Autodetect diskette file format

apple2Setup.go

@@ -105,9 +105,7 @@ func (a *Apple2) AddDisk2(slot int, diskRomFile string, diskImage string) error
 	a.insertCard(&c, slot)
 
 	if diskImage != "" {
-		//diskette, err := loadDisquette(diskImage)
-		//diskette, err := loadDisquetteTimed(diskImage)
-		diskette, err := loadDisquetteWoz(diskImage)
+		diskette, err := loadDisquette(diskImage)
 		if err != nil {
 			return err
 		}

cardDisk2.go

@@ -39,13 +39,6 @@ type cardDisk2Drive struct {
 	tracksStep int   // Stepmotor for tracks position. 4 steps per track
 }
 
-type diskette interface {
-	powerOn(cycle uint64)
-	powerOff(cycle uint64)
-	read(quarterTrack int, cycle uint64) uint8
-	write(quarterTrack int, value uint8, cycle uint64)
-}
-
 const (
 	diskBitCycle           = 4   // There is a dataLatch bit transferred every 4 cycles
 	diskLatchReadCycles    = 7   // Loaded data is available for a little more than 7ns

diskette.go

@@ -0,0 +1,38 @@
+package apple2
+
+import "errors"
+
+type diskette interface {
+	powerOn(cycle uint64)
+	powerOff(cycle uint64)
+	read(quarterTrack int, cycle uint64) uint8
+	write(quarterTrack int, value uint8, cycle uint64)
+}
+
+func loadDisquette(filename string) (diskette, error) {
+	data, err := loadResource(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	if isFileNibOrDsk(data) {
+		f, err := newFileNibOrDsk(data)
+		if err != nil {
+			return nil, err
+		}
+		var d diskette16sector
+		d.nib = f
+		return &d, nil
+	}
+
+	if isFileWoz(data) {
+		f, err := newFileWoz(data)
+		if err != nil {
+			return nil, err
+		}
+
+		return newDisquetteWoz(f)
+	}
+
+	return nil, errors.New("Diskette format not supported")
+}

diskette16sector.go

@@ -11,6 +11,12 @@ type diskette16sector struct {
 	position int
 }
 
+func newDisquette16Sector(f *fileNib) *diskette16sector {
+	var d diskette16sector
+	d.nib = f
+	return &d
+}
+
 func (d *diskette16sector) powerOn(cycle uint64) {
 	// Not used
 }
@@ -31,14 +37,3 @@ func (d *diskette16sector) write(quarterTrack int, value uint8, _ uint64) {
 	d.nib.track[track][d.position] = value
 	d.position = (d.position + 1) % nibBytesPerTrack
 }
-
-func loadDisquette(filename string) (*diskette16sectorTimed, error) {
-	var d diskette16sectorTimed
-
-	f, err := loadNibOrDsk(filename)
-	if err != nil {
-		return nil, err
-	}
-	d.nib = f
-	return &d, nil
-}

diskette16sectorTimed.go

@@ -5,6 +5,12 @@ type diskette16sectorTimed struct {
 	cycleOn uint64 // Cycle when the disk was last turned on
 }
 
+func newDisquette16SectorTimed(f *fileNib) *diskette16sectorTimed {
+	var d diskette16sectorTimed
+	d.nib = f
+	return &d
+}
+
 func (d *diskette16sectorTimed) powerOn(cycle uint64) {
 	d.cycleOn = cycle
 }
@@ -38,15 +44,3 @@ func (d *diskette16sectorTimed) read(quarterTrack int, cycle uint64) uint8 {
 func (d *diskette16sectorTimed) write(quarterTrack int, value uint8, _ uint64) {
 	panic("Write not implemented on time based disk implementation")
 }
-
-func loadDisquetteTimed(filename string) (*diskette16sectorTimed, error) {
-	var d diskette16sectorTimed
-
-	f, err := loadNibOrDsk(filename)
-	if err != nil {
-		return nil, err
-	}
-	d.nib = f
-
-	return &d, nil
-}

disketteWoz.go

@@ -1,6 +1,9 @@
 package apple2
 
-import "math/rand"
+import (
+	"errors"
+	"math/rand"
+)
 
 /*
 See:
@@ -32,7 +35,10 @@ Emulation status for the disk used on the reference:
 	- What is the lifespan of the data latch?
 		- *** First Math Adventures - Understanding Word Problems
 	- Reading Offset Data Streams
-		- Border Zone: Unknown, there is no UI to swap disks
+		- *** Wings of Fury: Not working
+		- Stickybear Town Builder: Working
+	- Optimal bit timing of WOZ 2,0
+		- * Border Zone: Unknown, there is no UI to swap disks
 
 */
 
@@ -52,6 +58,20 @@ type disketteWoz struct {
 	visibleLatchCountDown int8 // The visible latch stores a valid latch reading for 2 bit timings
 }
 
+func newDisquetteWoz(f *fileWoz) (*disketteWoz, error) {
+	// Discard not supported features
+	if f.info.DiskType != 1 {
+		return nil, errors.New("Only 5.25 disks are supported")
+	}
+	if f.info.BootSectorFormat == 2 { // Info not available in WOZ 1.0
+		return nil, errors.New("Woz 13 sector disks are not supported")
+	}
+
+	var d disketteWoz
+	d.data = f
+	return &d, nil
+}
+
 func (d *disketteWoz) powerOn(cycle uint64) {
 	d.turning = true
 	d.cycleOn = cycle
@@ -107,15 +127,3 @@ func (d *disketteWoz) read(quarterTrack int, cycle uint64) uint8 {
 func (d *disketteWoz) write(quarterTrack int, value uint8, _ uint64) {
 	panic("Write not implemented on woz disk implementation")
 }
-
-func loadDisquetteWoz(filename string) (*disketteWoz, error) {
-	var d disketteWoz
-
-	f, err := loadFileWoz(filename)
-	if err != nil {
-		return nil, err
-	}
-	d.data = f
-
-	return &d, nil
-}

fileNib.go

@@ -27,13 +27,23 @@ type fileNib struct {
 	track [numberOfTracks][]byte
 }
 
-func loadNibOrDsk(filename string) (*fileNib, error) {
-	var f fileNib
-
+func loadFileNibOrDsk(filename string) (*fileNib, error) {
 	data, err := loadResource(filename)
 	if err != nil {
 		return nil, err
 	}
+
+	return newFileNibOrDsk(data)
+}
+
+func isFileNibOrDsk(data []uint8) bool {
+	size := len(data)
+	return size == nibImageSize || size == dskImageSize
+}
+
+func newFileNibOrDsk(data []uint8) (*fileNib, error) {
+	var f fileNib
+
 	size := len(data)
 
 	if size == nibImageSize {

fileWoz.go

@@ -87,13 +87,28 @@ func (f *fileWoz) getBit(position uint32, quarterTrack int) uint8 {
 }
 
 func loadFileWoz(filename string) (*fileWoz, error) {
-	var f fileWoz
-
 	data, err := loadResource(filename)
 	if err != nil {
 		return nil, err
 	}
 
+	return newFileWoz(data)
+}
+
+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) {
@@ -192,14 +207,6 @@ func loadFileWoz(filename string) (*fileWoz, error) {
 		return nil, errors.New("Woz version not supported")
 	}
 
-	// Discard not supported features
-	if f.info.DiskType != 1 {
-		return nil, errors.New("Only 5.25 disks are supported")
-	}
-	if f.info.BootSectorFormat == 2 { // Info not available in WOZ 1.0
-		return nil, errors.New("Woz 13 sector disks are not supported")
-	}
-
 	return &f, nil
 }