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I am instructed that the Oric actually catches only positive transitions, and compares the distance between those to a threshold. So here's an altered version of the tape parser that does that.

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This commit is contained in:
Thomas Harte 2016-11-09 06:37:10 -05:00
parent 79dd062941
commit fce48b9b8c
2 changed files with 45 additions and 47 deletions
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87
Storage/Tape/Parsers/Oric.cpp
View File

@ -47,14 +47,17 @@ bool Parser::sync_and_get_encoding_speed(const std::shared_ptr<Storage::Tape::Ta
void Parser::process_pulse(Storage::Tape::Tape::Pulse pulse)
{
const float length_threshold = 0.0003125f;
const float maximum_short_length = 0.000512f;
const float maximum_medium_length = 0.000728f;
const float maximum_long_length = 0.001456f;
bool wave_is_high = pulse.type == Storage::Tape::Tape::Pulse::High;
if(wave_is_high != _wave_was_high && _cycle_length > 0.0f)
if(!_wave_was_high && wave_is_high != _wave_was_high)
{
if(_cycle_length > 2.0 * length_threshold)
push_wave(WaveType::Unrecognised);
else push_wave(_cycle_length < length_threshold ? WaveType::Short : WaveType::Long);
if(_cycle_length < maximum_short_length) push_wave(WaveType::Short);
else if(_cycle_length < maximum_medium_length) push_wave(WaveType::Medium);
else if(_cycle_length < maximum_long_length) push_wave(WaveType::Long);
else push_wave(WaveType::Unrecognised);
_cycle_length = 0.0f;
}
@ -67,31 +70,33 @@ void Parser::inspect_waves(const std::vector<WaveType> &waves)
switch(_detection_mode)
{
case FastZero:
if(waves.size() < 2) return;
if(waves[0] == WaveType::Short && waves[1] == WaveType::Long)
if(waves.empty()) return;
if(waves[0] == WaveType::Medium)
{
push_symbol(SymbolType::Zero, 2);
push_symbol(SymbolType::Zero, 1);
return;
}
break;
case FastData:
if(waves.size() < 2) return;
if(waves[0] == WaveType::Short && waves[1] != WaveType::Unrecognised)
if(waves.empty()) return;
if(waves[0] == WaveType::Medium)
{
push_symbol((waves[1] == WaveType::Long) ? SymbolType::Zero : SymbolType::One, 2);
push_symbol(SymbolType::Zero, 1);
return;
}
if(waves[0] == WaveType::Short)
{
push_symbol(SymbolType::One, 1);
return;
}
break;
case SlowZero:
if(waves.size() < 8) return;
if(
waves[0] == WaveType::Long && waves[1] == WaveType::Long && waves[2] == WaveType::Long && waves[3] == WaveType::Long &&
waves[4] == WaveType::Long && waves[5] == WaveType::Long && waves[6] == WaveType::Long && waves[7] == WaveType::Long
)
if(waves.size() < 4) return;
if(waves[0] == WaveType::Long && waves[1] == WaveType::Long && waves[2] == WaveType::Long && waves[3] == WaveType::Long)
{
push_symbol(SymbolType::Zero, 8);
push_symbol(SymbolType::Zero, 4);
return;
}
break;
@ -104,13 +109,13 @@ void Parser::inspect_waves(const std::vector<WaveType> &waves)
for(c = 0; c < length; c++) if(waves[c] != type) break;\
if(c == length)\
{\
push_symbol(symbol, 8);\
push_symbol(symbol, length);\
return;\
}\
}
CHECK_RUN(8, WaveType::Long, SymbolType::Zero);
CHECK_RUN(16, WaveType::Short, SymbolType::One);
CHECK_RUN(4, WaveType::Long, SymbolType::Zero);
CHECK_RUN(8, WaveType::Short, SymbolType::One);
#undef CHECK_RUN
if(waves.size() < 16) return; // TODO, maybe: if there are any inconsistencies in the first 8, don't return
break;
@ -118,48 +123,38 @@ void Parser::inspect_waves(const std::vector<WaveType> &waves)
case Sync:
{
// Sync is 0x16, either encoded fast or slow; i.e. 0 0110 1000 1
// So, fast: [short, long]*2, [short, short]*2, [short, long], [short, short], [short, long]*3, [short, short] = 20
// [short, short] = 1; [short, long] = 0
// Slow: long*16, short*32, long*8, short*16, long*24, short*16 = 112
Pattern slow_sync[] =
{
{.type = WaveType::Long, 16},
{.type = WaveType::Short, 32},
{.type = WaveType::Long, 8},
{.type = WaveType::Short, 16},
{.type = WaveType::Long, 24},
{.type = WaveType::Short, 16},
{.type = WaveType::Long, 8},
{.type = WaveType::Short, 16},
{.type = WaveType::Long, 4},
{.type = WaveType::Short, 8},
{.type = WaveType::Long, 12},
{.type = WaveType::Short, 8},
{.type = WaveType::Unrecognised}
};
Pattern fast_sync[] =
{
{.type = WaveType::Short, 1},
{.type = WaveType::Long, 1},
{.type = WaveType::Short, 1},
{.type = WaveType::Long, 1},
{.type = WaveType::Short, 5},
{.type = WaveType::Long, 1},
{.type = WaveType::Short, 3},
{.type = WaveType::Long, 1},
{.type = WaveType::Short, 1},
{.type = WaveType::Long, 1},
{.type = WaveType::Short, 1},
{.type = WaveType::Long, 1},
{.type = WaveType::Short, 2},
{.type = WaveType::Medium, 2},
{.type = WaveType::Short, 2},
{.type = WaveType::Medium, 1},
{.type = WaveType::Short, 1},
{.type = WaveType::Medium, 3},
{.type = WaveType::Short, 1},
{.type = WaveType::Unrecognised}
};
size_t slow_sync_matching_depth = pattern_matching_depth(waves, slow_sync);
size_t fast_sync_matching_depth = pattern_matching_depth(waves, fast_sync);
if(slow_sync_matching_depth == 112)
if(slow_sync_matching_depth == 52)
{
push_symbol(SymbolType::FoundSlow, 112);
push_symbol(SymbolType::FoundSlow, 52);
return;
}
if(fast_sync_matching_depth == 20)
if(fast_sync_matching_depth == 10)
{
push_symbol(SymbolType::FoundFast, 20);
push_symbol(SymbolType::FoundFast, 10);
return;
}
if(slow_sync_matching_depth < waves.size() && fast_sync_matching_depth < waves.size())

5
Storage/Tape/Parsers/Oric.hpp
View File

@ -16,7 +16,10 @@ namespace Tape {
namespace Oric {
enum class WaveType {
Short, Long, Unrecognised
Short, // i.e. 416µs
Medium, // i.e. 624µs
Long, // i.e. 832µs
Unrecognised
};
enum class SymbolType {