Support for text mode rendering

apple2/ansiConsoleFrontend.go

@@ -89,7 +89,7 @@ func ansiCursorUp(steps int) {
 	fmt.Printf("\033[%vA", steps)
 }
 
-func (fe *ansiConsoleFrontend) textModeGoRoutine() {
+func (fe *ansiConsoleFrontend) textModeGoRoutineFast() {
 	fe.extraLineFeeds = make(chan int, 100)
 
 	fmt.Printf(strings.Repeat("\n", 26))
@@ -112,7 +112,7 @@ func (fe *ansiConsoleFrontend) textModeGoRoutine() {
 
 			// See "Understand the Apple II", page 5-10
 			// http://www.applelogic.org/files/UNDERSTANDINGTHEAII.pdf
-			isAltText := fe.apple2.isApple2e && fe.apple2.io.isSoftSwitchExtActive(ioFlagAltChar)
+			isAltText := fe.apple2.isApple2e && fe.apple2.io.isSoftSwitchActive(ioFlagAltChar)
 			var i, j, h, c uint8
 			// Top, middle and botton screen
 			for i = 0; i < 120; i = i + 40 {
@@ -139,6 +139,52 @@ func (fe *ansiConsoleFrontend) textModeGoRoutine() {
 	}
 }
 
+func (fe *ansiConsoleFrontend) textModeGoRoutine() {
+	fe.extraLineFeeds = make(chan int, 100)
+
+	fmt.Printf(strings.Repeat("\n", 26))
+	for {
+		if fe.textUpdated {
+			fe.textUpdated = false
+			// Go up
+			ansiCursorUp(26)
+			done := false
+			for !done {
+				select {
+				case lineFeeds := <-fe.extraLineFeeds:
+					ansiCursorUp(lineFeeds)
+				default:
+					done = true
+				}
+			}
+
+			pageIndex := 0
+			if fe.apple2.io.isSoftSwitchActive(ioFlagSecondPage) {
+				pageIndex = 1
+			}
+			isAltText := fe.apple2.isApple2e && fe.apple2.io.isSoftSwitchActive(ioFlagAltChar)
+
+			fmt.Println(strings.Repeat("#", 44))
+			for line := 0; line < 24; line++ {
+				text := ""
+				for col := 0; col < 40; col++ {
+					value := getTextChar(fe.apple2, col, line, pageIndex)
+					text += textMemoryByteToString(value, isAltText)
+				}
+				fmt.Printf("# %v #\n", text)
+			}
+
+			fmt.Println(strings.Repeat("#", 44))
+			if fe.stdinKeyboard {
+				fmt.Print("\033[KLine: ")
+			}
+
+			saveSnapshot(fe.apple2)
+		}
+		time.Sleep(refreshDelayMs * time.Millisecond)
+	}
+}
+
 func textMemoryByteToString(value uint8, isAltCharSet bool) string {
 	// See https://en.wikipedia.org/wiki/Apple_II_character_set
 	// Supports the new lowercase characters in the Apple2e

apple2/apple2.go

@@ -11,6 +11,7 @@ type Apple2 struct {
 	cpu        *core6502.State
 	mmu        *memoryManager
 	io         *ioC0Page
+	cg         *CharacterGenerator
 	cards      []cardBase
 	isApple2e  bool
 	panicSS    bool
@@ -18,11 +19,14 @@ type Apple2 struct {
 }
 
 // NewApple2 instantiates an apple2
-func NewApple2(romFile string, panicSS bool) *Apple2 {
+func NewApple2(romFile string, charRomFile string, panicSS bool) *Apple2 {
 	var a Apple2
 	a.mmu = newMemoryManager(&a)
 	a.cpu = core6502.NewNMOS6502(a.mmu)
 	a.loadRom(romFile)
+	if charRomFile != "" {
+		a.cg = NewCharacterGenerator(charRomFile)
+	}
 	a.mmu.resetPaging()
 	a.panicSS = panicSS
 

apple2/characterGenerator.go

@@ -48,7 +48,13 @@ func (cg *CharacterGenerator) load(filename string) {
 	buf.Read(cg.data)
 }
 
-func (cg *CharacterGenerator) dumpChar(char uint8) {
+func (cg *CharacterGenerator) getPixel(char uint8, row int, column int) bool {
+	bits := cg.data[int(char)*8+row]
+	bit := bits >> (uint(6 - column)) & 1
+	return bit == 1
+}
+
+func (cg *CharacterGenerator) dumpCharFast(char uint8) {
 	base := int(char) * 8
 	fmt.Printf("Char: %v\n---------\n", char)
 	for i := 0; i < 8; i++ {
@@ -66,6 +72,23 @@ func (cg *CharacterGenerator) dumpChar(char uint8) {
 	fmt.Println("---------")
 }
 
+func (cg *CharacterGenerator) dumpChar(char uint8) {
+	fmt.Printf("Char: %v\n---------\n", char)
+	for row := 0; row < 8; row++ {
+		fmt.Print("|")
+		for col := 0; col < 7; col++ {
+			if cg.getPixel(char, row, col) {
+				fmt.Print("#")
+			} else {
+				fmt.Print(" ")
+			}
+		}
+		fmt.Println("|")
+	}
+	fmt.Println("---------")
+}
+
+// Dump to sdtout all the character maps
 func (cg *CharacterGenerator) Dump() {
 	for i := 0; i < 256; i++ {
 		cg.dumpChar(uint8(i))

apple2/ioC0Page.go

@@ -15,7 +15,7 @@ type ioC0Page struct {
 type softSwitchR func(io *ioC0Page) uint8
 type softSwitchW func(io *ioC0Page, value uint8)
 
-// KeyboardProvider declares the keyboard implementation requitements
+// KeyboardProvider declares the keyboard implementation requirements
 type KeyboardProvider interface {
 	GetKey(strobe bool) (key uint8, ok bool)
 }
@@ -61,7 +61,7 @@ func (p *ioC0Page) addSoftSwitchW(address uint8, ss softSwitchW) {
 	p.softSwitchesW[address] = ss
 }
 
-func (p *ioC0Page) isSoftSwitchExtActive(ioFlag uint8) bool {
+func (p *ioC0Page) isSoftSwitchActive(ioFlag uint8) bool {
 	return (p.softSwitchesData[ioFlag] & ssOn) == ssOn
 }
 
@@ -81,6 +81,10 @@ func (p *ioC0Page) Peek(address uint8) uint8 {
 	return ss(p)
 }
 
+func (p *ioC0Page) internalPeek(address uint8) uint8 {
+	return 0
+}
+
 func (p *ioC0Page) Poke(address uint8, value uint8) {
 	//fmt.Printf("Poke on $C0%02x with %02x ", address, value)
 	ss := p.softSwitchesW[address]

apple2/memoryManager.go

@@ -19,6 +19,7 @@ type memoryManager struct {
 type memoryPage interface {
 	Peek(uint8) uint8
 	Poke(uint8, uint8)
+	internalPeek(uint8) uint8
 }
 
 const (
@@ -36,6 +37,12 @@ func (mmu *memoryManager) Peek(address uint16) uint8 {
 	return mmu.activeMemory[hi].Peek(lo)
 }
 
+func (mmu *memoryManager) internalPeek(address uint16) uint8 {
+	hi := uint8(address >> 8)
+	lo := uint8(address)
+	return mmu.activeMemory[hi].internalPeek(lo)
+}
+
 // Poke sets the data at the given address
 func (mmu *memoryManager) Poke(address uint16, value uint8) {
 	if address == ioC8Off {
@@ -55,7 +62,7 @@ func (mmu *memoryManager) setPage(index uint8, page memoryPage) {
 
 // When 0xcfff is accessed the card expansion rom is unassigned
 func (mmu *memoryManager) resetSlotExpansionRoms() {
-	if mmu.apple2.io.isSoftSwitchExtActive(ioFlagIntCxRom) {
+	if mmu.apple2.io.isSoftSwitchActive(ioFlagIntCxRom) {
 		// Ignore if the Apple2 shadow ROM is active
 		return
 	}

apple2/screen.go

@@ -0,0 +1,94 @@
+package apple2
+
+import (
+	"fmt"
+	"image"
+	"image/color"
+	"image/png"
+	"os"
+)
+
+func snapshot(a *Apple2) image.Image {
+	isTextMode := a.io.isSoftSwitchActive(ioFlagGraphics)
+	is80ColMode := a.io.isSoftSwitchActive(ioFlag80Col)
+	pageIndex := 0
+	if a.io.isSoftSwitchActive(ioFlagSecondPage) {
+		pageIndex = 1
+	}
+
+	if isTextMode && !is80ColMode {
+		//Text mode
+		return snapshotTextMode(a, pageIndex)
+	}
+	fmt.Printf("t: %v, 8: %v\n", isTextMode, is80ColMode)
+	return nil
+	//panic("Screen mode not supported")
+}
+
+func saveSnapshot(a *Apple2) {
+	img := snapshot(a)
+	if img == nil {
+		return
+	}
+
+	f, err := os.Create("snapshot.png")
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+
+	fmt.Println("Saving snapshot")
+
+	png.Encode(f, img)
+}
+
+const (
+	charWidth        = 7
+	charHeight       = 8
+	textColumns      = 40
+	textLines        = 24
+	textPage1Address = uint16(0x400)
+	textPage2Address = uint16(0x400)
+)
+
+func getTextChar(a *Apple2, col int, line int, page int) uint8 {
+	address := textPage1Address
+	if page == 1 {
+		address = textPage2Address
+	}
+
+	// See "Understand the Apple II", page 5-10
+	// http://www.applelogic.org/files/UNDERSTANDINGTHEAII.pdf
+	section := line / 8 // Top, middle and bottom
+	eigth := line % 8
+	address += uint16(section*40 + eigth*0x80 + col)
+	return a.mmu.internalPeek(address)
+}
+
+func snapshotTextMode(a *Apple2, page int) image.Image {
+	width := textColumns * charWidth
+	height := textLines * charHeight
+	size := image.Rect(0, 0, width, height)
+	bwPalette := []color.Color{color.Black, color.White}
+	img := image.NewPaletted(size, bwPalette)
+
+	for x := 0; x < width; x++ {
+		for y := 0; y < height; y++ {
+			//yRev := height - y
+			line := y / charHeight
+			col := x / charWidth
+			rowInChar := y % charHeight
+			colInChar := x % charWidth
+			char := getTextChar(a, col, line, page)
+			pixel := a.cg.getPixel(char, rowInChar, colInChar)
+			color := uint8(0)
+			if pixel {
+				color = 1
+			}
+			img.SetColorIndex(x, y, color)
+		}
+
+	}
+
+	return img
+}

apple2/softSwitches2e.go

@@ -60,7 +60,7 @@ func softSwitchIntCxRomOff(io *ioC0Page) {
 }
 
 func softSwitchSlotC3RomOn(io *ioC0Page) {
-	if io.isSoftSwitchExtActive(ioFlagIntCxRom) {
+	if io.isSoftSwitchActive(ioFlagIntCxRom) {
 		return // Ignore if allt the Apple2 shadow ROM is active
 	}
 	// TODO restore the slot 3 ROM
@@ -69,7 +69,7 @@ func softSwitchSlotC3RomOn(io *ioC0Page) {
 }
 
 func softSwitchSlotC3RomOff(io *ioC0Page) {
-	if io.isSoftSwitchExtActive(ioFlagIntCxRom) {
+	if io.isSoftSwitchActive(ioFlagIntCxRom) {
 		return // Ignore if allt the Apple2 shadow ROM is active
 	}
 	mmu := io.apple2.mmu

apple2/unassignedPage.go

@@ -10,6 +10,10 @@ func (p *unassignedPage) Peek(address uint8) uint8 {
 	return 0xdd
 }
 
+func (p *unassignedPage) internalPeek(address uint8) uint8 {
+	return 0xdd
+}
+
 func (p *unassignedPage) Poke(address uint8, value uint8) {
 	//fmt.Printf("Write on address 0x%02x%02x\n", p.page, address)
 	//panic(address)

main.go

@@ -53,7 +53,7 @@ func main() {
 	}
 
 	log := false
-	a := apple2.NewApple2(*romFile, *panicSS)
+	a := apple2.NewApple2(*romFile, *charRomFile, *panicSS)
 	a.AddDisk2(*disk2RomFile, *diskImage)
 	if *useSdl {
 		apple2sdl.SDLRun(a)