From 98918d160a8af299cacf4a5a28e4f641a81b5dee Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Sun, 11 Jul 2021 16:12:34 +0200
Subject: [PATCH] Convert the ZilogMcz decoder.

---
 arch/zilogmcz/decoder.cc | 72 ++++++++++++++++++++++++----------------
 arch/zilogmcz/zilogmcz.h | 14 --------
 lib/decoders/decoders.cc | 17 +---------
 3 files changed, 44 insertions(+), 59 deletions(-)

diff --git a/arch/zilogmcz/decoder.cc b/arch/zilogmcz/decoder.cc
index a7692050..6e97a461 100644
--- a/arch/zilogmcz/decoder.cc
+++ b/arch/zilogmcz/decoder.cc
@@ -14,35 +14,49 @@
 
 static const FluxPattern SECTOR_START_PATTERN(16, 0xaaab);
 
-AbstractDecoder::RecordType ZilogMczDecoder::advanceToNextRecord()
+class ZilogMczDecoder : public AbstractDecoder
 {
-	const FluxMatcher* matcher = nullptr;
-    _fmr->seekToIndexMark();
-	_sector->clock = _fmr->seekToPattern(SECTOR_START_PATTERN, matcher);
-	if (matcher == &SECTOR_START_PATTERN)
-		return SECTOR_RECORD;
-	return UNKNOWN_RECORD;
+public:
+	ZilogMczDecoder(const DecoderProto& config):
+		AbstractDecoder(config)
+	{}
+
+    RecordType advanceToNextRecord()
+	{
+		const FluxMatcher* matcher = nullptr;
+		_fmr->seekToIndexMark();
+		_sector->clock = _fmr->seekToPattern(SECTOR_START_PATTERN, matcher);
+		if (matcher == &SECTOR_START_PATTERN)
+			return SECTOR_RECORD;
+		return UNKNOWN_RECORD;
+	}
+
+    void decodeSectorRecord()
+	{
+		readRawBits(14);
+
+		auto rawbits = readRawBits(140*16);
+		auto bytes = decodeFmMfm(rawbits).slice(0, 140);
+		ByteReader br(bytes);
+
+		_sector->logicalSector = br.read_8() & 0x1f;
+		_sector->logicalSide = 0;
+		_sector->logicalTrack = br.read_8() & 0x7f;
+		if (_sector->logicalSector > 31)
+			return;
+		if (_sector->logicalTrack > 80)
+			return;
+
+		_sector->data = br.read(132);
+		uint16_t wantChecksum = br.read_be16();
+		uint16_t gotChecksum = crc16(MODBUS_POLY, 0x0000, bytes.slice(0, 134));
+
+		_sector->status = (wantChecksum == gotChecksum) ? Sector::OK : Sector::BAD_CHECKSUM;
+	}
+};
+
+std::unique_ptr<AbstractDecoder> createZilogMczDecoder(const DecoderProto& config)
+{
+	return std::unique_ptr<AbstractDecoder>(new ZilogMczDecoder(config));
 }
 
-void ZilogMczDecoder::decodeSectorRecord()
-{
-    readRawBits(14);
-
-    auto rawbits = readRawBits(140*16);
-    auto bytes = decodeFmMfm(rawbits).slice(0, 140);
-    ByteReader br(bytes);
-
-    _sector->logicalSector = br.read_8() & 0x1f;
-    _sector->logicalSide = 0;
-    _sector->logicalTrack = br.read_8() & 0x7f;
-    if (_sector->logicalSector > 31)
-        return;
-    if (_sector->logicalTrack > 80)
-        return;
-
-    _sector->data = br.read(132);
-    uint16_t wantChecksum = br.read_be16();
-    uint16_t gotChecksum = crc16(MODBUS_POLY, 0x0000, bytes.slice(0, 134));
-
-    _sector->status = (wantChecksum == gotChecksum) ? Sector::OK : Sector::BAD_CHECKSUM;
-}
diff --git a/arch/zilogmcz/zilogmcz.h b/arch/zilogmcz/zilogmcz.h
index c3070398..4e8a0181 100644
--- a/arch/zilogmcz/zilogmcz.h
+++ b/arch/zilogmcz/zilogmcz.h
@@ -1,20 +1,6 @@
 #ifndef ZILOGMCZ_H
 #define ZILOGMCZ_H
 
-class Sector;
-class Fluxmap;
-class ZilogMczDecoderProto;
-
-class ZilogMczDecoder : public AbstractDecoder
-{
-public:
-	ZilogMczDecoder(const ZilogMczDecoderProto&) {}
-    virtual ~ZilogMczDecoder() {}
-
-    RecordType advanceToNextRecord();
-    void decodeSectorRecord();
-};
-
 extern std::unique_ptr<AbstractDecoder> createZilogMczDecoder(const DecoderProto& config);
 
 #endif
diff --git a/lib/decoders/decoders.cc b/lib/decoders/decoders.cc
index 37139860..d3b6b616 100644
--- a/lib/decoders/decoders.cc
+++ b/lib/decoders/decoders.cc
@@ -47,6 +47,7 @@ std::unique_ptr<AbstractDecoder> AbstractDecoder::create(const DecoderProto& con
 		{ DecoderProto::kNorthstar,  createNorthstarDecoder },
 		{ DecoderProto::kTids990,    createTids990Decoder },
 		{ DecoderProto::kVictor9K,   createVictor9kDecoder },
+		{ DecoderProto::kZilogmcz,   createZilogMczDecoder },
 	};
 
 	auto decoder = decoders.find(config.format_case());
@@ -56,22 +57,6 @@ std::unique_ptr<AbstractDecoder> AbstractDecoder::create(const DecoderProto& con
 	return (decoder->second)(config);
 }
 
-#if 0
-std::unique_ptr<AbstractDecoder> AbstractDecoder::create(const DecoderProto& config)
-{
-	switch (config.format_case())
-	{
-		case DecoderProto::kZilogmcz:
-			return std::unique_ptr<AbstractDecoder>(new ZilogMczDecoder(config.zilogmcz()));
-
-		default:
-			Error() << "no input disk format specified";
-	}
-
-	return std::unique_ptr<AbstractDecoder>();
-}
-#endif
-
 void AbstractDecoder::decodeToSectors(Track& track)
 {
     Sector sector;