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This likely gets chunks 0100 and 0102 correct.

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This commit is contained in:
Thomas Harte 2016-01-18 19:37:36 -06:00
parent 5a39e42413
commit 7d6214e078
2 changed files with 85 additions and 3 deletions
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81
Storage/Tape/Formats/TapeUEF.cpp
View File

@ -48,12 +48,40 @@ Storage::Tape::Pulse Storage::UEF::get_next_pulse()
{
Pulse next_pulse;
if(!_bit_position && chunk_is_finished())
{
find_next_tape_chunk();
}
next_pulse.length.clock_rate = _time_base;
switch(_chunk_id)
{
case 0x0100: case 0x0102: case 0x0110: case 0x0111: case 0x0114:
{
// 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;
_bit_position = (_bit_position+1)&(_current_bit ? 3 : 1);
} break;
}
return next_pulse;
}
void Storage::UEF::find_next_tape_chunk()
{
int reset_count = 0;
_chunk_position = 0;
_bit_position = 0;
while(1)
{
@ -66,9 +94,7 @@ void Storage::UEF::find_next_tape_chunk()
_chunk_length |= (uint32_t)(gzgetc(_file) << 16);
_chunk_length |= (uint32_t)(gzgetc(_file) << 24);
printf("%04x: %d\n", _chunk_id, _chunk_length);
if (gzeof(_file))
if(gzeof(_file))
{
reset_count++;
if(reset_count == 2) break;
@ -101,3 +127,52 @@ void Storage::UEF::find_next_tape_chunk()
}
}
}
bool Storage::UEF::chunk_is_finished()
{
switch(_chunk_id)
{
case 0x0100: return (_chunk_position / 10) == _chunk_length;
case 0x0102: return (_chunk_position / 8) == _chunk_length;
default: return true;
}
}
bool Storage::UEF::get_next_bit()
{
switch(_chunk_id)
{
case 0x0100:
{
uint32_t bit_position = _chunk_position%10;
_chunk_position++;
if(!bit_position)
{
_current_byte = (uint8_t)gzgetc(_file);
}
if(bit_position == 0) return false;
if(bit_position == 9) return true;
bool result = (_current_byte&1) ? true : false;
_current_byte >>= 1;
return result;
}
break;
case 0x0102:
{
uint32_t bit_position = _chunk_position%8;
_chunk_position++;
if(!bit_position)
{
_current_byte = (uint8_t)gzgetc(_file);
}
bool result = (_current_byte&1) ? true : false;
_current_byte >>= 1;
return result;
}
break;
default: return true;
}
}

7
Storage/Tape/Formats/TapeUEF.hpp
View File

@ -29,9 +29,16 @@ class UEF : public Tape {
uint16_t _chunk_id;
uint32_t _chunk_length;
uint8_t _current_byte;
uint32_t _chunk_position;
bool _current_bit;
uint32_t _bit_position;
void find_next_tape_chunk();
bool get_next_bit();
bool chunk_is_finished();
};
}