Read only ProDOS hard disk support.

README.md

@@ -9,11 +9,13 @@ Portable emulator of an Apple II+. Written in Go.
 - Apple II+ with 48Kb of base RAM
 - Sound
 - 16 Sector diskettes in DSK format
+- ProDos hard disk (read only, just to support [Total Replay](https://archive.org/details/TotalReplay))
 - Emulated extension cards:
     - DiskII controller
     - 16Kb Language Card
     - 256Kb Saturn RAM 
     - ThunderClock Plus real time clock
+    - Simulated bootable hard disk card
 - Graphic modes:
     - Text, Lores and Hires
 - Displays:
@@ -47,6 +49,13 @@ casa@servidor:~$ ./apple2sdl -disk "https://www.apple.asimov.net/images/games/ac
 ```
 ![Karateka](doc/karateka.png)
 
+### Play the Total Replay collection
+Download the excellent [Total Replay](https://archive.org/details/TotalReplay) compilation by
+[a2-4am](https://github.com/a2-4am/4cade). Run it with the `-hd` parameter:
+```
+casa@servidor:~$ ./apple2sdl -hd "Total Replay v2.0.2mg"
+```
+![Total Replay](doc/totalreplay.png)
 
 ### Terminal mode
 To run text mode right on the terminal without the SDL2 dependency, use `apple2console`. It runs on the console using ANSI escape codes. Input is sent to the emulated Apple II one line at a time: 
@@ -112,6 +121,10 @@ Only valid on SDL mode
         shows the character map
   -fastDisk
         set fast mode when the disks are spinning (default true)
+  -hd string
+        file to load on the hard disk
+  -hdSlot int
+        slot for the hard drive if present. -1 for none. (default -1)
   -languageCardSlot int
         slot for the 16kb language card. -1 for none
   -mhz float
@@ -127,7 +140,7 @@ Only valid on SDL mode
   -thunderClockCardSlot int
         slot for the ThunderClock Plus card. -1 for none (default 5)
   -traceCpu
-        dump to the console the CPU execution 
+        dump to the console the CPU execution. Use F11 to toggle.
   -traceSS
         dump to the console the sofswitches calls
 

apple2Setup.go

@@ -64,10 +64,10 @@ func (a *Apple2) LoadRom(filename string) {
 	mmu.resetRomPaging()
 }
 
-// AddDisk2 insterts a DiskII controller
+// AddDisk2 inserts a DiskII controller
 func (a *Apple2) AddDisk2(slot int, diskRomFile string, diskImage string) {
 	var c cardDisk2
-	c.loadRom(diskRomFile)
+	c.loadRom(loadResource(diskRomFile))
 	a.insertCard(&c, slot)
 
 	if diskImage != "" {
@@ -77,6 +77,16 @@ func (a *Apple2) AddDisk2(slot int, diskRomFile string, diskImage string) {
 	}
 }
 
+// AddHardDisk adds a ProDos hard dirve with a 2MG image
+func (a *Apple2) AddHardDisk(slot int, hdImage string) {
+	var c cardHardDisk
+	c.loadRom(buildHardDiskRom(slot))
+	a.insertCard(&c, slot)
+
+	hd := loadHardDisk2mg(hdImage)
+	c.addDisk(hd)
+}
+
 // AddLanguageCard inserts a 16Kb card
 func (a *Apple2) AddLanguageCard(slot int) {
 	a.insertCard(&cardLanguage{}, slot)
@@ -90,7 +100,7 @@ func (a *Apple2) AddSaturnCard(slot int) {
 // AddThunderClockPlusCard inserts a ThunderClock Plus clock card
 func (a *Apple2) AddThunderClockPlusCard(slot int, romFile string) {
 	var c cardThunderClockPlus
-	c.loadRom(romFile)
+	c.loadRom(loadResource(romFile))
 	a.insertCard(&c, slot)
 }
 

apple2main.go

@@ -23,6 +23,14 @@ func MainApple() *Apple2 {
 		"disk",
 		"<internal>/dos33.dsk",
 		"file to load on the first disk drive")
+	hardDiskImage := flag.String(
+		"hd",
+		"",
+		"file to load on the hard disk")
+	hardDiskSlot := flag.Int(
+		"hdSlot",
+		-1,
+		"slot for the hard drive if present. -1 for none.")
 	cpuClock := flag.Float64(
 		"mhz",
 		CpuClockMhz,
@@ -100,9 +108,16 @@ func MainApple() *Apple2 {
 	if *thunderClockCardSlot > 0 {
 		a.AddThunderClockPlusCard(*thunderClockCardSlot, "<internal>/ThunderclockPlusROM.bin")
 	}
-	if *disk2Slot >= 0 {
+	if *disk2Slot > 0 {
 		a.AddDisk2(*disk2Slot, *disk2RomFile, *diskImage)
 	}
+	if *hardDiskImage != "" {
+		if *hardDiskSlot <= 0 {
+			// If there is a hard disk image, but no slot assigned, use slot 7.
+			*hardDiskSlot = 7
+		}
+		a.AddHardDisk(*hardDiskSlot, *hardDiskImage)
+	}
 
 	//a.AddCardInOut(2)
 	//a.AddCardLogger(4)

cardBase.go

@@ -5,7 +5,7 @@ import (
 )
 
 type card interface {
-	loadRom(filename string)
+	loadRom(data []uint8)
 	assign(a *Apple2, slot int)
 	persistent
 }
@@ -19,11 +19,10 @@ type cardBase struct {
 	ssw      [16]softSwitchW
 }
 
-func (c *cardBase) loadRom(filename string) {
+func (c *cardBase) loadRom(data []uint8) {
 	if c.a != nil {
 		panic("Rom must be loaded before inserting the card in the slot")
 	}
-	data := loadResource(filename)
 	if len(data) >= 0x100 {
 		c.rom = newMemoryRange(0, data)
 	}

cardHardDisk.go

@@ -0,0 +1,116 @@
+package apple2
+
+/*
+To implement a hard drive we just have to support boot from #PR7 and the PRODOS expextations.
+See Beneath Prodos, section 6-6, 7-13 and 5-8. (http://www.apple-iigs.info/doc/fichiers/beneathprodos.pdf)
+*/
+
+type cardHardDisk struct {
+	cardBase
+	disk *hardDisk
+}
+
+func buildHardDiskRom(slot int) []uint8 {
+	data := make([]uint8, 256)
+	ssBase := 0x80 + uint8(slot<<4)
+
+	copy(data, []uint8{
+		// Preamble bytes to comply with the expectation in $Cn01, 3, 5 and 7
+		0xa9, 0x20, // LDA #$20
+		0xa9, 0x00, // LDA #$20
+		0xa9, 0x03, // LDA #$20
+		0xa9, 0x3c, // LDA #$3c
+
+		// Boot code: SS will load block 0 in address $0800. The jump there.
+		// Note: on execution the first block expects $42 to $47 to have
+		// valid values to read block 0. At least Total Replay expects that.
+		0xa9, 0x01, // LDA·#$01
+		0x85, 0x42, // STA $42 ; Command READ(1)
+		0xa9, 0x00, // LDA·#$00
+		0x85, 0x43, // STA $43 ; Unit 0
+		0x85, 0x44, // STA $44 ; Dest LO($0800)
+		0x85, 0x46, // STA $46 ; Block LO(0)
+		0x85, 0x47, // STA $47 ; Block HI(0)
+		0xa9, 0x08, // LDA·#$08
+		0x85, 0x45, // STA $45 ; Dest HI($0800)
+
+		0xad, ssBase, 0xc0, // LDA $C0n1 ;Call to softswitch 0.
+		0xa2, uint8(slot << 4), // LDX $s7 ;Slot on hign nibble of X
+		0x4c, 0x01, 0x08, // JMP $801
+	})
+
+	copy(data[0x80:], []uint8{
+		0xad, ssBase + 0, 0xc0, // LDA $C0n0 ; Softswitch 0, execute command. Error code in reg A.
+		0xae, ssBase + 1, 0xc0, // LDX $C0n1 ; Softswitch 2, LO(Blocks), STATUS needs that in reg X.
+		0xac, ssBase + 2, 0xc0, // LDY $C0n2 ; Softswitch 3, HI(Blocks). STATUS needs that in reg Y.
+		0x18, // CLC ; Clear carry for no errors.
+		0x60, // RTS
+	})
+
+	data[0xfc] = 0
+	data[0xfd] = 0
+	data[0xfe] = 3    // Status and Read. No write, no format. Single volume
+	data[0xff] = 0x80 // Driver entry point
+
+	return data
+}
+
+const (
+	proDosDeviceCommandStatus = 0
+	proDosDeviceCommandRead   = 1
+	proDosDeviceCommandWrite  = 2
+	proDosDeviceCommandFormat = 3
+)
+
+const (
+	proDosDeviceNoError             = 0
+	proDosDeviceErrorIO             = 0x27
+	proDosDeviceErrorNoDevice       = 0x28
+	proDosDeviceErrorWriteProtected = 0x2b
+)
+
+func (c *cardHardDisk) assign(a *Apple2, slot int) {
+	c.ssr[0] = func(*ioC0Page) uint8 {
+		// Prodos entry point
+		command := a.mmu.Peek(0x42)
+		//unit := a.mmu.Peek(0x43)
+		dest := uint16(a.mmu.Peek(0x44)) + uint16(a.mmu.Peek(0x45))<<8
+		block := uint16(a.mmu.Peek(0x46)) + uint16(a.mmu.Peek(0x47))<<8
+		//fmt.Printf("[CardHardDisk] Command %v on unit $%x, block %v to $%x.\n", command, unit, block, dest)
+
+		switch command {
+		case proDosDeviceCommandStatus:
+			return proDosDeviceNoError
+		case proDosDeviceCommandRead:
+			c.readBlock(block, dest)
+			return proDosDeviceNoError
+		default:
+			panic("Prodos device command not supported.")
+		}
+	}
+	c.ssr[1] = func(*ioC0Page) uint8 {
+		// Blocks available, low byte
+		return uint8(c.disk.header.Blocks)
+	}
+	c.ssr[2] = func(*ioC0Page) uint8 {
+		// Blocks available, high byte
+		return uint8(c.disk.header.Blocks >> 8)
+	}
+
+	c.cardBase.assign(a, slot)
+}
+
+func (c *cardHardDisk) readBlock(block uint16, dest uint16) {
+	//fmt.Printf("[CardHardDisk] Read block %v into $%x.\n", block, dest)
+
+	data := c.disk.read(uint32(block))
+	// Byte by byte transfer to memory using the full Poke code path
+	for i := uint16(0); i < uint16(proDosBlockSize); i++ {
+		c.a.mmu.Poke(dest+i, data[i])
+	}
+
+}
+
+func (c *cardHardDisk) addDisk(disk *hardDisk) {
+	c.disk = disk
+}

cardHardDisk.txt

@@ -1,5 +0,0 @@
-To implement a hard drive we just have to support boot from #PR7 and the PRODOS expextations.
-
-The prodos expectations are in http://wiki.apple2.org/index.php?title=P8_Tech_Ref_Chapter_6#Disk_Driver_Routines
-
-AppleWin writes its own firmware: https://github.com/AppleWin/AppleWin/blob/master/firmware/HDD/hddrvr.a65

hardDisk.go

@@ -0,0 +1,84 @@
+package apple2
+
+import (
+	"bytes"
+	"encoding/binary"
+)
+
+/*
+Valid for ProDos hard disks in 2MG format. Read only.
+
+See:
+	https://apple2.org.za/gswv/a2zine/Docs/DiskImage_2MG_Info.txt
+*/
+
+const (
+	proDosBlockSize         = uint32(512)
+	hardDisk2mgPreamble     = uint32(1196247346) // "2IMG"
+	hardDisk2mgFormatProdos = 1
+	hardDisk2mgVersion      = 1
+)
+
+type hardDisk struct {
+	data   []uint8
+	header hardDisk2mgHeader
+}
+
+type hardDisk2mgHeader struct {
+	Preamble      uint32
+	Creator       uint32
+	HeaderSize    uint16
+	Version       uint16
+	Format        uint32
+	Flags         uint32
+	Blocks        uint32
+	OffsetData    uint32
+	LengthData    uint32
+	OffsetComment uint32
+	LengthComment uint32
+	OffsetCreator uint32
+	LengthCreator uint32
+}
+
+func (hd *hardDisk) read(block uint32) []uint8 {
+	if block >= hd.header.Blocks {
+		return nil
+	}
+	offset := hd.header.OffsetData + block*proDosBlockSize
+	return hd.data[offset : offset+proDosBlockSize]
+}
+
+func loadHardDisk2mg(filename string) *hardDisk {
+	var hd hardDisk
+
+	hd.data = loadResource(filename)
+
+	size := len(hd.data)
+	if size < binary.Size(&hd.header) {
+		panic("2mg file is too short")
+	}
+
+	buf := bytes.NewReader(hd.data)
+	err := binary.Read(buf, binary.LittleEndian, &hd.header)
+	if err != nil {
+		panic(err)
+	}
+
+	if hd.header.Preamble != hardDisk2mgPreamble {
+		panic("2mg file must start with '2IMG'")
+	}
+
+	if hd.header.Format != hardDisk2mgFormatProdos {
+		panic("Only prodos hard disks are supported")
+	}
+
+	if hd.header.Version != hardDisk2mgVersion {
+		panic("Version of 2MG image not supported")
+	}
+
+	if size < int(hd.header.OffsetData+hd.header.Blocks*proDosBlockSize) {
+		panic("Thr 2MG file is too small")
+	}
+
+	return &hd
+}