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CLK/Storage/Disk/DiskImage/Formats/ST.cpp
2019-12-22 00:22:17 -05:00

43 lines
1.1 KiB
C++

//
// ST.cpp
// Clock Signal
//
// Created by Thomas Harte on 12/11/2019.
// Copyright © 2019 Thomas Harte. All rights reserved.
//
#include "ST.hpp"
namespace {
constexpr int sectors_per_track = 10;
constexpr int sector_size = 2;
}
using namespace Storage::Disk;
ST::ST(const std::string &file_name) : MFMSectorDump(file_name) {
// Very loose validation: the file needs to be a whole number of tracks,
// and not more than 160 of them.
const auto stats = file_.stats();
if(stats.st_size % (512*10)) throw Error::InvalidFormat;
if(stats.st_size > 512*10*160) throw Error::InvalidFormat;
// Head count: 2 if there are more than 80 tracks. Otherwise 1.
head_count_ = (stats.st_size >= 512 * 10 * 80) ? 2 : 1;
track_count_ = std::max(80, int(stats.st_size / (512 * 10 * head_count_)));
set_geometry(sectors_per_track, sector_size, 1, true);
}
HeadPosition ST::get_maximum_head_position() {
return HeadPosition(track_count_);
}
int ST::get_head_count() {
return head_count_;
}
long ST::get_file_offset_for_position(Track::Address address) {
return (address.position.as_int() * head_count_ + address.head) * 512 * sectors_per_track;
}