ROMXe font emulation

README.md

@@ -33,6 +33,7 @@ Portable emulator of an Apple II+ or //e. Written in Go.
   - FASTChip, limited to what Total Replay needs to set and clear fast mode
   - Mouse Card, emulates the entry points, not the softswitches.
   - Host console card. Maps the host STDIN and STDOUT to PR# and IN#
+  - ROMXe, limited to font switching
 
 - Graphic modes:
   - Text 40 columns
@@ -223,6 +224,8 @@ Only valid on SDL mode
         emulate the RGB modes of the 80col RGB card for DHGR (default true)
   -rom string
         main rom file (default "<default>")
+  -romx
+        emulate a RomX
   -saturnCardSlot int
         slot for the 256kb Saturn card. -1 for none (default -1)
   -sequencer

apple2Setup.go

@@ -209,9 +209,13 @@ func (a *Apple2) AddNoSlotClock() {
 }
 
 // AddRomX inserts a RomX. It intercepts all memory accesses
-func (a *Apple2) AddRomX() {
+func (a *Apple2) AddRomX() error {
-	rx := newRomX(a, a.mmu)
+	rx, err := newRomX(a, a.mmu)
+	if err != nil {
+		return err
+	}
 	a.cpu.SetMemory(rx)
+	return nil
 }
 
 // AddNoSlotClockInCard inserts a DS1215 no slot clock under a card ROM

apple2main.go

@@ -94,6 +94,10 @@ func MainApple() *Apple2 {
 		"rgb",
 		true,
 		"emulate the RGB modes of the 80col RGB card for DHGR")
+	romX := flag.Bool(
+		"romx",
+		false,
+		"emulate a RomX")
 	fastDisk := flag.Bool(
 		"fastDisk",
 		true,
@@ -258,7 +262,7 @@ func MainApple() *Apple2 {
 	}
 
 	// Load character generator if it loaded already
-	cg, err := newCharacterGenerator(*charRomFile, charGenMap)
+	cg, err := newCharacterGenerator(*charRomFile, charGenMap, a.isApple2e)
 	if err != nil {
 		panic(err)
 	}
@@ -347,7 +351,13 @@ func MainApple() *Apple2 {
 
 	}
 
-	// a.AddRomX()
+	if *romX {
+		err := a.AddRomX()
+		if err != nil {
+			panic(err)
+		}
+	}
+
 	// a.AddCardLogger(4)
 
 	return a

characterGenerator.go

@@ -16,6 +16,7 @@ type CharacterGenerator struct {
 	data      []uint8
 	columnMap charColumnMap
 	page      int
+	pageSize  int
 }
 
 type charColumnMap func(column int) int
@@ -29,17 +30,24 @@ func charGenColumnsMap2e(column int) int {
 }
 
 const (
-	charGenPageSize = 2048
+	charGenPageSize2Plus = 2048
+	charGenPageSize2E    = 2048 * 2
 )
 
 // NewCharacterGenerator instantiates a new Character Generator with the rom on the file given
-func newCharacterGenerator(filename string, order charColumnMap) (*CharacterGenerator, error) {
+func newCharacterGenerator(filename string, order charColumnMap, isApple2e bool) (*CharacterGenerator, error) {
 	var cg CharacterGenerator
+	cg.columnMap = order
+	cg.pageSize = charGenPageSize2Plus
+	if isApple2e {
+		cg.pageSize = charGenPageSize2E
+	}
+
 	err := cg.load(filename)
 	if err != nil {
 		return nil, err
 	}
-	cg.columnMap = order
+
 	return &cg, nil
 }
 
@@ -49,7 +57,7 @@ func (cg *CharacterGenerator) load(filename string) error {
 		return err
 	}
 	size := len(bytes)
-	if size < charGenPageSize {
+	if size < cg.pageSize {
 		return errors.New("character ROM size not supported")
 	}
 	cg.data = bytes
@@ -58,16 +66,20 @@ func (cg *CharacterGenerator) load(filename string) error {
 
 func (cg *CharacterGenerator) setPage(page int) {
 	// Some clones had a switch to change codepage with extra characters
-	pages := len(cg.data) / charGenPageSize
+	pages := len(cg.data) / cg.pageSize
 	cg.page = page % pages
 }
 
+func (cg *CharacterGenerator) getPage() int {
+	return cg.page
+}
+
 func (cg *CharacterGenerator) nextPage() {
 	cg.setPage(cg.page + 1)
 }
 
 func (cg *CharacterGenerator) getPixel(char uint8, row int, column int) bool {
-	bits := cg.data[int(char)*8+row+cg.page*charGenPageSize]
+	bits := cg.data[int(char)*8+row+cg.page*cg.pageSize]
 	bit := cg.columnMap(column)
 	value := bits >> uint(bit) & 1
 	return value == 1

romX.go

@@ -10,10 +10,14 @@ import (
 RomX from https://theromexchange.com/
 This complement uses the RomX API spec to switch main ROM and character generator ROM
 
+Only the font switch is implemented
+
 See:
 	https://theromexchange.com/documentation/ROM%20X%20API%20Reference.pdf
 	https://theromexchange.com/downloads/ROM%20X%2020-10-22.zip
+	https://theromexchange.com/documentation/romxce/ROMXce%20API%20Reference.pdf
 
+For romX:
 It is not enough to intercept the ROM accesses. RomX intercept the 74LS138 in
 position F12, that has access to the full 0xc000-0xf000 on the Apple II+
 
@@ -30,32 +34,64 @@ type romX struct {
 	memory         core6502.Memory
 	activationStep int
 	systemBank     uint8
+	mainBank       uint8
+	tempBank       uint8
 	textBank       uint8
+	debug          bool
 }
 
 var romXActivationSequence = []uint16{0xcaca, 0xcaca, 0xcafe}
+var romXceActivationSequence = []uint16{0xfaca, 0xfaca, 0xfafe}
 
 const (
-	setupBank                    = uint8(0)
+	romxSetupBank                    = uint8(0)
-	romXSetSystemBankBaseAddress = uint16(0xcef0)
+	romXPlusSetSystemBankBaseAddress = uint16(0xcef0)
-	romXSetTextBankBaseAddress   = uint16(0xcfd0)
+	romXPlusSetTextBankBaseAddress   = uint16(0xcfd0)
-	romXDefaultSystemBankAddress = uint16(0xd034)
-	romXDefaultTextBankAddress   = uint16(0xd02e)
 
 	// Unknown
-	romXFirmwareMark0Address = uint16(0xdffe)
+	//romXFirmwareMark0Address = uint16(0xdffe)
-	romXFirmwareMark0Value   = uint8(0x4a)
+	//romXFirmwareMark0Value   = uint8(0x4a)
-	romXFirmwareMark1Address = uint16(0xdfff)
+	//romXFirmwareMark1Address = uint16(0xdfff)
-	romXFirmwareMark1Value   = uint8(0xcd)
+	//romXFirmwareMark1Value   = uint8(0xcd)
+
+	romXceSelectTempBank  = uint16(0xf850)
+	romXceSelectMainBank  = uint16(0xf851)
+	romXceSetTempBank     = uint16(0xf830) // 16 positions
+	romXceSetMainBank     = uint16(0xf800) // 16 positions
+	romXcePresetTextBank  = uint16(0xf810) // 16 positions
+	romXceMCP7940SDC      = uint16(0xf860) // 16 positions
+	romXceLowerUpperBanks = uint16(0xf820) // 16 positions
+
+	romXGetDefaultSystemBank = uint16(0xd034) // $00 to $0f
+	romXGetDefaultTextBank   = uint16(0xd02e) // $10 to $1f
+	romXGetCurrentBootDelay  = uint16(0xdeca) // $00 to $0f
+
+	/*
+		romXceEntryPointSetClock      = uint16(0xc803)
+		romXceEntryPointReadClock     = uint16(0xc803)
+		romXceEntryPointLauncherToRam = uint16(0xdfd9)
+		romXceEntryPointLauncher      = uint16(0xdfd0)
+	*/
 )
 
-func newRomX(a *Apple2, memory core6502.Memory) *romX {
+func newRomX(a *Apple2, memory core6502.Memory) (*romX, error) {
 	var rx romX
 	rx.a = a
 	rx.memory = memory
-	rx.systemBank = 0
+	rx.systemBank = 1
+	rx.mainBank = 1
+	rx.tempBank = 1
 	rx.textBank = 0
-	return &rx
+	rx.debug = true
+
+	if a.isApple2e {
+		err := a.cg.load("<internal>/ROMXce Production 1Mb Text ROM V5.bin")
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &rx, nil
 }
 
 func (rx *romX) Peek(address uint16) uint8 {
@@ -67,10 +103,10 @@ func (rx *romX) Peek(address uint16) uint8 {
 }
 
 func (rx *romX) PeekCode(address uint16) uint8 {
-	//intercepted, value := rx.interceptAccess(address)
+	intercepted, value := rx.interceptAccess(address)
-	//if intercepted {
+	if intercepted {
-	//	return value
+		return value
-	//}
+	}
 	return rx.memory.PeekCode(address)
 }
 
@@ -79,6 +115,11 @@ func (rx *romX) Poke(address uint16, value uint8) {
 	rx.memory.Poke(address, value)
 }
 
+func (rx *romX) logf(format string, a ...interface{}) {
+	msg := fmt.Sprintf(format, a...)
+	fmt.Printf("[romX]%s\n", msg)
+}
+
 func (rx *romX) interceptAccess(address uint16) (bool, uint8) {
 	// Intercept only $C080 to $FFFF as seen by the F12 chip
 	if address < 0xc080 {
@@ -86,45 +127,65 @@ func (rx *romX) interceptAccess(address uint16) (bool, uint8) {
 	}
 
 	// Setup mode when the setup bank is active
-	if rx.systemBank == setupBank {
+	if rx.systemBank == romxSetupBank {
-		switch address {
+
-		case romXDefaultSystemBankAddress:
+		// Range commands
-			fmt.Printf("[romX]Peek in $%04x, current system bank %v\n", address, rx.systemBank)
+		nibble := uint8(address & 0xf)
-			return true, 0xe0 + rx.systemBank
+		switch address & 0xfff0 {
-		case romXDefaultTextBankAddress:
+		case romXceSetMainBank:
-			fmt.Printf("[romX]PeeK in $%04x, current text bank %v\n", address, rx.textBank)
+			rx.mainBank = nibble
-			return true, 0xd0 + rx.textBank
+			rx.logf("Main bank set to $%x", nibble)
-		case romXFirmwareMark0Address:
+		case romXcePresetTextBank:
-			fmt.Printf("[romX]Peek in $%04x, ???\n", address)
+			textBank := int(nibble)
-			return true, romXFirmwareMark0Value
+			rx.a.cg.setPage(textBank)
-		case romXFirmwareMark1Address:
+			rx.logf("[romX]Text bank set to $%x", nibble)
-			fmt.Printf("[romX]Peek in $%04x, ???\n", address)
+		case romXceLowerUpperBanks:
-			return true, romXFirmwareMark1Value
+			rx.logf("Configure lower upper banks $%x", address)
+		case romXceSetTempBank:
+			rx.tempBank = nibble
+			rx.logf("Temp bank set to $%x", nibble)
+		case romXceMCP7940SDC:
+			rx.logf("Configure MCP7940 $%x", address)
 		}
 
-		if address&0xfff0 == romXSetSystemBankBaseAddress {
+		// More commands
-			rx.systemBank = uint8(address & 0xf)
+		switch address {
-			fmt.Printf("[romX]System bank set to %v\n", rx.systemBank)
+		case romXceSelectTempBank:
-		} else if address&0xfff0 == romXSetTextBankBaseAddress {
+			rx.systemBank = rx.tempBank
-			rx.textBank = uint8(address & 0xf)
+			rx.logf("System bank set to temp bank $%x", rx.systemBank)
-			fmt.Printf("[romX]Text bank set to %v\n", rx.textBank)
+		case romXceSelectMainBank:
-		} else if address < 0xe000 {
+			rx.systemBank = rx.mainBank
-			fmt.Printf("[romX]Peek in $%04x\n", address)
+			rx.logf("System bank set to main bank $%x", rx.systemBank)
+		}
+
+		// Queries
+		switch address {
+		case romXGetDefaultSystemBank:
+			bank := rx.systemBank
+			rx.logf("Peek in $%04x, current system bank %v", address, bank)
+			return true, bank
+		case romXGetDefaultTextBank:
+			page := uint8(rx.a.cg.getPage() & 0xf)
+			rx.logf("PeeK in $%04x, current text bank %v", address, page)
+			return true, 0x10 + page
+		case romXGetCurrentBootDelay:
+			delay := uint8(5) // We don't care
+			rx.logf("PeeK in $%04x, current boot delay %v", address, delay)
+			return true, delay
 		}
 
 		return false, 0
 	}
 
 	// Activation sequence detection
-	if address == romXActivationSequence[rx.activationStep] {
+	if address == romXceActivationSequence[rx.activationStep] {
 		rx.activationStep++
-		//fmt.Printf("[romX]Activation step %v\n", rx.activationStep)
+		rx.logf("Activation step %v", rx.activationStep)
 		if rx.activationStep == len(romXActivationSequence) {
 			// Activation sequence completed
-			rx.systemBank = setupBank
+			rx.systemBank = romxSetupBank
 			rx.activationStep = 0
-			//			rx.a.cpu.SetTrace(true)
+			rx.logf("System bank set to 0, %v", rx.systemBank)
-			fmt.Printf("[romX]System bank set to 0, %v\n", rx.systemBank)
 		}
 	} else {
 		rx.activationStep = 0