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999a0c22d4
In the sense that the file format itself is properly parsed, but the MSX doesn't actually yet have disk hardware.
60 lines
1.5 KiB
C++
60 lines
1.5 KiB
C++
//
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// MSXDSK.cpp
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// Clock Signal
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//
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// Created by Thomas Harte on 07/01/2018.
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// Copyright © 2018 Thomas Harte. All rights reserved.
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//
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#include "MSXDSK.hpp"
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#include "Utility/ImplicitSectors.hpp"
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namespace {
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static const int sectors_per_track = 9;
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static const int sector_size = 2;
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}
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using namespace Storage::Disk;
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MSXDSK::MSXDSK(const char *file_name) :
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MFMSectorDump(file_name) {
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// The only sanity check here is whether a sensible
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// geometry can be guessed.
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off_t file_size = file_.stats().st_size;
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const off_t track_size = 512*9;
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// Throw if there would seemingly be an incomplete track.
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if(file_size % track_size) throw ErrorNotMSXDSK;
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track_count_ = static_cast<int>(file_size / track_size);
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head_count_ = 1;
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// Throw if too large or too small or too large for single sided and
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// clearly not double sided.
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if(track_count_ < 40) throw ErrorNotMSXDSK;
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if(track_count_ > 82*2) throw ErrorNotMSXDSK;
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if(track_count_ > 82 && track_count_&1) throw ErrorNotMSXDSK;
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// The below effectively prefers the idea of a single-sided 80-track disk
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// to a double-sided 40-track disk. Emulators have to guess.
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if(track_count_ > 82) {
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track_count_ /= 2;
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head_count_ = 2;
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}
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set_geometry(sectors_per_track, sector_size, true);
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}
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int MSXDSK::get_head_position_count() {
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return track_count_;
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}
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int MSXDSK::get_head_count() {
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return head_count_;
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}
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long MSXDSK::get_file_offset_for_position(Track::Address address) {
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return (address.position + address.head*track_count_) * 512 * 9;
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}
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