Split the encoder's use of clock and bitcell, as for FM/MFM they're different

things; make the FM/MFM decoders use twice the bitcell for the clock.

arch/aeslanier/decoder.cc

@@ -32,8 +32,9 @@ public:
 
     RecordType advanceToNextRecord()
 	{
-		_sector->clock = _fmr->seekToPattern(SECTOR_PATTERN);
-		if (_fmr->eof() || !_sector->clock)
+		_sector->bitcell = _fmr->seekToPattern(SECTOR_PATTERN);
+		_sector->clock = _sector->bitcell * 2;
+		if (_fmr->eof() || !_sector->bitcell)
 			return UNKNOWN_RECORD;
 		return SECTOR_RECORD;
 	}

arch/amiga/decoder.cc

@@ -31,8 +31,9 @@ public:
 
     RecordType advanceToNextRecord() override
 	{
-		_sector->clock = _fmr->seekToPattern(SECTOR_PATTERN);
-		if (_fmr->eof() || !_sector->clock)
+		_sector->bitcell = _fmr->seekToPattern(SECTOR_PATTERN);
+		_sector->clock = _sector->bitcell * 2;
+		if (_fmr->eof() || !_sector->bitcell)
 			return UNKNOWN_RECORD;
 		return SECTOR_RECORD;
 	}

arch/apple2/decoder.cc

@@ -74,7 +74,7 @@ public:
     RecordType advanceToNextRecord()
 	{
 		const FluxMatcher* matcher = nullptr;
-		_sector->clock = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
+		_sector->clock = _sector->bitcell = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
 		if (matcher == &SECTOR_RECORD_PATTERN)
 			return RecordType::SECTOR_RECORD;
 		if (matcher == &DATA_RECORD_PATTERN)

arch/brother/decoder.cc

@@ -63,7 +63,7 @@ public:
     RecordType advanceToNextRecord()
 	{
 		const FluxMatcher* matcher = nullptr;
-		_sector->clock = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
+		_sector->clock = _sector->bitcell = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
 		if (matcher == &SECTOR_RECORD_PATTERN)
 			return RecordType::SECTOR_RECORD;
 		if (matcher == &DATA_RECORD_PATTERN)

arch/c64/decoder.cc

@@ -61,7 +61,7 @@ public:
     RecordType advanceToNextRecord()
 	{
 		const FluxMatcher* matcher = nullptr;
-		_sector->clock = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
+		_sector->clock = _sector->bitcell = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
 		if (matcher == &SECTOR_RECORD_PATTERN)
 			return RecordType::SECTOR_RECORD;
 		if (matcher == &DATA_RECORD_PATTERN)

arch/f85/decoder.cc

@@ -61,7 +61,7 @@ public:
     RecordType advanceToNextRecord()
 	{
 		const FluxMatcher* matcher = nullptr;
-		_sector->clock = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
+		_sector->clock = _sector->bitcell = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
 		if (matcher == &SECTOR_RECORD_PATTERN)
 			return RecordType::SECTOR_RECORD;
 		if (matcher == &DATA_RECORD_PATTERN)

arch/fb100/decoder.cc

@@ -107,7 +107,8 @@ public:
     RecordType advanceToNextRecord()
 	{
 		const FluxMatcher* matcher = nullptr;
-		_sector->clock = _fmr->seekToPattern(SECTOR_ID_PATTERN, matcher);
+		_sector->bitcell = _fmr->seekToPattern(SECTOR_ID_PATTERN, matcher);
+		_sector->clock = _sector->bitcell * 2;
 		if (matcher == &SECTOR_ID_PATTERN)
 			return RecordType::SECTOR_RECORD;
 		return RecordType::UNKNOWN_RECORD;

arch/ibm/decoder.cc

@@ -101,7 +101,8 @@ public:
     RecordType advanceToNextRecord() override
 	{
 		const FluxMatcher* matcher = nullptr;
-		_sector->clock = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
+		_sector->bitcell = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
+		_sector->clock = _sector->bitcell * 2;
 
 		/* If this is the MFM prefix byte, the the decoder is going to expect three
 		 * extra bytes on the front of the header. */

arch/ibm/encoder.cc

@@ -133,11 +133,17 @@ public:
 				encodeMfm(_bits, _cursor, bytes, _lastBit);
 		};
 
+		auto writeFillerRawBytes = [&](int count, uint16_t byte)
+		{
+			for (int i=0; i<count; i++)
+				writeRawBits(byte, 16);
+		};
+
 		auto writeFillerBytes = [&](int count, uint8_t byte)
 		{
-			Bytes bytes = { byte };
+			Bytes b { byte };
 			for (int i=0; i<count; i++)
-				writeBytes(bytes);
+				writeBytes(b);
 		};
 
 		double clockRateUs = 1e3 / trackdata.clock_rate_khz();
@@ -160,9 +166,9 @@ public:
 			}
 		}
 
-		uint8_t gapFill = trackdata.use_fm() ? 0x00 : 0x4e;
+		uint16_t gapFill = trackdata.gap_fill_byte();
 
-		writeFillerBytes(trackdata.gap0(), gapFill);
+		writeFillerRawBytes(trackdata.gap0(), gapFill);
 		if (trackdata.emit_iam())
 		{
 			writeFillerBytes(trackdata.use_fm() ? 6 : 12, 0x00);
@@ -172,7 +178,7 @@ public:
 					writeRawBits(MFM_IAM_SEPARATOR, 16);
 			}
 			writeRawBits(trackdata.use_fm() ? FM_IAM_RECORD : MFM_IAM_RECORD, 16);
-			writeFillerBytes(trackdata.gap1(), gapFill);
+			writeFillerRawBytes(trackdata.gap1(), gapFill);
 		}
 
 		int logicalSide = physicalSide ^ trackdata.swap_sides();
@@ -180,7 +186,7 @@ public:
 		for (int sectorId : trackdata.sectors().sector())
 		{
 			if (!first)
-				writeFillerBytes(trackdata.gap3(), gapFill);
+				writeFillerRawBytes(trackdata.gap3(), gapFill);
 			first = false;
 
 			const auto& sectorData = image.get(physicalTrack, logicalSide, sectorId);
@@ -227,7 +233,7 @@ public:
 				writeBytes(header.slice(conventionalHeaderStart));
 			}
 
-			writeFillerBytes(trackdata.gap2(), gapFill);
+			writeFillerRawBytes(trackdata.gap2(), gapFill);
 
 			{
 				Bytes data;
@@ -264,7 +270,7 @@ public:
 		if (_cursor >= _bits.size())
 			Error() << "track data overrun";
 		while (_cursor < _bits.size())
-			writeFillerBytes(1, gapFill);
+			writeFillerRawBytes(1, gapFill);
 
 		std::unique_ptr<Fluxmap> fluxmap(new Fluxmap);
 		fluxmap->appendBits(_bits, clockRateUs*1e3);

arch/ibm/ibm.proto

@@ -15,7 +15,7 @@ message IbmDecoderProto {
 }
 
 message IbmEncoderProto {
-	// Next: 18
+	// Next: 19
 	message TrackdataProto {
 		message SectorsProto {
 			repeated int32 sector = 1		[(help) = "write these sectors (in order) on each track"];
@@ -37,6 +37,7 @@ message IbmEncoderProto {
 		optional int32 gap3 = 12            [default=80, (help) = "size of gap 4 (the post-data or format gap)"];
 		optional bool swap_sides = 14       [default=false, (help) = "swap side bytes when writing"];
 		optional SectorsProto sectors = 17	[(help) = "write these sectors (in order) on each track"];
+		optional int32 gap_fill_byte = 18   [default=0x9254, (help) = "16-bit raw bit pattern of gap fill byte"];
 	}
 
 	repeated TrackdataProto trackdata = 1;

arch/macintosh/decoder.cc

@@ -132,7 +132,7 @@ public:
     RecordType advanceToNextRecord()
 	{
 		const FluxMatcher* matcher = nullptr;
-		_sector->clock = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
+		_sector->clock = _sector->bitcell = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
 		if (matcher == &SECTOR_RECORD_PATTERN)
 			return SECTOR_RECORD;
 		if (matcher == &DATA_RECORD_PATTERN)

arch/micropolis/decoder.cc

@@ -35,9 +35,9 @@ public:
 	{
 		_fmr->seekToIndexMark();
 		const FluxMatcher* matcher = nullptr;
-		_sector->clock = _fmr->seekToPattern(SECTOR_SYNC_PATTERN, matcher);
+		_sector->bitcell = _fmr->seekToPattern(SECTOR_SYNC_PATTERN, matcher);
+		_sector->clock = _sector->bitcell * 2;
 		if (matcher == &SECTOR_SYNC_PATTERN) {
-			readRawBits(16);
 			return SECTOR_RECORD;
 		}
 		return UNKNOWN_RECORD;
@@ -45,6 +45,7 @@ public:
 
 	void decodeSectorRecord()
 	{
+		readRawBits(16);
 		auto rawbits = readRawBits(MICROPOLIS_ENCODED_SECTOR_SIZE*16);
 		auto bytes = decodeFmMfm(rawbits).slice(0, MICROPOLIS_ENCODED_SECTOR_SIZE);
 		ByteReader br(bytes);

arch/mx/decoder.cc

@@ -31,7 +31,7 @@ public:
     void beginTrack()
 	{
 		_currentSector = -1;
-		_clock = 0;
+		_bitcell = 0;
 	}
 
     RecordType advanceToNextRecord()
@@ -40,8 +40,9 @@ public:
 		{
 			/* First sector in the track: look for the sync marker. */
 			const FluxMatcher* matcher = nullptr;
-			_sector->clock = _clock = _fmr->seekToPattern(ID_PATTERN, matcher);
-			readRawBits(32); /* skip the ID mark */
+			_sector->bitcell = _bitcell = _fmr->seekToPattern(ID_PATTERN, matcher);
+			_sector->clock = _sector->bitcell * 2;
+			 readRawBits(32); /* skip the ID mark */
 			_logicalTrack = decodeFmMfm(readRawBits(32)).slice(0, 32).reader().read_be16();
 		}
 		else if (_currentSector == 10)
@@ -54,7 +55,7 @@ public:
 			/* Otherwise we assume the clock from the first sector is still valid.
 			 * The decoder framwork will automatically stop when we hit the end of
 			 * the track. */
-			_sector->clock = _clock;
+			_sector->bitcell = _bitcell;
 		}
 
 		_currentSector++;
@@ -80,7 +81,7 @@ public:
 	}
 
 private:
-    nanoseconds_t _clock;
+    nanoseconds_t _bitcell;
     int _currentSector;
     int _logicalTrack;
 };

arch/northstar/decoder.cc

@@ -105,7 +105,8 @@ public:
 		 * past one or more sector pulses.  For this reason, calculate
 		 * _hardSectorId after the sector header is found.
 		 */
-		_sector->clock = _fmr->seekToPattern(ANY_SECTOR_PATTERN, matcher);
+		_sector->bitcell = _fmr->seekToPattern(ANY_SECTOR_PATTERN, matcher);
+		_sector->clock = _sector->bitcell * 2;
 
 		int sectorFoundTimeRaw = std::round((_fmr->tell().ns()) / 1e6);
 		int sectorFoundTime;

arch/tids990/decoder.cc

@@ -48,7 +48,8 @@ public:
     RecordType advanceToNextRecord()
 	{
 		const FluxMatcher* matcher = nullptr;
-		_sector->clock = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
+		_sector->bitcell = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
+		_sector->clock = _sector->bitcell * 2;
 		if (matcher == &SECTOR_RECORD_PATTERN)
 			return RecordType::SECTOR_RECORD;
 		if (matcher == &DATA_RECORD_PATTERN)

arch/victor9k/decoder.cc

@@ -62,7 +62,7 @@ public:
     RecordType advanceToNextRecord()
 	{
 		const FluxMatcher* matcher = nullptr;
-		_sector->clock = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
+		_sector->clock = _sector->bitcell = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
 		if (matcher == &SECTOR_RECORD_PATTERN)
 			return SECTOR_RECORD;
 		if (matcher == &DATA_RECORD_PATTERN)

arch/zilogmcz/decoder.cc

@@ -24,7 +24,8 @@ public:
 	{
 		const FluxMatcher* matcher = nullptr;
 		_fmr->seekToIndexMark();
-		_sector->clock = _fmr->seekToPattern(SECTOR_START_PATTERN, matcher);
+		_sector->bitcell = _fmr->seekToPattern(SECTOR_START_PATTERN, matcher);
+		_sector->clock = _sector->bitcell * 2;
 		if (matcher == &SECTOR_START_PATTERN)
 			return SECTOR_RECORD;
 		return UNKNOWN_RECORD;

lib/decoders/decoders.cc

@@ -77,9 +77,9 @@ std::unique_ptr<TrackDataFlux> AbstractDecoder::decodeToSectors(
 		_sector->physicalHead = physicalHead;
 
         Fluxmap::Position recordStart = fmr.tell();
-		_decoder.reset(new FluxDecoder(&fmr, _sector->clock, _config));
+		_decoder.reset(new FluxDecoder(&fmr, _sector->bitcell, _config));
         RecordType r = advanceToNextRecord();
-        if (fmr.eof() || !_sector->clock)
+        if (fmr.eof() || !_sector->bitcell)
             return std::move(_trackdata);
         if ((r == UNKNOWN_RECORD) || (r == DATA_RECORD))
         {
@@ -134,17 +134,17 @@ void AbstractDecoder::pushRecord(const Fluxmap::Position& start, const Fluxmap::
 	
 	record->startTime = start.ns();
 	record->endTime = end.ns();
-    record->clock = _sector->clock;
+    record->bitcell = _sector->bitcell;
 
     _fmr->seek(start);
-	FluxDecoder decoder(_fmr, _sector->clock, _config);
+	FluxDecoder decoder(_fmr, _sector->bitcell, _config);
     record->rawData = toBytes(decoder.readBits(end));
     _fmr->seek(here);
 }
 
 void AbstractDecoder::resetFluxDecoder()
 {
-	_decoder.reset(new FluxDecoder(_fmr, _sector->clock, _config));
+	_decoder.reset(new FluxDecoder(_fmr, _sector->bitcell, _config));
 }
 
 std::vector<bool> AbstractDecoder::readRawBits(unsigned count)

lib/flux.h

@@ -6,7 +6,7 @@ class Image;
 
 struct Record
 {
-	nanoseconds_t clock = 0;
+	nanoseconds_t bitcell = 0;
 	nanoseconds_t startTime = 0;
 	nanoseconds_t endTime = 0;
 	Bytes rawData;

lib/imagereader/d88imagereader.cc

@@ -127,7 +127,7 @@ public:
                     trackdata->set_sector_size(sectorSize);
                     trackdata->set_use_fm(fm);
                     if (fm) {
-                        //trackdata->set_clock_rate_khz(250*300/360);
+                        trackdata->set_gap_fill_byte(0xffff);
                         trackdata->set_idam_byte(0xf57e);
                         trackdata->set_dam_byte(0xf56f);
                     }

lib/reader.cc

@@ -156,9 +156,9 @@ void readDiskCommand(FluxSource& fluxsource, AbstractDecoder& decoder, ImageWrit
 				std::cout << "\nRaw (undecoded) records follow:\n\n";
 				for (const auto& record : track_records)
 				{
-					std::cout << fmt::format("I+{:.2f}us with {:.2f}us clock\n",
+					std::cout << fmt::format("I+{:.2f}us with {:.2f}us bitcell\n",
 								record->startTime / 1000.0,
-								record->clock / 1000.0);
+								record->bitcell / 1000.0);
 					hexdump(std::cout, record->rawData);
 					std::cout << std::endl;
 				}

lib/sector.h

@@ -28,6 +28,7 @@ public:
 	Status status = Status::INTERNAL_ERROR;
     Fluxmap::Position position;
     nanoseconds_t clock = 0;
+    nanoseconds_t bitcell = 0;
     nanoseconds_t headerStartTime = 0;
     nanoseconds_t headerEndTime = 0;
     nanoseconds_t dataStartTime = 0;