From add32572585c8654d257c75ce6f8b1127bcfdb30 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Mon, 11 Dec 2023 19:13:37 -0500
Subject: [PATCH] Switch to using a `Parser` rather than duplicating one.
---
Machines/PCCompatible/PCCompatible.cpp | 141 +++++--------------------
1 file changed, 28 insertions(+), 113 deletions(-)
diff --git a/Machines/PCCompatible/PCCompatible.cpp b/Machines/PCCompatible/PCCompatible.cpp
index 382b5b277..57504d156 100644
--- a/Machines/PCCompatible/PCCompatible.cpp
+++ b/Machines/PCCompatible/PCCompatible.cpp
@@ -34,8 +34,7 @@
#include "../../Outputs/Speaker/Implementation/LowpassSpeaker.hpp"
#include "../../Storage/Disk/Track/TrackSerialiser.hpp"
-#include "../../Storage/Disk/Encodings/MFM/Constants.hpp"
-#include "../../Storage/Disk/Encodings/MFM/SegmentParser.hpp"
+#include "../../Storage/Disk/Encodings/MFM/Parser.hpp"
#include "../AudioProducer.hpp"
#include "../KeyboardMachine.hpp"
@@ -150,50 +149,36 @@ class FloppyController {
auto target = decoder_.geometry();
bool complete = false;
while(!complete) {
- bool found_sector = false;
+ const auto sector = drives_[decoder_.target().drive].sector(target.head, target.sector);
- for(auto &pair: drives_[decoder_.target().drive].sectors(decoder_.target().head)) {
- // TODO: I suspect that not all these fields are tested for equality.
- if(
- (pair.second.address.track == target.cylinder) &&
- (pair.second.address.sector == target.sector) &&
- (pair.second.address.side == target.head) &&
- (pair.second.size == target.size) &&
- (pair.second.is_deleted == (decoder_.command() == Command::ReadDeletedData))
- ) {
- found_sector = true;
- bool wrote_in_full = true;
+ if(sector) {
+ bool wrote_in_full = true;
- for(int c = 0; c < 128 << target.size; c++) {
- const auto access_result = dma_.write(2, pair.second.samples[0].data()[c]);
- switch(access_result) {
- default: break;
- case AccessResult::NotAccepted:
- complete = true;
- wrote_in_full = false;
- break;
- case AccessResult::AcceptedWithEOP:
- complete = true;
- break;
- }
- if(access_result != AccessResult::Accepted) {
- break;
- }
- }
-
- if(!wrote_in_full) {
- status_.set(Intel::i8272::Status1::OverRun);
- status_.set(Intel::i8272::Status0::AbnormalTermination);
+ for(int c = 0; c < 128 << target.size; c++) {
+ const auto access_result = dma_.write(2, sector->samples[0].data()[c]);
+ switch(access_result) {
+ default: break;
+ case AccessResult::NotAccepted:
+ complete = true;
+ wrote_in_full = false;
+ break;
+ case AccessResult::AcceptedWithEOP:
+ complete = true;
break;
}
+ if(access_result != AccessResult::Accepted) {
+ break;
+ }
+ }
- ++target.sector; // TODO: multitrack?
-
+ if(!wrote_in_full) {
+ status_.set(Intel::i8272::Status1::OverRun);
+ status_.set(Intel::i8272::Status0::AbnormalTermination);
break;
}
- }
- if(!found_sector) {
+ ++target.sector; // TODO: multitrack?
+ } else {
status_.set(Intel::i8272::Status1::EndOfCylinder);
status_.set(Intel::i8272::Status0::AbnormalTermination);
break;
@@ -342,89 +327,19 @@ class FloppyController {
bool exists = true;
bool has_disk() const {
- return bool(disk);
+ return static_cast<bool>(parser_);
}
void set_disk(std::shared_ptr<Storage::Disk::Disk> image) {
- disk = image;
- cached.clear();
+ parser_ = std::make_unique<Storage::Encodings::MFM::Parser>(image);
}
- Storage::Encodings::MFM::SectorMap §ors(bool side) {
- if(cached.track == track && cached.side == side) {
- return cached.sectors;
- }
-
- cached.track = track;
- cached.side = side;
- cached.sectors.clear();
-
- if(!disk) {
- return cached.sectors;
- }
-
- auto raw_track = disk->get_track_at_position(
- Storage::Disk::Track::Address(
- side,
- Storage::Disk::HeadPosition(track)
- )
- );
- if(!raw_track) {
- return cached.sectors;
- }
-
- const bool is_mfm = true; // TODO: use MFM flag here.
-
- Storage::Disk::PCMSegment serialisation;
-
- // If attempting to load as FM then use the FM bit length only;
- // if MFM decoding is enabled then try both double- and high-density
- // parsings, keeping whichever provides the most meaningful reading.
- //
- // TODO: there must be a hardware selection for this somewhere on real hardware.
- // Though not necessarily on an XT.
- if(!is_mfm) {
- serialisation = Storage::Disk::track_serialisation(
- *raw_track,
- Storage::Encodings::MFM::FMBitLength
- );
- cached.sectors = Storage::Encodings::MFM::sectors_from_segment(std::move(serialisation), Storage::Encodings::MFM::Density::Single);
- return cached.sectors;
- }
-
- // Get double-density candidate.
- serialisation = Storage::Disk::track_serialisation(
- *raw_track,
- Storage::Encodings::MFM::MFMBitLength
- );
- auto double_candidate = Storage::Encodings::MFM::sectors_from_segment(std::move(serialisation), Storage::Encodings::MFM::Density::High);
-
- // Get high-density candidate.
- serialisation = Storage::Disk::track_serialisation(
- *raw_track,
- Storage::Encodings::MFM::HDMFMBitLength
- );
- auto high_candidate = Storage::Encodings::MFM::sectors_from_segment(std::move(serialisation), Storage::Encodings::MFM::Density::Double);
-
- // Pick the more populous.
- cached.sectors = high_candidate.size() > double_candidate.size() ?
- std::move(high_candidate) : std::move(double_candidate);
-
- return cached.sectors;
+ const Storage::Encodings::MFM::Sector *sector(int head, uint8_t sector) {
+ return parser_ ? parser_->sector(head, track, sector) : nullptr;
}
private:
- struct {
- uint8_t track = 0xff;
- bool side;
- Storage::Encodings::MFM::SectorMap sectors;
-
- void clear() {
- track = 0xff;
- sectors.clear();
- }
- } cached;
- std::shared_ptr<Storage::Disk::Disk> disk;
+ std::unique_ptr<Storage::Encodings::MFM::Parser> parser_;
} drives_[4];