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CLK/StaticAnalyser/Commodore/Tape.cpp

442 lines
12 KiB
C++

//
// Tape.cpp
// Clock Signal
//
// Created by Thomas Harte on 24/08/2016.
// Copyright © 2016 Thomas Harte. All rights reserved.
//
#include "Tape.hpp"
#include "../TapeParser.hpp"
#include "Utilities.hpp"
using namespace StaticAnalyser::Commodore;
enum class WaveType {
Short, Medium, Long, Unrecognised
};
enum class SymbolType {
One, Zero, Word, EndOfBlock, LeadIn
};
struct Header {
enum {
RelocatableProgram,
NonRelocatableProgram,
DataSequenceHeader,
DataBlock,
EndOfTape,
Unknown
} type;
std::vector<uint8_t> data;
std::wstring name;
std::vector<uint8_t> raw_name;
uint16_t starting_address;
uint16_t ending_address;
bool parity_was_valid;
bool duplicate_matched;
};
struct Data {
std::vector<uint8_t> data;
bool parity_was_valid;
bool duplicate_matched;
};
class CommodoreROMTapeParser: public StaticAnalyer::TapeParser<WaveType, SymbolType> {
public:
CommodoreROMTapeParser(const std::shared_ptr<Storage::Tape::Tape> &tape) :
TapeParser(tape),
_wave_period(0.0f),
_previous_was_high(false),
_parity_byte(0) {}
/*!
Advances to the next block on the tape, treating it as a header, then consumes, parses, and returns it.
Returns @c nullptr if any wave-encoding level errors are encountered.
*/
std::unique_ptr<Header> get_next_header()
{
return duplicate_match<Header>(
get_next_header_body(true),
get_next_header_body(false)
);
}
/*!
Advances to the next block on the tape, treating it as data, then consumes, parses, and returns it.
Returns @c nullptr if any wave-encoding level errors are encountered.
*/
std::unique_ptr<Data> get_next_data()
{
return duplicate_match<Data>(
get_next_data_body(true),
get_next_data_body(false)
);
}
void spin()
{
while(!is_at_end())
{
SymbolType symbol = get_next_symbol();
switch(symbol)
{
case SymbolType::One: printf("1"); break;
case SymbolType::Zero: printf("0"); break;
case SymbolType::Word: printf(" "); break;
case SymbolType::EndOfBlock: printf("\n"); break;
case SymbolType::LeadIn: printf("-"); break;
}
}
}
private:
/*!
Template for the logic in selecting which of two copies of something to consider authoritative,
including setting the duplicate_matched flag.
*/
template<class ObjectType>
std::unique_ptr<ObjectType> duplicate_match(std::unique_ptr<ObjectType> first_copy, std::unique_ptr<ObjectType> second_copy)
{
// if only one copy was parsed successfully, return it
if(!first_copy) return second_copy;
if(!second_copy) return first_copy;
// if no copies were second_copy, return nullptr
if(!first_copy && !second_copy) return nullptr;
// otherwise plan to return either one with a correct check digit, doing a comparison with the other
std::unique_ptr<ObjectType> *copy_to_return = &first_copy;
if(!first_copy->parity_was_valid && second_copy->parity_was_valid) copy_to_return = &second_copy;
(*copy_to_return)->duplicate_matched = true;
if(first_copy->data.size() != second_copy->data.size())
(*copy_to_return)->duplicate_matched = false;
else
(*copy_to_return)->duplicate_matched = !(memcmp(&first_copy->data[0], &second_copy->data[0], first_copy->data.size()));
return std::move(*copy_to_return);
}
std::unique_ptr<Header> get_next_header_body(bool is_original)
{
std::unique_ptr<Header> header(new Header);
reset_error_flag();
// find and proceed beyond lead-in tone
proceed_to_symbol(SymbolType::LeadIn);
// look for landing zone
proceed_to_landing_zone(is_original);
reset_parity_byte();
// get header type
uint8_t header_type = get_next_byte();
switch(header_type)
{
default: header->type = Header::Unknown; break;
case 0x01: header->type = Header::RelocatableProgram; break;
case 0x02: header->type = Header::DataBlock; break;
case 0x03: header->type = Header::NonRelocatableProgram; break;
case 0x04: header->type = Header::DataSequenceHeader; break;
case 0x05: header->type = Header::EndOfTape; break;
}
// grab rest of data
header->data.reserve(191);
for(size_t c = 0; c < 191; c++)
{
header->data.push_back(get_next_byte());
}
uint8_t parity_byte = get_parity_byte();
header->parity_was_valid = get_next_byte() == parity_byte;
// parse if this is not pure data
if(header->type != Header::DataBlock)
{
header->starting_address = (uint16_t)(header->data[0] | (header->data[1] << 8));
header->ending_address = (uint16_t)(header->data[2] | (header->data[3] << 8));
for(size_t c = 0; c < 16; c++)
{
header->raw_name.push_back(header->data[4 + c]);
}
header->name = petscii_from_bytes(&header->raw_name[0], 16, false);
}
if(get_error_flag()) return nullptr;
return header;
}
std::unique_ptr<Data> get_next_data_body(bool is_original)
{
std::unique_ptr<Data> data(new Data);
reset_error_flag();
// find and proceed beyond lead-in tone to the next landing zone
proceed_to_symbol(SymbolType::LeadIn);
proceed_to_landing_zone(is_original);
reset_parity_byte();
// accumulate until the next non-word marker is hit
while(!is_at_end())
{
SymbolType start_symbol = get_next_symbol();
if(start_symbol != SymbolType::Word) break;
data->data.push_back(get_next_byte_contents());
}
// the above has reead the parity byte to the end of the data; if it matched the calculated parity it'll now be zero
data->parity_was_valid = !get_parity_byte();
data->duplicate_matched = false;
// remove the captured parity
data->data.erase(data->data.end()-1);
if(get_error_flag()) return nullptr;
return data;
}
/*!
Finds and completes the next landing zone.
*/
void proceed_to_landing_zone(bool is_original)
{
uint8_t landing_zone[9] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
while(!is_at_end())
{
memmove(landing_zone, &landing_zone[1], sizeof(uint8_t) * 8);
landing_zone[8] = get_next_byte();
bool is_landing_zone = true;
for(int c = 0; c < 9; c++)
{
if(landing_zone[c] != ((is_original ? 0x80 : 0x00) | 0x9) - c)
{
is_landing_zone = false;
break;
}
}
if(is_landing_zone) break;
}
}
/*!
Swallows symbols until it reaches the first instance of the required symbol, swallows that
and returns.
*/
void proceed_to_symbol(SymbolType required_symbol)
{
while(!is_at_end())
{
SymbolType symbol = get_next_symbol();
if(symbol == required_symbol) return;
}
}
/*!
Swallows the next byte; sets the error flag if it is not equal to @c value.
*/
void expect_byte(uint8_t value)
{
uint8_t next_byte = get_next_byte();
if(next_byte != value) set_error_flag();
}
uint8_t _parity_byte;
void reset_parity_byte() { _parity_byte = 0; }
uint8_t get_parity_byte() { return _parity_byte; }
void add_parity_byte(uint8_t byte) { _parity_byte ^= byte; }
/*!
Proceeds to the next word marker then returns the result of @c get_next_byte_contents.
*/
uint8_t get_next_byte()
{
proceed_to_symbol(SymbolType::Word);
return get_next_byte_contents();
}
/*!
Reads the next nine symbols and applies a binary test to each to differentiate between ::One and not-::One.
Returns a byte composed of the first eight of those as bits; sets the error flag if any symbol is not
::One and not ::Zero, or if the ninth bit is not equal to the odd parity of the other eight.
*/
uint8_t get_next_byte_contents()
{
int byte_plus_parity = 0;
int c = 9;
while(c--)
{
SymbolType next_symbol = get_next_symbol();
if((next_symbol != SymbolType::One) && (next_symbol != SymbolType::Zero)) set_error_flag();
byte_plus_parity = (byte_plus_parity >> 1) | (((next_symbol == SymbolType::One) ? 1 : 0) << 8);
}
int check = byte_plus_parity;
check ^= (check >> 4);
check ^= (check >> 2);
check ^= (check >> 1);
if((check&1) == (byte_plus_parity >> 8))
set_error_flag();
add_parity_byte((uint8_t)byte_plus_parity);
return (uint8_t)byte_plus_parity;
}
/*!
Returns the result of two consecutive @c get_next_byte calls, arranged in little-endian format.
*/
uint16_t get_next_short()
{
uint16_t value = get_next_byte();
value |= get_next_byte() << 8;
return value;
}
/*!
Per the contract with StaticAnalyser::TapeParser; sums time across pulses. If this pulse
indicates a high to low transition, inspects the time since the last transition, to produce
a long, medium, short or unrecognised wave period.
*/
void process_pulse(Storage::Tape::Tape::Pulse pulse)
{
// The Complete Commodore Inner Space Anthology, P 97, gives half-cycle lengths of:
// short: 182µs => 0.000364s cycle
// medium: 262µs => 0.000524s cycle
// long: 342µs => 0.000684s cycle
bool is_high = pulse.type == Storage::Tape::Tape::Pulse::High;
if(!is_high && _previous_was_high)
{
if(_wave_period >= 0.000764) push_wave(WaveType::Unrecognised);
else if(_wave_period >= 0.000604) push_wave(WaveType::Long);
else if(_wave_period >= 0.000444) push_wave(WaveType::Medium);
else if(_wave_period >= 0.000284) push_wave(WaveType::Short);
else push_wave(WaveType::Unrecognised);
_wave_period = 0.0f;
}
_wave_period += pulse.length.get_float();
_previous_was_high = is_high;
}
bool _previous_was_high;
float _wave_period;
/*!
Per the contract with StaticAnalyser::TapeParser; produces any of a word marker, an end-of-block marker,
a zero, a one or a lead-in symbol based on the currently captured waves.
*/
void inspect_waves(const std::vector<WaveType> &waves)
{
if(waves.size() < 2) return;
if(waves[0] == WaveType::Long && waves[1] == WaveType::Medium)
{
push_symbol(SymbolType::Word, 2);
return;
}
if(waves[0] == WaveType::Long && waves[1] == WaveType::Short)
{
push_symbol(SymbolType::EndOfBlock, 2);
return;
}
if(waves[0] == WaveType::Short && waves[1] == WaveType::Medium)
{
push_symbol(SymbolType::Zero, 2);
return;
}
if(waves[0] == WaveType::Medium && waves[1] == WaveType::Short)
{
push_symbol(SymbolType::One, 2);
return;
}
if(waves[0] == WaveType::Short)
{
push_symbol(SymbolType::LeadIn, 1);
return;
}
// Otherwise, eject at least one wave as all options are exhausted.
remove_waves(1);
}
};
std::list<File> StaticAnalyser::Commodore::GetFiles(const std::shared_ptr<Storage::Tape::Tape> &tape)
{
CommodoreROMTapeParser parser(tape);
std::list<File> file_list;
std::unique_ptr<Header> header = parser.get_next_header();
while(!parser.is_at_end())
{
if(!header)
{
header = parser.get_next_header();
continue;
}
switch(header->type)
{
case Header::DataSequenceHeader:
{
File new_file;
new_file.name = header->name;
new_file.raw_name = header->raw_name;
new_file.starting_address = header->starting_address;
new_file.ending_address = header->ending_address;
new_file.type = File::DataSequence;
new_file.data.swap(header->data);
while(!parser.is_at_end())
{
header = parser.get_next_header();
if(!header) continue;
if(header->type != Header::DataBlock) break;
std::copy(header->data.begin(), header->data.end(), std::back_inserter(new_file.data));
}
file_list.push_back(new_file);
}
break;
case Header::RelocatableProgram:
case Header::NonRelocatableProgram:
{
std::unique_ptr<Data> data = parser.get_next_data();
if(data)
{
File new_file;
new_file.name = header->name;
new_file.raw_name = header->raw_name;
new_file.starting_address = header->starting_address;
new_file.ending_address = header->ending_address;
new_file.data.swap(data->data);
new_file.type = (header->type == Header::RelocatableProgram) ? File::RelocatableProgram : File::NonRelocatableProgram;
file_list.push_back(new_file);
}
header = parser.get_next_header();
}
break;
default:
header = parser.get_next_header();
break;
}
}
return file_list;
}