(1200),
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_is_at_end(false)
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_is_at_end(false),
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_pulse_pointer(0)
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{
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_file = gzopen(file_name, "rb");
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@ -67,8 +89,7 @@ UEF::UEF(const char *file_name) :
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throw ErrorNotUEF;
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}
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_start_of_next_chunk = gztell(_file);
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find_next_tape_chunk();
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parse_next_tape_chunk();
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}
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UEF::~UEF()
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@ -76,12 +97,13 @@ UEF::~UEF()
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gzclose(_file);
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}
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#pragma mark - Public methods
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void UEF::reset()
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{
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gzseek(_file, 12, SEEK_SET);
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_is_at_end = false;
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_start_of_next_chunk = gztell(_file);
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find_next_tape_chunk();
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parse_next_tape_chunk();
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}
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bool UEF::is_at_end()
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@ -101,119 +123,29 @@ Storage::Tape::Tape::Pulse UEF::get_next_pulse()
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return next_pulse;
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}
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if(!_bit_position && chunk_is_finished())
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next_pulse = _queued_pulses[_pulse_pointer];
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_pulse_pointer++;
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if(_pulse_pointer == _queued_pulses.size())
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{
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find_next_tape_chunk();
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_queued_pulses.clear();
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_pulse_pointer = 0;
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parse_next_tape_chunk();
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}
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switch(_chunk_id)
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{
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case 0x0100: case 0x0102:
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// In the ordinary ("1200 baud") data encoding format,
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// a zero bit is encoded as one complete cycle at the base frequency.
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// A one bit is two complete cycles at twice the base frequency.
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if(!_bit_position)
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{
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_current_bit = get_next_bit();
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}
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next_pulse.type = (_bit_position&1) ? Pulse::High : Pulse::Low;
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next_pulse.length.length = _current_bit ? 1 : 2;
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next_pulse.length.clock_rate = _time_base * 4;
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_bit_position = (_bit_position+1)&(_current_bit ? 3 : 1);
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break;
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case 0x0111:
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if(_chunk_position < _high_tone_with_dummy.pre_length || _chunk_position >= _high_tone_with_dummy.pre_length+10)
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{
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next_pulse.type = (_bit_position&1) ? Pulse::High : Pulse::Low;
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next_pulse.length.length = 1;
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next_pulse.length.clock_rate = _time_base * 4;
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_bit_position ^= 1;
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if(!_bit_position) _chunk_position++;
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}
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else
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{
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// to output 0xaa: 0
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if(!_bit_position)
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{
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_current_bit = (0x354 >> (_chunk_position - _high_tone_with_dummy.pre_length))&1;
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}
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next_pulse.type = (_bit_position&1) ? Pulse::High : Pulse::Low;
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next_pulse.length.length = _current_bit ? 1 : 2;
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next_pulse.length.clock_rate = _time_base * 4;
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_bit_position = (_bit_position+1)&(_current_bit ? 3 : 1);
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if(!_bit_position)
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{
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_chunk_position++;
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}
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}
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break;
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case 0x0110:
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next_pulse.type = (_bit_position&1) ? Pulse::High : Pulse::Low;
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next_pulse.length.length = 1;
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next_pulse.length.clock_rate = _time_base * 4;
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_bit_position ^= 1;
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if(!_bit_position) _chunk_position++;
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break;
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case 0x0114:
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if(!_bit_position)
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{
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_current_bit = get_next_bit();
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if(_first_is_pulse && !_chunk_position)
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{
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_bit_position++;
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}
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}
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next_pulse.type = (_bit_position&1) ? Pulse::High : Pulse::Low;
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next_pulse.length.length = _current_bit ? 1 : 2;
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next_pulse.length.clock_rate = _time_base * 4;
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_bit_position ^= 1;
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if((_chunk_id == 0x0114) && (_chunk_position == _chunk_duration.length-1) && _last_is_pulse)
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{
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_chunk_position++;
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}
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break;
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case 0x0112:
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case 0x0116:
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next_pulse.type = Pulse::Zero;
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next_pulse.length = _chunk_duration;
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_chunk_position++;
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break;
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}
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return next_pulse;
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}
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void UEF::find_next_tape_chunk()
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#pragma mark - Chunk navigator
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void UEF::parse_next_tape_chunk()
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{
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_chunk_position = 0;
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_bit_position = 0;
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while(1)
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while(!_queued_pulses.size())
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{
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gzseek(_file, _start_of_next_chunk, SEEK_SET);
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// read chunk details
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uint16_t chunk_id = (uint16_t)gzget16(_file);
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uint32_t chunk_length = (uint32_t)gzget32(_file);
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// read chunk ID
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_chunk_id = (uint16_t)gzgetc(_file);
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_chunk_id |= (uint16_t)(gzgetc(_file) << 8);
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_chunk_length = (uint32_t)(gzgetc(_file) << 0);
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_chunk_length |= (uint32_t)(gzgetc(_file) << 8);
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_chunk_length |= (uint32_t)(gzgetc(_file) << 16);
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_chunk_length |= (uint32_t)(gzgetc(_file) << 24);
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_start_of_next_chunk = gztell(_file) + _chunk_length;
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// figure out where the next chunk will start
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z_off_t start_of_next_chunk = gztell(_file) + chunk_length;
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if(gzeof(_file))
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{
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@ -221,55 +153,18 @@ void UEF::find_next_tape_chunk()
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return;
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}
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switch(_chunk_id)
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switch(chunk_id)
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{
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case 0x0100: // implicit bit pattern
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_implicit_data_chunk.position = 0;
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return;
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case 0x0100: queue_implicit_bit_pattern(chunk_length); break;
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case 0x0102: queue_explicit_bit_pattern(chunk_length); break;
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case 0x0112: queue_integer_gap(); break;
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case 0x0116: queue_floating_point_gap(); break;
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case 0x0102: // explicit bit patterns
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_explicit_data_chunk.position = 0;
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return;
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case 0x0110: queue_carrier_tone(); break;
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case 0x0111: queue_carrier_tone_with_dummy(); break;
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case 0x0112: // integer gap
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_chunk_duration.length = (uint16_t)gzgetc(_file);
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_chunk_duration.length |= (uint16_t)(gzgetc(_file) << 8);
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_chunk_duration.clock_rate = _time_base;
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return;
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case 0x0116: // floating point gap
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{
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float length = gzgetfloat(_file);
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_chunk_duration.length = (unsigned int)(length * 4000000);
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_chunk_duration.clock_rate = 4000000;
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}
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return;
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case 0x0110: // carrier tone
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_chunk_duration.length = (uint16_t)gzgetc(_file);
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_chunk_duration.length |= (uint16_t)(gzgetc(_file) << 8);
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gzseek(_file, _chunk_length - 2, SEEK_CUR);
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return;
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case 0x0111: // carrier tone with dummy byte
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_high_tone_with_dummy.pre_length = (uint16_t)gzgetc(_file);
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_high_tone_with_dummy.pre_length |= (uint16_t)(gzgetc(_file) << 8);
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_high_tone_with_dummy.post_length = (uint16_t)gzgetc(_file);
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_high_tone_with_dummy.post_length |= (uint16_t)(gzgetc(_file) << 8);
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_chunk_duration.length = _high_tone_with_dummy.post_length + _high_tone_with_dummy.pre_length + 10;
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gzseek(_file, _chunk_length - 4, SEEK_CUR);
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return;
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case 0x0114: // security cycles
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{
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// read number of cycles
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_chunk_duration.length = (uint32_t)gzgetc(_file);
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_chunk_duration.length |= (uint32_t)gzgetc(_file) << 8;
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_chunk_duration.length |= (uint32_t)gzgetc(_file) << 16;
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// Ps and Ws
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_first_is_pulse = gzgetc(_file) == 'P';
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_last_is_pulse = gzgetc(_file) == 'P';
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}
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break;
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case 0x0114: queue_security_cycles(); break;
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case 0x0104: queue_defined_data(chunk_length); break;
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case 0x113: // change of base rate
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{
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@ -280,80 +175,187 @@ void UEF::find_next_tape_chunk()
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break;
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default:
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printf("!!! Skipping %04x\n", _chunk_id);
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gzseek(_file, _chunk_length, SEEK_CUR);
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printf("!!! Skipping %04x\n", chunk_id);
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break;
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}
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gzseek(_file, start_of_next_chunk, SEEK_SET);
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}
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}
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bool UEF::chunk_is_finished()
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#pragma mark - Chunk parsers
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void UEF::queue_implicit_bit_pattern(uint32_t length)
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{
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switch(_chunk_id)
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while(length--)
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{
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case 0x0100: return (_implicit_data_chunk.position / 10) == _chunk_length;
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case 0x0102: return (_explicit_data_chunk.position / 8) == _chunk_length;
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case 0x0114:
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case 0x0111:
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case 0x0110: return _chunk_position == _chunk_duration.length;
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case 0x0112:
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case 0x0116: return _chunk_position ? true : false;
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default: return true;
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queue_implicit_byte((uint8_t)gzgetc(_file));
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}
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}
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bool UEF::get_next_bit()
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void UEF::queue_explicit_bit_pattern(uint32_t length)
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{
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switch(_chunk_id)
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size_t length_in_bits = (length << 3) - (size_t)gzgetc(_file);
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uint8_t current_byte = 0;
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for(size_t bit = 0; bit < length_in_bits; bit++)
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{
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case 0x0100:
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{
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uint32_t bit_position = _implicit_data_chunk.position%10;
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_implicit_data_chunk.position++;
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if(!bit_position) _implicit_data_chunk.current_byte = (uint8_t)gzgetc(_file);
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if(bit_position == 0) return false;
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if(bit_position == 9) return true;
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bool result = (_implicit_data_chunk.current_byte&1) ? true : false;
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_implicit_data_chunk.current_byte >>= 1;
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return result;
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}
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break;
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case 0x0102:
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{
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uint32_t bit_position = _explicit_data_chunk.position%8;
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_explicit_data_chunk.position++;
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if(!bit_position) _explicit_data_chunk.current_byte = (uint8_t)gzgetc(_file);
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bool result = (_explicit_data_chunk.current_byte&1) ? true : false;
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_explicit_data_chunk.current_byte >>= 1;
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return result;
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}
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break;
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// TODO: 0x0104
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case 0x0114:
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{
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uint32_t bit_position = _chunk_position%8;
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_chunk_position++;
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if(!bit_position && _chunk_position < _chunk_duration.length)
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{
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_current_byte = (uint8_t)gzgetc(_file);
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}
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bool result = (_current_byte&1) ? true : false;
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_current_byte >>= 1;
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return result;
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}
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break;
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case 0x0111:
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case 0x0110:
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_chunk_position++;
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return true;
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default: return true;
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if(!(bit&7)) current_byte = (uint8_t)gzgetc(_file);
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queue_bit(current_byte&1);
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current_byte >>= 1;
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}
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}
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void UEF::queue_integer_gap()
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{
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Time duration;
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duration.length = (unsigned int)gzget16(_file);
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duration.clock_rate = _time_base;
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_queued_pulses.emplace_back(Pulse::Zero, duration);
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}
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void UEF::queue_floating_point_gap()
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{
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float length = gzgetfloat(_file);
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Time duration;
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duration.length = (unsigned int)(length * 4000000);
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duration.clock_rate = 4000000;
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_queued_pulses.emplace_back(Pulse::Zero, duration);
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}
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void UEF::queue_carrier_tone()
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{
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unsigned int number_of_cycles = (unsigned int)gzget16(_file);
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while(number_of_cycles--) queue_bit(1);
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}
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void UEF::queue_carrier_tone_with_dummy()
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{
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unsigned int pre_cycles = (unsigned int)gzget16(_file);
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unsigned int post_cycles = (unsigned int)gzget16(_file);
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while(pre_cycles--) queue_bit(1);
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queue_implicit_byte(0xaa);
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while(post_cycles--) queue_bit(1);
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}
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void UEF::queue_security_cycles()
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{
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int number_of_cycles = gzget24(_file);
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bool first_is_pulse = gzgetc(_file) == 'P';
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bool last_is_pulse = gzgetc(_file) == 'P';
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uint8_t current_byte = 0;
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for(int cycle = 0; cycle < number_of_cycles; cycle++)
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{
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if(!(cycle&7)) current_byte = (uint8_t)gzgetc(_file);
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int bit = (current_byte >> 7);
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current_byte <<= 1;
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Time duration;
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duration.length = bit ? 1 : 2;
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duration.clock_rate = _time_base * 4;
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if(!cycle && first_is_pulse)
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{
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_queued_pulses.emplace_back(Pulse::High, duration);
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}
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else if(cycle == number_of_cycles-1 && last_is_pulse)
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{
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_queued_pulses.emplace_back(Pulse::Low, duration);
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}
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else
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{
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_queued_pulses.emplace_back(Pulse::Low, duration);
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_queued_pulses.emplace_back(Pulse::High, duration);
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}
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}
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}
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void UEF::queue_defined_data(uint32_t length)
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{
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if(length < 3) return;
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int bits_per_packet = gzgetc(_file);
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char parity_type = (char)gzgetc(_file);
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int number_of_stop_bits = gzgetc(_file);
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bool has_extra_stop_wave = (number_of_stop_bits < 0);
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number_of_stop_bits = abs(number_of_stop_bits);
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length -= 3;
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while(length--)
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{
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uint8_t byte = (uint8_t)gzgetc(_file);
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uint8_t parity_value = byte;
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parity_value ^= (parity_value >> 4);
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parity_value ^= (parity_value >> 2);
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parity_value ^= (parity_value >> 1);
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queue_bit(0);
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int c = bits_per_packet;
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while(c--)
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{
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queue_bit(byte&1);
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byte >>= 1;
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}
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switch(parity_type)
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{
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default: break;
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case 'E': queue_bit(parity_value&1); break;
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case 'O': queue_bit((parity_value&1) ^ 1); break;
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}
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int stop_bits = number_of_stop_bits;
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while(stop_bits--) queue_bit(1);
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if(has_extra_stop_wave)
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{
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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);
|
||||
}
|
||||
}
|
||||
|
|
|
|||
|
|
@ -11,7 +11,8 @@
|
|||
|
||||
#include "../Tape.hpp"
|
||||
#include <zlib.h>
|
||||
#include <stdint.h>
|
||||
#include <cstdint>
|
||||
#include <vector>
|
||||
|
||||
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<Pulse> _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);
|
||||
};
|
||||
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user