Made a bunch of things private in disk.go
This commit is contained in:
Will Angenent
parent
543bb6925c
commit
2aa16a20f0
124
mmu/disk.go
124
mmu/disk.go
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@ -40,35 +40,35 @@ type disk struct {
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var imagePath string // Loaded disk image path
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var image disk // A loaded disk image
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var imageIsDirty bool // If an image has been written to and needs a flush
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var TrackData [trackDataBytes]uint8 // Converted image data as it it returned by the disk controller for a single track
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var trackData [trackDataBytes]uint8 // Converted image data as it it returned by the disk controller for a single track
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// vars to keep track of writes
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const (
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WaitingForDataPrologue byte = 1 + iota
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ReceivingData
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waitingForDataPrologue byte = 1 + iota
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receivingData
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)
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const rawDataBufferSize = diskSectorBytes + 16
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type AddressField struct {
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type addressField struct {
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volume uint8
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track uint8
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sector uint8
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}
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var lastReadAddress AddressField
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var lastReadAddress addressField
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var lastReadSectorDataPosition int
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var SectorWriteState struct {
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var sectorWriteState struct {
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State byte
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RawData [rawDataBufferSize]uint8
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RawDataPosition uint16
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Address AddressField
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Address addressField
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}
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func ResetSectorWriteState() {
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SectorWriteState.State = WaitingForDataPrologue
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SectorWriteState.RawDataPosition = 0
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func resetsectorWriteState() {
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sectorWriteState.State = waitingForDataPrologue
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sectorWriteState.RawDataPosition = 0
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}
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func InitDiskImage() {
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@ -116,7 +116,7 @@ func InitDiskImage() {
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sixTwoDecoding[sixTwoEncoding[i]] = i
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}
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ResetSectorWriteState()
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resetsectorWriteState()
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}
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func ReadDiskImage(path string) {
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@ -230,7 +230,7 @@ func sectorDataDecode(data []uint8) (sector [0x100]uint8) {
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func clearTrackData() {
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for i := 0; i < trackDataBytes; i++ {
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TrackData[i] = 0
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trackData[i] = 0
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}
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}
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@ -247,29 +247,29 @@ func makeSectorData(track uint8, physicalSector uint8) {
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csL, csH := oddEvenEncode(checksum)
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// Address field prologue
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TrackData[offset+0] = 0xd5
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TrackData[offset+1] = 0xaa
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TrackData[offset+2] = 0x96
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trackData[offset+0] = 0xd5
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trackData[offset+1] = 0xaa
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trackData[offset+2] = 0x96
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// Volume, track, sector and checksum
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TrackData[offset+3] = volL
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TrackData[offset+4] = volH
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TrackData[offset+5] = trL
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TrackData[offset+6] = trH
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TrackData[offset+7] = seL
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TrackData[offset+8] = seH
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TrackData[offset+9] = csL
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TrackData[offset+10] = csH
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trackData[offset+3] = volL
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trackData[offset+4] = volH
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trackData[offset+5] = trL
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trackData[offset+6] = trH
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trackData[offset+7] = seL
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trackData[offset+8] = seH
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trackData[offset+9] = csL
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trackData[offset+10] = csH
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// Address epilogue
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TrackData[offset+11] = 0xde
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TrackData[offset+12] = 0xaa
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TrackData[offset+13] = 0xeb
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trackData[offset+11] = 0xde
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trackData[offset+12] = 0xaa
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trackData[offset+13] = 0xeb
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// Data field prologue
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TrackData[offset+14] = 0xd5
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TrackData[offset+15] = 0xaa
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TrackData[offset+16] = 0xad
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trackData[offset+14] = 0xd5
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trackData[offset+15] = 0xaa
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trackData[offset+16] = 0xad
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sectorData := sectorDataEncode(image.tracks[track].sectors[logicalSector])
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@ -278,17 +278,17 @@ func makeSectorData(track uint8, physicalSector uint8) {
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for i := 0; i < 0x56+0x100; i++ {
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a ^= sectorData[i]
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b := sixTwoEncoding[a]
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TrackData[offset+17+i] = b
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trackData[offset+17+i] = b
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a = sectorData[i]
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}
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// Set the checksum byte
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TrackData[offset+17+0x56+0x100] = sixTwoEncoding[a]
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trackData[offset+17+0x56+0x100] = sixTwoEncoding[a]
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// Data epilogue
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TrackData[offset+17+0x56+0x100+1] = 0xde
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TrackData[offset+17+0x56+0x100+2] = 0xaa
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TrackData[offset+17+0x56+0x100+3] = 0xeb
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trackData[offset+17+0x56+0x100+1] = 0xde
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trackData[offset+17+0x56+0x100+2] = 0xaa
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trackData[offset+17+0x56+0x100+3] = 0xeb
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}
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func MakeTrackData(armPosition uint8) {
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@ -303,14 +303,14 @@ func MakeTrackData(armPosition uint8) {
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DriveState.BytePosition = 0 // Point the head at the first sector
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// For each sector, encode the data and add it to TrackData
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// For each sector, encode the data and add it to trackData
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for physicalSector := uint8(0); physicalSector < sectorsPerTrack; physicalSector++ {
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makeSectorData(track, physicalSector)
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}
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}
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func DecodeAddressField(data []uint8) AddressField {
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var af AddressField
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func decodeAddressField(data []uint8) addressField {
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var af addressField
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af.volume = oddEvenDecode(data[0], data[1])
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af.track = oddEvenDecode(data[2], data[3])
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af.sector = oddEvenDecode(data[4], data[5])
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@ -319,15 +319,15 @@ func DecodeAddressField(data []uint8) AddressField {
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// Read a byte from the disk head and spin the disk along
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func ReadTrackData() (result uint8) {
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result = TrackData[DriveState.BytePosition]
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result = trackData[DriveState.BytePosition]
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if DriveState.BytePosition >= 9 {
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if TrackData[DriveState.BytePosition-9] == 0xd5 &&
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TrackData[DriveState.BytePosition-8] == 0xaa &&
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TrackData[DriveState.BytePosition-7] == 0x96 {
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if trackData[DriveState.BytePosition-9] == 0xd5 &&
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trackData[DriveState.BytePosition-8] == 0xaa &&
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trackData[DriveState.BytePosition-7] == 0x96 {
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var addressData []uint8
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addressData = TrackData[DriveState.BytePosition-6 : DriveState.BytePosition]
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lastReadAddress = DecodeAddressField(addressData)
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addressData = trackData[DriveState.BytePosition-6 : DriveState.BytePosition]
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lastReadAddress = decodeAddressField(addressData)
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lastReadSectorDataPosition = DriveState.BytePosition + 8
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}
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}
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@ -353,32 +353,32 @@ func ReadTrackData() (result uint8) {
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// The sector is decoded and updated in memory once the 0x156 data bytes have
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// been read. The image is flagged as dirty and flushed on exit.
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func WriteTrackData(value uint8) {
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if SectorWriteState.State == WaitingForDataPrologue {
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if SectorWriteState.RawDataPosition >= 16 {
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ResetSectorWriteState()
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if sectorWriteState.State == waitingForDataPrologue {
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if sectorWriteState.RawDataPosition >= 16 {
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resetsectorWriteState()
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return
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}
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SectorWriteState.RawData[SectorWriteState.RawDataPosition] = value
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SectorWriteState.RawDataPosition += 1
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sectorWriteState.RawData[sectorWriteState.RawDataPosition] = value
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sectorWriteState.RawDataPosition += 1
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// Check for address prologue
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if SectorWriteState.RawDataPosition > 2 && SectorWriteState.RawData[SectorWriteState.RawDataPosition-3] == 0xd5 &&
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SectorWriteState.RawData[SectorWriteState.RawDataPosition-2] == 0xaa &&
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SectorWriteState.RawData[SectorWriteState.RawDataPosition-1] == 0xad {
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if sectorWriteState.RawDataPosition > 2 && sectorWriteState.RawData[sectorWriteState.RawDataPosition-3] == 0xd5 &&
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sectorWriteState.RawData[sectorWriteState.RawDataPosition-2] == 0xaa &&
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sectorWriteState.RawData[sectorWriteState.RawDataPosition-1] == 0xad {
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// We got it, record the last read address field and reset RawDataPosition
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SectorWriteState.State = ReceivingData
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SectorWriteState.Address = lastReadAddress
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SectorWriteState.RawDataPosition = 0
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sectorWriteState.State = receivingData
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sectorWriteState.Address = lastReadAddress
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sectorWriteState.RawDataPosition = 0
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return
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}
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} else if SectorWriteState.State == ReceivingData {
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SectorWriteState.RawData[SectorWriteState.RawDataPosition] = value
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SectorWriteState.RawDataPosition += 1
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} else if sectorWriteState.State == receivingData {
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sectorWriteState.RawData[sectorWriteState.RawDataPosition] = value
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sectorWriteState.RawDataPosition += 1
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if SectorWriteState.RawDataPosition == 0x56+0x100 {
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if sectorWriteState.RawDataPosition == 0x56+0x100 {
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// We have the full sector data
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physicalSector := lastReadAddress.sector
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logicalSector := dos33SectorInterleaving[physicalSector]
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@ -386,19 +386,19 @@ func WriteTrackData(value uint8) {
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// transform the data from disk bytes to 6-bytes and EOR it
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a := uint8(0)
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for i := 0; i < 0x56+0x100; i++ {
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b := sixTwoDecoding[SectorWriteState.RawData[i]]
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b := sixTwoDecoding[sectorWriteState.RawData[i]]
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a ^= b
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SectorWriteState.RawData[i] = a
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sectorWriteState.RawData[i] = a
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}
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// Transform the 0x156 bytes into the final 0x100 bytes
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sectorData := sectorDataDecode(SectorWriteState.RawData[0:0x156])
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sectorData := sectorDataDecode(sectorWriteState.RawData[0:0x156])
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// Save the data to memory & recreate the raw sector data
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image.tracks[lastReadAddress.track].sectors[logicalSector].data = sectorData
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makeSectorData(lastReadAddress.track, physicalSector)
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ResetSectorWriteState()
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resetsectorWriteState()
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imageIsDirty = true
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}
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}
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