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Made a bunch of things private in disk.go

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This commit is contained in:
Will Angenent 2018-05-26 23:17:18 +01:00
parent 543bb6925c
commit 2aa16a20f0
1 changed files with 62 additions and 62 deletions
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124
mmu/disk.go
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@ -40,35 +40,35 @@ type disk struct {
var imagePath string // Loaded disk image path var imagePath string // Loaded disk image path
var image disk // A loaded disk image var image disk // A loaded disk image
var imageIsDirty bool // If an image has been written to and needs a flush var imageIsDirty bool // If an image has been written to and needs a flush
var TrackData [trackDataBytes]uint8 // Converted image data as it it returned by the disk controller for a single track var trackData [trackDataBytes]uint8 // Converted image data as it it returned by the disk controller for a single track
// vars to keep track of writes // vars to keep track of writes
const ( const (
WaitingForDataPrologue byte = 1 + iota waitingForDataPrologue byte = 1 + iota
ReceivingData receivingData
) )
const rawDataBufferSize = diskSectorBytes + 16 const rawDataBufferSize = diskSectorBytes + 16
type AddressField struct { type addressField struct {
volume uint8 volume uint8
track uint8 track uint8
sector uint8 sector uint8
} }
var lastReadAddress AddressField var lastReadAddress addressField
var lastReadSectorDataPosition int var lastReadSectorDataPosition int
var SectorWriteState struct { var sectorWriteState struct {
State byte State byte
RawData [rawDataBufferSize]uint8 RawData [rawDataBufferSize]uint8
RawDataPosition uint16 RawDataPosition uint16
Address AddressField Address addressField
} }
func ResetSectorWriteState() { func resetsectorWriteState() {
SectorWriteState.State = WaitingForDataPrologue sectorWriteState.State = waitingForDataPrologue
SectorWriteState.RawDataPosition = 0 sectorWriteState.RawDataPosition = 0
} }
func InitDiskImage() { func InitDiskImage() {
@ -116,7 +116,7 @@ func InitDiskImage() {
sixTwoDecoding[sixTwoEncoding[i]] = i sixTwoDecoding[sixTwoEncoding[i]] = i
} }
ResetSectorWriteState() resetsectorWriteState()
} }
func ReadDiskImage(path string) { func ReadDiskImage(path string) {
@ -230,7 +230,7 @@ func sectorDataDecode(data []uint8) (sector [0x100]uint8) {
func clearTrackData() { func clearTrackData() {
for i := 0; i < trackDataBytes; i++ { for i := 0; i < trackDataBytes; i++ {
TrackData[i] = 0 trackData[i] = 0
} }
} }
@ -247,29 +247,29 @@ func makeSectorData(track uint8, physicalSector uint8) {
csL, csH := oddEvenEncode(checksum) csL, csH := oddEvenEncode(checksum)
// Address field prologue // Address field prologue
TrackData[offset+0] = 0xd5 trackData[offset+0] = 0xd5
TrackData[offset+1] = 0xaa trackData[offset+1] = 0xaa
TrackData[offset+2] = 0x96 trackData[offset+2] = 0x96
// Volume, track, sector and checksum // Volume, track, sector and checksum
TrackData[offset+3] = volL trackData[offset+3] = volL
TrackData[offset+4] = volH trackData[offset+4] = volH
TrackData[offset+5] = trL trackData[offset+5] = trL
TrackData[offset+6] = trH trackData[offset+6] = trH
TrackData[offset+7] = seL trackData[offset+7] = seL
TrackData[offset+8] = seH trackData[offset+8] = seH
TrackData[offset+9] = csL trackData[offset+9] = csL
TrackData[offset+10] = csH trackData[offset+10] = csH
// Address epilogue // Address epilogue
TrackData[offset+11] = 0xde trackData[offset+11] = 0xde
TrackData[offset+12] = 0xaa trackData[offset+12] = 0xaa
TrackData[offset+13] = 0xeb trackData[offset+13] = 0xeb
// Data field prologue // Data field prologue
TrackData[offset+14] = 0xd5 trackData[offset+14] = 0xd5
TrackData[offset+15] = 0xaa trackData[offset+15] = 0xaa
TrackData[offset+16] = 0xad trackData[offset+16] = 0xad
sectorData := sectorDataEncode(image.tracks[track].sectors[logicalSector]) sectorData := sectorDataEncode(image.tracks[track].sectors[logicalSector])
@ -278,17 +278,17 @@ func makeSectorData(track uint8, physicalSector uint8) {
for i := 0; i < 0x56+0x100; i++ { for i := 0; i < 0x56+0x100; i++ {
a ^= sectorData[i] a ^= sectorData[i]
b := sixTwoEncoding[a] b := sixTwoEncoding[a]
TrackData[offset+17+i] = b trackData[offset+17+i] = b
a = sectorData[i] a = sectorData[i]
} }
// Set the checksum byte // Set the checksum byte
TrackData[offset+17+0x56+0x100] = sixTwoEncoding[a] trackData[offset+17+0x56+0x100] = sixTwoEncoding[a]
// Data epilogue // Data epilogue
TrackData[offset+17+0x56+0x100+1] = 0xde trackData[offset+17+0x56+0x100+1] = 0xde
TrackData[offset+17+0x56+0x100+2] = 0xaa trackData[offset+17+0x56+0x100+2] = 0xaa
TrackData[offset+17+0x56+0x100+3] = 0xeb trackData[offset+17+0x56+0x100+3] = 0xeb
} }
func MakeTrackData(armPosition uint8) { func MakeTrackData(armPosition uint8) {
@ -303,14 +303,14 @@ func MakeTrackData(armPosition uint8) {
DriveState.BytePosition = 0 // Point the head at the first sector DriveState.BytePosition = 0 // Point the head at the first sector
// For each sector, encode the data and add it to TrackData // For each sector, encode the data and add it to trackData
for physicalSector := uint8(0); physicalSector < sectorsPerTrack; physicalSector++ { for physicalSector := uint8(0); physicalSector < sectorsPerTrack; physicalSector++ {
makeSectorData(track, physicalSector) makeSectorData(track, physicalSector)
} }
} }
func DecodeAddressField(data []uint8) AddressField { func decodeAddressField(data []uint8) addressField {
var af AddressField var af addressField
af.volume = oddEvenDecode(data[0], data[1]) af.volume = oddEvenDecode(data[0], data[1])
af.track = oddEvenDecode(data[2], data[3]) af.track = oddEvenDecode(data[2], data[3])
af.sector = oddEvenDecode(data[4], data[5]) af.sector = oddEvenDecode(data[4], data[5])
@ -319,15 +319,15 @@ func DecodeAddressField(data []uint8) AddressField {
// Read a byte from the disk head and spin the disk along // Read a byte from the disk head and spin the disk along
func ReadTrackData() (result uint8) { func ReadTrackData() (result uint8) {
result = TrackData[DriveState.BytePosition] result = trackData[DriveState.BytePosition]
if DriveState.BytePosition >= 9 { if DriveState.BytePosition >= 9 {
if TrackData[DriveState.BytePosition-9] == 0xd5 && if trackData[DriveState.BytePosition-9] == 0xd5 &&
TrackData[DriveState.BytePosition-8] == 0xaa && trackData[DriveState.BytePosition-8] == 0xaa &&
TrackData[DriveState.BytePosition-7] == 0x96 { trackData[DriveState.BytePosition-7] == 0x96 {
var addressData []uint8 var addressData []uint8
addressData = TrackData[DriveState.BytePosition-6 : DriveState.BytePosition] addressData = trackData[DriveState.BytePosition-6 : DriveState.BytePosition]
lastReadAddress = DecodeAddressField(addressData) lastReadAddress = decodeAddressField(addressData)
lastReadSectorDataPosition = DriveState.BytePosition + 8 lastReadSectorDataPosition = DriveState.BytePosition + 8
} }
} }
@ -353,32 +353,32 @@ func ReadTrackData() (result uint8) {
// The sector is decoded and updated in memory once the 0x156 data bytes have // The sector is decoded and updated in memory once the 0x156 data bytes have
// been read. The image is flagged as dirty and flushed on exit. // been read. The image is flagged as dirty and flushed on exit.
func WriteTrackData(value uint8) { func WriteTrackData(value uint8) {
if SectorWriteState.State == WaitingForDataPrologue { if sectorWriteState.State == waitingForDataPrologue {
if SectorWriteState.RawDataPosition >= 16 { if sectorWriteState.RawDataPosition >= 16 {
ResetSectorWriteState() resetsectorWriteState()
return return
} }
SectorWriteState.RawData[SectorWriteState.RawDataPosition] = value sectorWriteState.RawData[sectorWriteState.RawDataPosition] = value
SectorWriteState.RawDataPosition += 1 sectorWriteState.RawDataPosition += 1
// Check for address prologue // Check for address prologue
if SectorWriteState.RawDataPosition > 2 && SectorWriteState.RawData[SectorWriteState.RawDataPosition-3] == 0xd5 && if sectorWriteState.RawDataPosition > 2 && sectorWriteState.RawData[sectorWriteState.RawDataPosition-3] == 0xd5 &&
SectorWriteState.RawData[SectorWriteState.RawDataPosition-2] == 0xaa && sectorWriteState.RawData[sectorWriteState.RawDataPosition-2] == 0xaa &&
SectorWriteState.RawData[SectorWriteState.RawDataPosition-1] == 0xad { sectorWriteState.RawData[sectorWriteState.RawDataPosition-1] == 0xad {
// We got it, record the last read address field and reset RawDataPosition // We got it, record the last read address field and reset RawDataPosition
SectorWriteState.State = ReceivingData sectorWriteState.State = receivingData
SectorWriteState.Address = lastReadAddress sectorWriteState.Address = lastReadAddress
SectorWriteState.RawDataPosition = 0 sectorWriteState.RawDataPosition = 0
return return
} }
} else if SectorWriteState.State == ReceivingData { } else if sectorWriteState.State == receivingData {
SectorWriteState.RawData[SectorWriteState.RawDataPosition] = value sectorWriteState.RawData[sectorWriteState.RawDataPosition] = value
SectorWriteState.RawDataPosition += 1 sectorWriteState.RawDataPosition += 1
if SectorWriteState.RawDataPosition == 0x56+0x100 { if sectorWriteState.RawDataPosition == 0x56+0x100 {
// We have the full sector data // We have the full sector data
physicalSector := lastReadAddress.sector physicalSector := lastReadAddress.sector
logicalSector := dos33SectorInterleaving[physicalSector] logicalSector := dos33SectorInterleaving[physicalSector]
@ -386,19 +386,19 @@ func WriteTrackData(value uint8) {
// transform the data from disk bytes to 6-bytes and EOR it // transform the data from disk bytes to 6-bytes and EOR it
a := uint8(0) a := uint8(0)
for i := 0; i < 0x56+0x100; i++ { for i := 0; i < 0x56+0x100; i++ {
b := sixTwoDecoding[SectorWriteState.RawData[i]] b := sixTwoDecoding[sectorWriteState.RawData[i]]
a ^= b a ^= b
SectorWriteState.RawData[i] = a sectorWriteState.RawData[i] = a
} }
// Transform the 0x156 bytes into the final 0x100 bytes // Transform the 0x156 bytes into the final 0x100 bytes
sectorData := sectorDataDecode(SectorWriteState.RawData[0:0x156]) sectorData := sectorDataDecode(sectorWriteState.RawData[0:0x156])
// Save the data to memory & recreate the raw sector data // Save the data to memory & recreate the raw sector data
image.tracks[lastReadAddress.track].sectors[logicalSector].data = sectorData image.tracks[lastReadAddress.track].sectors[logicalSector].data = sectorData
makeSectorData(lastReadAddress.track, physicalSector) makeSectorData(lastReadAddress.track, physicalSector)
ResetSectorWriteState() resetsectorWriteState()
imageIsDirty = true imageIsDirty = true
} }
} }