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Convert the Apple 2 decoder to the new architecture.

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This commit is contained in:
David Given
2019-04-28 20:56:27 +02:00
parent 587f11afdc
commit a2f38ed3fc
3 changed files with 61 additions and 67 deletions
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9
lib/apple2/apple2.h
View File

@@ -10,14 +10,17 @@
class Sector;
class Fluxmap;
class Apple2Decoder : public AbstractSoftSectorDecoder
class Apple2Decoder : public AbstractSplitDecoder
{
public:
virtual ~Apple2Decoder() {}
SectorVector decodeToSectors(const RawRecordVector& rawRecords, unsigned physicalTrack, unsigned physicalSide);
int recordMatcher(uint64_t fifo) const;
nanoseconds_t findSector(FluxmapReader& fmr, Track& track) override;
nanoseconds_t findData(FluxmapReader& fmr, Track& track) override;
void decodeHeader(FluxmapReader& fmr, Track& track, Sector& sector) override;
void decodeData(FluxmapReader& fmr, Track& track, Sector& sector) override;
};
#endif

99
lib/apple2/decoder.cc
View File

@@ -1,5 +1,6 @@
#include "globals.h"
#include "fluxmap.h"
#include "fluxmapreader.h"
#include "protocol.h"
#include "record.h"
#include "decoders.h"
@@ -10,6 +11,10 @@
#include <string.h>
#include <algorithm>
const FluxPattern SECTOR_RECORD_PATTERN(24, APPLE2_SECTOR_RECORD);
const FluxPattern DATA_RECORD_PATTERN(24, APPLE2_DATA_RECORD);
const FluxMatchers SECTOR_OR_DATA_RECORD_PATTERN({ &SECTOR_RECORD_PATTERN, &DATA_RECORD_PATTERN });
static int decode_data_gcr(uint8_t gcr)
{
switch (gcr)
@@ -25,7 +30,7 @@ static int decode_data_gcr(uint8_t gcr)
/* This is extremely inspired by the MESS implementation, written by Nathan Woods
* and R. Belmont: https://github.com/mamedev/mame/blob/7914a6083a3b3a8c243ae6c3b8cb50b023f21e0e/src/lib/formats/ap2_dsk.cpp
*/
static Bytes decode_crazy_data(const uint8_t* inp, int& status)
static Bytes decode_crazy_data(const uint8_t* inp, Sector::Status& status)
{
Bytes output(APPLE2_SECTOR_LENGTH);
@@ -60,61 +65,47 @@ uint8_t combine(uint16_t word)
return word & (word >> 7);
}
SectorVector Apple2Decoder::decodeToSectors(
const RawRecordVector& rawRecords, unsigned, unsigned)
nanoseconds_t Apple2Decoder::findSector(FluxmapReader& fmr, Track& track)
{
std::vector<std::unique_ptr<Sector>> sectors;
int nextTrack;
int nextSector;
bool headerIsValid = false;
for (auto& rawrecord : rawRecords)
{
const std::vector<bool>& rawdata = rawrecord->data;
const Bytes& rawbytes = toBytes(rawdata);
ByteReader br(rawbytes);
if (rawbytes.size() < 8)
continue;
uint32_t signature = br.read_be24();
switch (signature)
{
case APPLE2_SECTOR_RECORD:
{
uint8_t volume = combine(br.read_be16());
nextTrack = combine(br.read_be16());
nextSector = combine(br.read_be16());
uint8_t checksum = combine(br.read_be16());
headerIsValid = checksum == (volume ^ nextTrack ^ nextSector);
break;
}
case APPLE2_DATA_RECORD:
{
if (!headerIsValid)
break;
headerIsValid = false;
Bytes clipped_bytes = rawbytes.slice(0, APPLE2_ENCODED_SECTOR_LENGTH + 5);
int status = Sector::BAD_CHECKSUM;
auto data = decode_crazy_data(&clipped_bytes[3], status);
auto sector = std::unique_ptr<Sector>(
new Sector(status, nextTrack, 0, nextSector, data));
sectors.push_back(std::move(sector));
break;
}
}
}
return sectors;
return fmr.seekToPattern(SECTOR_RECORD_PATTERN);
}
int Apple2Decoder::recordMatcher(uint64_t fifo) const
nanoseconds_t Apple2Decoder::findData(FluxmapReader& fmr, Track& track)
{
uint32_t masked = fifo & 0xffffff;
if ((masked == APPLE2_SECTOR_RECORD) || (masked == APPLE2_DATA_RECORD))
return 24;
return 0;
return fmr.seekToPattern(SECTOR_OR_DATA_RECORD_PATTERN);
}
void Apple2Decoder::decodeHeader(FluxmapReader& fmr, Track& track, Sector& sector)
{
/* Skip ID (as we know it's a APPLE2_SECTOR_RECORD). */
fmr.readRawBits(24, sector.clock);
/* Read header. */
auto header = toBytes(fmr.readRawBits(8*8, sector.clock)).slice(0, 8);
ByteReader br(header);
uint8_t volume = combine(br.read_be16());
sector.logicalTrack = combine(br.read_be16());
sector.logicalSector = combine(br.read_be16());
uint8_t checksum = combine(br.read_be16());
if (checksum == (volume ^ sector.logicalTrack ^ sector.logicalSector))
sector.status = Sector::DATA_MISSING; /* unintuitive but correct */
}
void Apple2Decoder::decodeData(FluxmapReader& fmr, Track& track, Sector& sector)
{
/* Check ID. */
Bytes bytes = toBytes(fmr.readRawBits(3*8, sector.clock)).slice(0, 3);
if (bytes.reader().read_be24() != APPLE2_DATA_RECORD)
return;
/* Read and decode data. */
unsigned recordLength = APPLE2_ENCODED_SECTOR_LENGTH + 2;
bytes = toBytes(fmr.readRawBits(recordLength*8, sector.clock)).slice(0, recordLength);
sector.status = Sector::BAD_CHECKSUM;
sector.data = decode_crazy_data(&bytes[0], sector.status);
}

20
meson.build
View File

@@ -142,15 +142,15 @@ amigadecoderlib = declare_dependency(
include_directories('lib/amiga')
)
#apple2decoderlib = declare_dependency(
# link_with:
# shared_library('apple2decoderlib',
# [ 'lib/apple2/decoder.cc', ],
# dependencies: [fmtlib, felib, decoderlib]),
# include_directories:
# include_directories('lib/apple2')
#)
#
apple2decoderlib = declare_dependency(
link_with:
shared_library('apple2decoderlib',
[ 'lib/apple2/decoder.cc', ],
dependencies: [fmtlib, felib, decoderlib]),
include_directories:
include_directories('lib/apple2')
)
#brotherdecoderlib = declare_dependency(
# link_with:
# shared_library('brotherdecoderlib',
@@ -238,7 +238,7 @@ executable('fe-readadfs', ['src/fe-readadfs.cc'], dependencies
executable('fe-readaeslanier', ['src/fe-readaeslanier.cc'], dependencies: [fmtlib, felib, decoderlib, readerlib, aeslanierdecoderlib])
executable('fe-readamiga', ['src/fe-readamiga.cc'], dependencies: [fmtlib, felib, decoderlib, readerlib, amigadecoderlib])
executable('fe-readampro', ['src/fe-readampro.cc'], dependencies: [fmtlib, felib, decoderlib, readerlib, ibmdecoderlib])
#executable('fe-readapple2', ['src/fe-readapple2.cc'], dependencies: [fmtlib, felib, decoderlib, readerlib, apple2decoderlib])
executable('fe-readapple2', ['src/fe-readapple2.cc'], dependencies: [fmtlib, felib, decoderlib, readerlib, apple2decoderlib])
#executable('fe-readbrother', ['src/fe-readbrother.cc'], dependencies: [fmtlib, felib, decoderlib, readerlib, brotherdecoderlib])
#executable('fe-readc64', ['src/fe-readc64.cc'], dependencies: [fmtlib, felib, decoderlib, readerlib, c64decoderlib])
executable('fe-readdfs', ['src/fe-readdfs.cc'], dependencies: [fmtlib, felib, decoderlib, readerlib, ibmdecoderlib])