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I've obviously misunderstood something as, as far as I'm concerned, this should at least get me a 'LOADING'.

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This commit is contained in:
Thomas Harte 2016-08-15 22:40:05 -04:00
parent 7994148f55
commit dbe47f3f45
2 changed files with 52 additions and 7 deletions
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56
Storage/Tape/Formats/TapePRG.cpp
View File

@ -27,8 +27,9 @@ TapePRG::TapePRG(const char *file_name) : _file(nullptr), _bitPhase(3), _filePha
_load_address = (uint16_t)fgetc(_file);
_load_address |= (uint16_t)fgetc(_file) << 8;
_length = (uint16_t)(file_stats.st_size - 2);
if (_load_address + file_stats.st_size >= 65536)
if (_load_address + _length >= 65536)
throw ErrorBadFormat;
}
@ -42,7 +43,7 @@ Tape::Pulse TapePRG::get_next_pulse()
static const unsigned int leader_zero_length = 179;
static const unsigned int zero_length = 169;
static const unsigned int one_length = 247;
static const unsigned int word_marker_length = 328;
static const unsigned int marker_length = 328;
_bitPhase = (_bitPhase+1)&3;
if(!_bitPhase) get_next_output_token();
@ -50,10 +51,11 @@ Tape::Pulse TapePRG::get_next_pulse()
Tape::Pulse pulse;
switch(_outputToken)
{
case Leader: pulse.length.length = leader_zero_length; break;
case Zero: pulse.length.length = (_bitPhase&2) ? one_length : zero_length; break;
case One: pulse.length.length = (_bitPhase&2) ? zero_length : one_length; break;
case WordMarker: pulse.length.length = (_bitPhase&2) ? one_length : word_marker_length; break;
case Leader: pulse.length.length = leader_zero_length; break;
case Zero: pulse.length.length = (_bitPhase&2) ? one_length : zero_length; break;
case One: pulse.length.length = (_bitPhase&2) ? zero_length : one_length; break;
case WordMarker: pulse.length.length = (_bitPhase&2) ? one_length : marker_length; break;
case EndOfBlock: pulse.length.length = (_bitPhase&2) ? zero_length : marker_length; break;
}
pulse.length.clock_rate = 1000000;
pulse.type = (_bitPhase&1) ? Pulse::Low : Pulse::High;
@ -89,16 +91,56 @@ void TapePRG::get_next_output_token()
int bit_offset = block_offset % 10;
int byte_offset = block_offset / 10;
if(byte_offset == 200)
{
_phaseOffset = 0;
_filePhase = FilePhaseData; // TODO
_outputToken = EndOfBlock;
return;
}
_phaseOffset++;
if(bit_offset == 0)
{
// the first nine bytes are countdown; the high bit is set if this is a header
if(byte_offset < 9)
{
_output_byte = (uint8_t)(9 - block_offset) | 0x80;
_output_byte = (uint8_t)(9 - byte_offset) | 0x80;
_check_digit = 0;
}
else if(byte_offset == 199)
{
_output_byte = _check_digit;
}
else
{
if(_filePhase == FilePhaseHeader)
{
switch(byte_offset - 9)
{
case 0: _output_byte = 0x03; break;
case 1: _output_byte = _load_address & 0xff; break;
case 2: _output_byte = (_load_address >> 8)&0xff; break;
case 3: _output_byte = (_load_address + _length) & 0xff; break;
case 4: _output_byte = ((_load_address + _length) >> 8) & 0xff; break;
case 5: _output_byte = 0x50; break; // P
case 6: _output_byte = 0x72; break; // R
case 7: _output_byte = 0x67; break; // G
default:
_output_byte = 0x20;
break;
}
}
else
{
_output_byte = (uint8_t)fgetc(_file);
if(feof(_file)) _output_byte = 0x20;
}
}
printf("%02x ", _output_byte);
_check_digit ^= _output_byte;
}
switch(bit_offset)

3
Storage/Tape/Formats/TapePRG.hpp
View File

@ -39,6 +39,7 @@ class TapePRG: public Tape {
private:
FILE *_file;
uint16_t _load_address;
uint16_t _length;
enum FilePhase {
FilePhaseLeadIn,
@ -53,9 +54,11 @@ class TapePRG: public Tape {
Zero,
One,
WordMarker,
EndOfBlock
} _outputToken;
void get_next_output_token();
uint8_t _output_byte;
uint8_t _check_digit;
};
}