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Merge pull request #369 from tdaede/d88plus

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Use per-track encoding specified in D88 files.
This commit is contained in:
David Given
2021-12-04 11:44:28 +00:00
committed by GitHub
parent f5d04d989c 04b91377c9
commit 8efd95346a
2 changed files with 52 additions and 14 deletions
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4
doc/using.md
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@@ -276,8 +276,8 @@ FluxEngine also supports a number of file system image formats. When using the
FluxEngine is currently limited to reading only the first floppy image in a
D88 file.
In addition, it only supports a limited subset of D88 features and will
reject files not in that subset.
The D88 reader should be used with the `ibm` profile and will override
most encoding parameters on a track-by-track basis.
- `<filename.ldbs>`

62
lib/imagereader/d88imagereader.cc
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@@ -3,6 +3,7 @@
#include "sector.h"
#include "imagereader/imagereader.h"
#include "image.h"
#include "proto.h"
#include "lib/config.pb.h"
#include "imagereader/imagereaderimpl.h"
#include "fmt/format.h"
@@ -59,7 +60,12 @@ public:
ByteReader trackTableReader(trackTable);
int diskSectorsPerTrack = -1;
int diskSectorSize = -1;
if (config.encoder().format_case() != EncoderProto::FormatCase::FORMAT_NOT_SET)
std::cout << "D88: overriding configured format";
auto ibm = config.mutable_encoder()->mutable_ibm();
config.mutable_cylinders()->set_end(0);
std::unique_ptr<Image> image(new Image);
for (int track = 0; track < trackTableSize / 4; track++)
@@ -70,21 +76,32 @@ public:
int currentTrackOffset = trackOffset;
int currentTrackCylinder = -1;
int currentSectorsInTrack = 0xffff; // don't know # of sectors until we read the first one
int trackSectorSize = -1;
int trackMfm = -1;
auto trackdata = ibm->add_trackdata();
trackdata->set_clock_rate_khz(500);
trackdata->set_track_length_ms(167);
auto sectors = trackdata->mutable_sectors();
for (int sectorInTrack = 0; sectorInTrack < currentSectorsInTrack; sectorInTrack++){
Bytes sectorHeader(0x10);
inputFile.read((char*) sectorHeader.begin(), sectorHeader.size());
ByteReader sectorHeaderReader(sectorHeader);
char cylinder = sectorHeaderReader.seek(0).read_8();
char head = sectorHeaderReader.seek(1).read_8();
char sectorId = sectorHeaderReader.seek(2).read_8();
int cylinder = sectorHeaderReader.seek(0).read_8();
int head = sectorHeaderReader.seek(1).read_8();
int sectorId = sectorHeaderReader.seek(2).read_8();
int sectorSize = 128 << sectorHeaderReader.seek(3).read_8();
int sectorsInTrack = sectorHeaderReader.seek(4).read_le16();
int mfm = sectorHeaderReader.seek(6).read_8();
int fm = sectorHeaderReader.seek(6).read_8();
int ddam = sectorHeaderReader.seek(7).read_8();
int fddStatusCode = sectorHeaderReader.seek(8).read_8();
int rpm = sectorHeaderReader.seek(13).read_8();
// D88 provides much more sector information that is currently ignored
if (ddam != 0)
Error() << "D88: nonzero ddam currently unsupported";
if (rpm != 0)
Error() << "D88: 1.44MB 300rpm formats currently unsupported";
if (fddStatusCode != 0)
Error() << "D88: nonzero fdd status codes are currently unsupported";
if (currentSectorsInTrack == 0xffff) {
@@ -97,18 +114,35 @@ public:
} else if (diskSectorsPerTrack != sectorsInTrack) {
Error() << "D88: varying numbers of sectors per track is currently unsupported";
}
if (diskSectorSize < 0) {
diskSectorSize = sectorSize;
} else if (diskSectorSize != sectorSize) {
Error() << "D88: variable sector sizes are currently unsupported";
}
if (mfm != 0)
Error() << "D88: Non-MFM sectors are currenty unsupported";
if (currentTrackCylinder < 0) {
currentTrackCylinder = cylinder;
} else if (currentTrackCylinder != cylinder) {
Error() << "D88: all sectors in a track must belong to the same cylinder";
}
if (trackSectorSize < 0) {
trackSectorSize = sectorSize;
// this is the first sector we've read, use it settings for per-track data
trackdata->set_cylinder(cylinder);
trackdata->set_head(head);
trackdata->set_sector_size(sectorSize);
trackdata->set_use_fm(fm);
if (fm) {
//trackdata->set_clock_rate_khz(250*300/360);
trackdata->set_idam_byte(0xf57e);
trackdata->set_dam_byte(0xf56f);
}
// create timings to approximately match N88-BASIC
if (sectorSize <= 128) {
trackdata->set_gap0(0x1b);
trackdata->set_gap2(0x09);
trackdata->set_gap3(0x1b);
} else if (sectorSize <= 256) {
trackdata->set_gap0(0x36);
trackdata->set_gap3(0x36);
}
} else if (trackSectorSize != sectorSize) {
Error() << "D88: multiple sector sizes per track are currently unsupported";
}
Bytes data(sectorSize);
inputFile.read((char*) data.begin(), data.size());
const auto& sector = image->put(cylinder, head, sectorId);
@@ -118,6 +152,10 @@ public:
sector->logicalSide = sector->physicalHead = head;
sector->logicalSector = sectorId;
sector->data = data;
sectors->add_sector(sectorId);
if (config.cylinders().end() < cylinder)
config.mutable_cylinders()->set_end(cylinder);
}
}