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mirror of https://github.com/TomHarte/CLK.git synced 2024-12-27 01:31:42 +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 2016-09-08 07:41:26 -04:00
parent 2b053436e5
commit 1e7b5330f5
2 changed files with 240 additions and 252 deletions

View File

@ -9,6 +9,7 @@
#include "TapeUEF.hpp" #include "TapeUEF.hpp"
#include <cstring> #include <cstring>
#include <cstdio> #include <cstdio>
#include <cstdlib>
#include <cmath> #include <cmath>
using namespace Storage::Tape; using namespace Storage::Tape;
@ -44,10 +45,31 @@ static float gzgetfloat(gzFile file)
return result; 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) : UEF::UEF(const char *file_name) :
_chunk_id(0), _chunk_length(0), _chunk_position(0),
_time_base(1200), _time_base(1200),
_is_at_end(false) _is_at_end(false),
_pulse_pointer(0)
{ {
_file = gzopen(file_name, "rb"); _file = gzopen(file_name, "rb");
@ -67,8 +89,7 @@ UEF::UEF(const char *file_name) :
throw ErrorNotUEF; throw ErrorNotUEF;
} }
_start_of_next_chunk = gztell(_file); parse_next_tape_chunk();
find_next_tape_chunk();
} }
UEF::~UEF() UEF::~UEF()
@ -76,12 +97,13 @@ UEF::~UEF()
gzclose(_file); gzclose(_file);
} }
#pragma mark - Public methods
void UEF::reset() void UEF::reset()
{ {
gzseek(_file, 12, SEEK_SET); gzseek(_file, 12, SEEK_SET);
_is_at_end = false; _is_at_end = false;
_start_of_next_chunk = gztell(_file); parse_next_tape_chunk();
find_next_tape_chunk();
} }
bool UEF::is_at_end() bool UEF::is_at_end()
@ -101,119 +123,29 @@ Storage::Tape::Tape::Pulse UEF::get_next_pulse()
return 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; return next_pulse;
} }
void UEF::find_next_tape_chunk() #pragma mark - Chunk navigator
void UEF::parse_next_tape_chunk()
{ {
_chunk_position = 0; while(!_queued_pulses.size())
_bit_position = 0;
while(1)
{ {
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 // figure out where the next chunk will start
_chunk_id = (uint16_t)gzgetc(_file); z_off_t start_of_next_chunk = gztell(_file) + chunk_length;
_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;
if(gzeof(_file)) if(gzeof(_file))
{ {
@ -221,55 +153,18 @@ void UEF::find_next_tape_chunk()
return; return;
} }
switch(_chunk_id) switch(chunk_id)
{ {
case 0x0100: // implicit bit pattern case 0x0100: queue_implicit_bit_pattern(chunk_length); break;
_implicit_data_chunk.position = 0; case 0x0102: queue_explicit_bit_pattern(chunk_length); break;
return; case 0x0112: queue_integer_gap(); break;
case 0x0116: queue_floating_point_gap(); break;
case 0x0102: // explicit bit patterns case 0x0110: queue_carrier_tone(); break;
_explicit_data_chunk.position = 0; case 0x0111: queue_carrier_tone_with_dummy(); break;
return;
case 0x0112: // integer gap case 0x0114: queue_security_cycles(); break;
_chunk_duration.length = (uint16_t)gzgetc(_file); case 0x0104: queue_defined_data(chunk_length); break;
_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 0x113: // change of base rate case 0x113: // change of base rate
{ {
@ -280,80 +175,187 @@ void UEF::find_next_tape_chunk()
break; break;
default: default:
printf("!!! Skipping %04x\n", _chunk_id); printf("!!! Skipping %04x\n", chunk_id);
gzseek(_file, _chunk_length, SEEK_CUR);
break; 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; queue_implicit_byte((uint8_t)gzgetc(_file));
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;
} }
} }
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: if(!(bit&7)) current_byte = (uint8_t)gzgetc(_file);
queue_bit(current_byte&1);
current_byte >>= 1;
}
}
void UEF::queue_integer_gap()
{ {
uint32_t bit_position = _implicit_data_chunk.position%10; Time duration;
_implicit_data_chunk.position++; duration.length = (unsigned int)gzget16(_file);
if(!bit_position) _implicit_data_chunk.current_byte = (uint8_t)gzgetc(_file); duration.clock_rate = _time_base;
if(bit_position == 0) return false; _queued_pulses.emplace_back(Pulse::Zero, duration);
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: void UEF::queue_floating_point_gap()
{ {
uint32_t bit_position = _explicit_data_chunk.position%8; float length = gzgetfloat(_file);
_explicit_data_chunk.position++; Time duration;
if(!bit_position) _explicit_data_chunk.current_byte = (uint8_t)gzgetc(_file); duration.length = (unsigned int)(length * 4000000);
bool result = (_explicit_data_chunk.current_byte&1) ? true : false; duration.clock_rate = 4000000;
_explicit_data_chunk.current_byte >>= 1; _queued_pulses.emplace_back(Pulse::Zero, duration);
return result;
} }
break;
// TODO: 0x0104 void UEF::queue_carrier_tone()
case 0x0114:
{ {
uint32_t bit_position = _chunk_position%8; unsigned int number_of_cycles = (unsigned int)gzget16(_file);
_chunk_position++; while(number_of_cycles--) queue_bit(1);
if(!bit_position && _chunk_position < _chunk_duration.length) }
void UEF::queue_carrier_tone_with_dummy()
{ {
_current_byte = (uint8_t)gzgetc(_file); 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);
} }
bool result = (_current_byte&1) ? true : false;
_current_byte >>= 1;
return result;
}
break;
case 0x0111: 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';
case 0x0110: uint8_t current_byte = 0;
_chunk_position++; for(int cycle = 0; cycle < number_of_cycles; cycle++)
return true; {
if(!(cycle&7)) current_byte = (uint8_t)gzgetc(_file);
int bit = (current_byte >> 7);
current_byte <<= 1;
default: return true; 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);
} }
} }

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@ -11,7 +11,8 @@
#include "../Tape.hpp" #include "../Tape.hpp"
#include <zlib.h> #include <zlib.h>
#include <stdint.h> #include <cstdint>
#include <vector>
namespace Storage { namespace Storage {
namespace Tape { namespace Tape {
@ -41,42 +42,27 @@ class UEF : public Tape {
private: private:
gzFile _file; gzFile _file;
unsigned int _time_base; 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 _is_at_end;
bool _current_bit; std::vector<Pulse> _queued_pulses;
uint32_t _bit_position; size_t _pulse_pointer;
Time _chunk_duration; void parse_next_tape_chunk();
bool _first_is_pulse; void queue_implicit_bit_pattern(uint32_t length);
bool _last_is_pulse; void queue_explicit_bit_pattern(uint32_t length);
void find_next_tape_chunk(); void queue_integer_gap();
bool get_next_bit(); void queue_floating_point_gap();
bool chunk_is_finished();
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);
}; };
} }