izapple2/storage/fileWoz.go
2021-07-01 18:15:49 +02:00

299 lines
7.6 KiB
Go

package storage
import (
"bytes"
"encoding/binary"
"errors"
"fmt"
"strings"
)
/*
See:
https://applesaucefdc.com/woz/
*/
type FileWoz struct {
version int
Info woz2Info
trackMap []uint8
tracks [wozMaxTrack]disketteTrackWoz
meta map[string]string
}
type disketteTrackWoz struct {
bitCount uint32
data []uint8
}
// Structures from the WOZ Disk Image Reference for deserialization
type wozChunkHeader struct {
ID [4]byte
Size uint32
}
type woz1Info struct {
Version uint8
DiskType uint8
WriteProtected uint8
Synchronized uint8
Cleaned uint8
Creator [32]byte
}
type woz2Info struct {
woz1Info
DiskSides uint8
BootSectorFormat uint8
OptimalBitTiming uint8
CompatibleHardware uint16
RequiredRAM uint16
LargestTrack uint16
}
type woz1TrackFooter struct {
BytesUsed uint16
BitCount uint16
SplicePoint uint16
SpliceNibble uint8
SpliceBitCount uint8
Reserved uint16
}
type woz2TrackHeader struct {
StartingBlock uint16
BlockCount uint16
BitCount uint32
}
const (
wozFirstChunkPos = 12
wozChunkHeaderLen = 8
wozMaxTrack = 160
woz1TrackDataSize = 6656
woz1TrackFooterOffset = 6646
woz2TrackBlockSize = 512
woz2FirstTrackBlock = 3 // The bits on the TRKS block start on 3*512
woz2TrackBitsOffset = 1280
)
var headerWoz1 = []uint8{0x57, 0x4f, 0x5A, 0x31, 0xFF, 0x0A, 0x0D, 0x0A}
var headerWoz2 = []uint8{0x57, 0x4f, 0x5A, 0x32, 0xFF, 0x0A, 0x0D, 0x0A}
func (f *FileWoz) GetNextBitAndPosition(position uint32, positionMax uint32, quarterTrack int) (bool, uint32, uint32) {
if positionMax == 0 {
// First unitialised use
positionMax = ^uint32(0) // MaxUint32
}
position++
position %= positionMax
trackIndex := f.trackMap[quarterTrack]
if trackIndex == 0xff {
// No track defined
// TODO: return random value
return false, position, positionMax
}
trackWoz := f.tracks[trackIndex]
if trackWoz.bitCount != positionMax {
// Adjust position as tracks have different length
position = position * trackWoz.bitCount / positionMax
positionMax = trackWoz.bitCount
}
value := (trackWoz.data[position/8] >> (7 - position%8) & 1) == 1
return value, position, positionMax
}
func (f *FileWoz) SetBit(value bool, position uint32, positionMax uint32, quarterTrack int) {
// The position is not moved, GetNextBitAndPosition() would have been called previously.
trackIndex := f.trackMap[quarterTrack]
if trackIndex == 0xff {
// No track defined. Nothing is saved
return
}
trackWoz := f.tracks[trackIndex]
mask := uint8(1) << (7 - position%8)
if value {
trackWoz.data[position/8] |= mask
} else {
trackWoz.data[position/8] &= ^mask
}
fmt.Printf("Saving %v at %v\n", value, position)
}
func isFileWoz(data []uint8) bool {
header := data[:len(headerWoz2)]
if bytes.Equal(headerWoz1, header) {
return true
}
if bytes.Equal(headerWoz2, header) {
return true
}
return false
}
func NewFileWoz(data []uint8) (*FileWoz, error) {
var f FileWoz
// Verify header. Note, the CRC is not verified
header := data[:len(headerWoz2)]
if bytes.Equal(headerWoz1, header) {
f.version = 1
} else if bytes.Equal(headerWoz2, header) {
f.version = 2
} else {
return nil, errors.New("Invalid WOZ header")
}
// Extract the chunks
i := wozFirstChunkPos
var chunkHeader wozChunkHeader
chunks := make(map[string][]uint8)
for i+wozChunkHeaderLen < len(data) {
binary.Read(bytes.NewReader(data[i:]), binary.LittleEndian, &chunkHeader)
i += wozChunkHeaderLen
iNext := i + int(chunkHeader.Size)
if i == iNext || iNext > len(data) {
return nil, errors.New("Invalid chunk in WOZ file")
}
id := string(chunkHeader.ID[:])
chunks[id] = data[i:iNext]
i = iNext
//fmt.Printf("Chunk %v, size %v - %v\n", id, chunkHeader.Size, len(chunks[id]))
}
// Read the INFO chunk
infoData, ok := chunks["INFO"]
if !ok {
return nil, errors.New("Chunk INFO missing from WOZ file")
}
switch f.version {
case 1:
binary.Read(bytes.NewReader(infoData), binary.LittleEndian, &f.Info.woz1Info)
case 2:
binary.Read(bytes.NewReader(infoData), binary.LittleEndian, &f.Info)
}
// Read the optional META chunk
metaData, ok := chunks["META"]
if ok {
f.meta = make(map[string]string)
text := string(metaData)
entries := strings.Split(text, "\n")
for _, entry := range entries {
parts := strings.Split(entry, "\t")
if len(parts) >= 2 {
f.meta[parts[0]] = parts[1]
//fmt.Printf("*** %v: %v\n", parts[0], parts[1])
}
}
}
// Read the TMAP chunk
trackMap, ok := chunks["TMAP"]
if !ok {
return nil, errors.New("Chunk TMAP missing from WOZ file")
}
f.trackMap = trackMap
// Read the TRKS chunk
tracksData, ok := chunks["TRKS"]
if !ok {
return nil, errors.New("Chunk TRKS missing from WOZ file")
}
if f.version == 1 {
i := 0
track := 0
for i+woz1TrackDataSize <= len(tracksData) {
var trackFooter woz1TrackFooter
binary.Read(bytes.NewReader(tracksData[i+woz1TrackFooterOffset:]), binary.LittleEndian, &trackFooter)
f.tracks[track].bitCount = uint32(trackFooter.BitCount)
f.tracks[track].data = tracksData[i : i+int(trackFooter.BytesUsed)]
i += woz1TrackDataSize
track++
}
} else if f.version == 2 {
reader := bytes.NewReader(tracksData)
for i := 0; i < wozMaxTrack; i++ {
var trackHeader woz2TrackHeader
binary.Read(reader, binary.LittleEndian, &trackHeader)
if trackHeader.BitCount != 0 {
f.tracks[i].bitCount = trackHeader.BitCount
dataPos := woz2TrackBlockSize*(int(trackHeader.StartingBlock)-woz2FirstTrackBlock) + woz2TrackBitsOffset
dataSize := woz2TrackBlockSize * int(trackHeader.BlockCount)
//fmt.Printf("@%v %v:%v (%v) of %v\n", trackHeader.StartingBlock, dataPos, dataPos+dataSize, dataSize, len(tracksData))
f.tracks[i].data = tracksData[dataPos : dataPos+dataSize]
}
}
} else {
return nil, errors.New("Woz version not supported")
}
return &f, nil
}
func (f *FileWoz) DumpTrackAsWoz(quarterTrack int) []uint8 {
trackWoz := f.tracks[f.trackMap[quarterTrack]]
return trackWoz.data
}
func (f *FileWoz) DumpTrackAsNib(quarterTrack int) []uint8 {
trackWoz := f.tracks[f.trackMap[quarterTrack]]
out := make([]uint8, 0, trackWoz.bitCount/8)
latch := uint8(0)
for iBit := uint32(0); iBit < trackWoz.bitCount; iBit++ {
bit := trackWoz.data[iBit/8] >> (7 - iBit%8) & 1
latch = (latch << 1) + bit
if latch >= 0x80 {
// Valid reading
out = append(out, latch)
latch = 0
}
}
return out
}
func (f *FileWoz) dump() {
fmt.Printf("Woz image:\n")
fmt.Printf(" Version: %v\n", f.Info.Version)
fmt.Printf(" Disk type: %v\n", f.Info.DiskType)
fmt.Printf(" Write protected: %v\n", f.Info.WriteProtected)
fmt.Printf(" Synchronized: %v\n", f.Info.Synchronized)
fmt.Printf(" Cleaned: %v\n", f.Info.Cleaned)
fmt.Printf(" Creator: %v\n", string(f.Info.Creator[:]))
if f.Info.Version >= 2 {
fmt.Printf(" Disk sides: %v\n", f.Info.DiskSides)
fmt.Printf(" Boot sector format: %v\n", f.Info.BootSectorFormat)
fmt.Printf(" Optimal bit timing: %v ns\n", 125*int(f.Info.OptimalBitTiming))
fmt.Printf(" Compatible hardware: 0x%x\n", f.Info.CompatibleHardware)
fmt.Printf(" Required RAM: %vKB\n", f.Info.RequiredRAM)
fmt.Printf(" Largest track: %v blocks\n", f.Info.LargestTrack)
}
if f.meta != nil {
fmt.Printf(" Metadata:\n")
for k, v := range f.meta {
fmt.Printf(" %v: %v\n", k, v)
}
}
fmt.Printf(" Tracks:\n")
for i, track := range f.trackMap {
if track != 255 {
fmt.Printf(" Track %.2f: %v (%v bits, %v bytes)\n",
0.25*float32(i), track, f.tracks[track].bitCount, len(f.tracks[track].data))
}
}
//nibs := f.dumpTrackAsNib(0)
//fmt.Printf(" Zero track: {%v} %x\n", len(nibs), nibs)
}