6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2025-01-14 13:33:42 +00:00
Code Issues Projects Releases Wiki Activity

Ensures initialisation of scanner and that sectors overlapping the end of track are captured.

Browse Source
This commit is contained in:
Thomas Harte 2018-05-12 18:42:07 -04:00
parent f410dcb3f3
commit 49592ebaf3
1 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
Storage/Disk/Encodings/AppleGCR/SegmentParser.cpp
View File

@ -45,11 +45,15 @@ std::map<std::size_t, Sector> Storage::Encodings::AppleGCR::sectors_from_segment
std::size_t sector_location = 0; std::size_t sector_location = 0;
std::size_t pointer = scanning_sentinel; std::size_t pointer = scanning_sentinel;
std::array<uint_fast8_t, 8> header{{0, 0, 0, 0, 0, 0, 0, 0}}; std::array<uint_fast8_t, 8> header{{0, 0, 0, 0, 0, 0, 0, 0}};
std::array<uint_fast8_t, 3> scanner; std::array<uint_fast8_t, 3> scanner{{0, 0, 0}};
// Scan the track 1 and 1/8th times; that's long enough to make sure that any sector which straddles the
// end of the track is caught. Since they're put into a map, it doesn't matter if they're caught twice.
unsigned int extended_length = segment.number_of_bits + (segment.number_of_bits >> 3);
for(unsigned int bit = 0; bit < extended_length; ++bit) {
shift_register = static_cast<uint_fast8_t>((shift_register << 1) | segment.bit(bit % segment.number_of_bits));
for(unsigned int bit = 0; bit < segment.number_of_bits; ++bit) {
// Apple GCR parsing: bytes always have the top bit set. // Apple GCR parsing: bytes always have the top bit set.
shift_register = static_cast<uint_fast8_t>((shift_register << 1) | segment.bit(bit));
if(!(shift_register&0x80)) continue; if(!(shift_register&0x80)) continue;
// Grab the byte. // Grab the byte.
@ -76,7 +80,7 @@ std::map<std::size_t, Sector> Storage::Encodings::AppleGCR::sectors_from_segment
new_sector.reset(new Sector); new_sector.reset(new Sector);
new_sector->data.reserve(412); new_sector->data.reserve(412);
} else { } else {
sector_location = static_cast<std::size_t>(bit); sector_location = static_cast<std::size_t>(bit % segment.number_of_bits);
} }
} }
} else { } else {