From d065d6d98fb8e17f9b9a694f92a6973ee9a635cb Mon Sep 17 00:00:00 2001 From: Thomas Harte Date: Wed, 15 Jul 2020 19:15:03 -0400 Subject: [PATCH] Adds read-only WOZ 2 support. --- Storage/Disk/DiskImage/Formats/WOZ.cpp | 71 ++++++++++++++++++++------ Storage/Disk/DiskImage/Formats/WOZ.hpp | 3 ++ 2 files changed, 58 insertions(+), 16 deletions(-) diff --git a/Storage/Disk/DiskImage/Formats/WOZ.cpp b/Storage/Disk/DiskImage/Formats/WOZ.cpp index 78c50f1f2..bea9fd702 100644 --- a/Storage/Disk/DiskImage/Formats/WOZ.cpp +++ b/Storage/Disk/DiskImage/Formats/WOZ.cpp @@ -18,11 +18,21 @@ using namespace Storage::Disk; WOZ::WOZ(const std::string &file_name) : file_(file_name) { - const char signature[8] = { + constexpr const char signature1[8] = { 'W', 'O', 'Z', '1', char(0xff), 0x0a, 0x0d, 0x0a }; - if(!file_.check_signature(signature, 8)) throw Error::InvalidFormat; + constexpr const char signature2[8] = { + 'W', 'O', 'Z', '2', + char(0xff), 0x0a, 0x0d, 0x0a + }; + + const bool isWoz1 = file_.check_signature(signature1, 8); + file_.seek(0, SEEK_SET); + const bool isWoz2 = file_.check_signature(signature2, 8); + + if(!isWoz1 && !isWoz2) throw Error::InvalidFormat; + type_ = isWoz2 ? Type::WOZ2 : Type::WOZ1; // Get the file's CRC32. const uint32_t crc = file_.get32le(); @@ -52,13 +62,22 @@ WOZ::WOZ(const std::string &file_name) : switch(chunk_id) { case CK("INFO"): { const uint8_t version = file_.get8(); - if(version != 1) break; + if(version > 2) break; is_3_5_disk_ = file_.get8() == 2; is_read_only_ = file_.get8() == 1; - /* Ignored: - 1 byte: Synchronized; 1 = Cross track sync was used during imaging. - 1 byte: Cleaned; 1 = MC3470 fake bits have been removed. - 32 bytes: Cretor; a UTF-8 string. + /* + Ignored: + 1 byte: Synchronized; 1 = Cross track sync was used during imaging. + 1 byte: Cleaned; 1 = MC3470 fake bits have been removed. + 32 bytes: Creator; a UTF-8 string. + + And, if version 2, following the creator: + 1 byte number of disk sides + 1 byte boot sector format + 1 byte optimal bit timing + 2 bytes compatible hardware + 2 bytes minimum required RAM + 2 bytes largest track */ } break; @@ -99,11 +118,15 @@ long WOZ::file_offset(Track::Address address) { if(track_map_[table_position] == 0xff) return NoSuchTrack; // Seek to the real track. - return tracks_offset_ + track_map_[table_position] * 6656; + switch(type_) { + case Type::WOZ1: return tracks_offset_ + track_map_[table_position] * 6656; + default: + case Type::WOZ2: return tracks_offset_ + track_map_[table_position] * 8; + } } std::shared_ptr WOZ::get_track_at_position(Track::Address address) { - long offset = file_offset(address); + const long offset = file_offset(address); if(offset == NoSuchTrack) return nullptr; // Seek to the real track. @@ -113,18 +136,34 @@ std::shared_ptr WOZ::get_track_at_position(Track::Address address) { std::lock_guard lock_guard(file_.get_file_access_mutex()); file_.seek(offset, SEEK_SET); - // In WOZ a track is up to 6646 bytes of data, followed by a two-byte record of the - // number of bytes that actually had data in them, then a two-byte count of the number - // of bits that were used. Other information follows but is not intended for emulation. - track_contents = file_.read(6646); - file_.seek(2, SEEK_CUR); - number_of_bits = std::min(file_.get16le(), uint16_t(6646*8)); + switch(type_) { + case Type::WOZ1: + // In WOZ 1, a track is up to 6646 bytes of data, followed by a two-byte record of the + // number of bytes that actually had data in them, then a two-byte count of the number + // of bits that were used. Other information follows but is not intended for emulation. + track_contents = file_.read(6646); + file_.seek(2, SEEK_CUR); + number_of_bits = std::min(file_.get16le(), uint16_t(6646*8)); + break; + + case Type::WOZ2: { + // In WOZ 2 an extra level of indirection allows for variable track sizes. + const uint16_t starting_block = file_.get16le(); + file_.seek(2, SEEK_CUR); // Skip the block count; the amount of data to read is implied by the number of bits. + number_of_bits = file_.get32le(); + + file_.seek(starting_block * 512, SEEK_SET); + track_contents = file_.read((number_of_bits + 7) >> 3); + } break; + } } return std::make_shared(PCMSegment(number_of_bits, track_contents)); } void WOZ::set_tracks(const std::map> &tracks) { + if(type_ == Type::WOZ2) return; + for(const auto &pair: tracks) { // Decode the track and store, patching into the post_crc_contents_. auto segment = Storage::Disk::track_serialisation(*pair.second, Storage::Time(1, 50000)); @@ -155,5 +194,5 @@ void WOZ::set_tracks(const std::map> &tra } bool WOZ::get_is_read_only() { - return file_.get_is_known_read_only(); + return file_.get_is_known_read_only() || is_read_only_ || type_ == Type::WOZ2; // WOZ 2 disks are currently read only. } diff --git a/Storage/Disk/DiskImage/Formats/WOZ.hpp b/Storage/Disk/DiskImage/Formats/WOZ.hpp index de1821d9b..c0531a94c 100644 --- a/Storage/Disk/DiskImage/Formats/WOZ.hpp +++ b/Storage/Disk/DiskImage/Formats/WOZ.hpp @@ -34,6 +34,9 @@ class WOZ: public DiskImage { private: Storage::FileHolder file_; + enum class Type { + WOZ1, WOZ2 + } type_ = Type::WOZ1; bool is_read_only_ = false; bool is_3_5_disk_ = false; uint8_t track_map_[160];