F6 to toggle mono/color modes

apple2/apple2.go

@@ -20,6 +20,7 @@ type Apple2 struct {
 	activeSlot      int // Slot that has the addressing 0xc800 to 0ccfff
 	commandChannel  chan int
 	cycleDurationNs float64 // Inverse of the cpu clock in Ghz
+	isColor         bool
 }
 
 const (
@@ -29,7 +30,7 @@ const (
 )
 
 // NewApple2 instantiates an apple2
-func NewApple2(romFile string, charRomFile string, clockMhz float64, panicSS bool) *Apple2 {
+func NewApple2(romFile string, charRomFile string, clockMhz float64, isColor bool, panicSS bool) *Apple2 {
 	var a Apple2
 	a.mmu = newMemoryManager(&a)
 	a.cpu = core6502.NewNMOS6502(a.mmu)
@@ -39,6 +40,7 @@ func NewApple2(romFile string, charRomFile string, clockMhz float64, panicSS boo
 	}
 	a.mmu.resetRomPaging()
 	a.commandChannel = make(chan int, 100)
+	a.isColor = isColor
 	a.panicSS = panicSS
 
 	if clockMhz <= 0 {
@@ -91,6 +93,8 @@ func (a *Apple2) SetKeyboardProvider(kb KeyboardProvider) {
 const (
 	// CommandToggleSpeed toggles cpu speed between full speed and actual Apple II speed
 	CommandToggleSpeed = iota + 1
+	// CommandToggleColor toggles between NTSC color TV and Green phospor monitor
+	CommandToggleColor
 )
 
 // SendCommand enqueues a command to the emulator thread
@@ -108,6 +112,8 @@ func (a *Apple2) executeCommand(command int) {
 			fmt.Println("Fast")
 			a.cycleDurationNs = 0
 		}
+	case CommandToggleColor:
+		a.isColor = !a.isColor
 	}
 }
 

apple2/screen.go

@@ -17,6 +17,7 @@ References:
 
 // Snapshot the currently visible screen
 func Snapshot(a *Apple2) *image.RGBA {
+	isColor := a.isColor
 	isTextMode := a.io.isSoftSwitchActive(ioFlagText)
 	isHiResMode := a.io.isSoftSwitchActive(ioFlagHiRes)
 	isMixMode := a.io.isSoftSwitchActive(ioFlagMixed)
@@ -26,32 +27,36 @@ func Snapshot(a *Apple2) *image.RGBA {
 		pageIndex = 1
 	}
 
+	var lightColor color.Color
+	if isColor {
+		lightColor = color.White
+	} else {
+		// Color for typical Apple ][ period green P1 phosphor monitors
+		// See: https://superuser.com/questions/361297/what-colour-is-the-dark-green-on-old-fashioned-green-screen-computer-displays
+		lightColor = color.RGBA{65, 255, 0, 255}
+
+	}
+
 	var snap *image.RGBA
 	if isTextMode {
-		// Color for typical Apple ][ period green phosphor monitors
+		snap = snapshotTextMode(a, pageIndex, false, lightColor)
-		// See: https://superuser.com/questions/361297/what-colour-is-the-dark-green-on-old-fashioned-green-screen-computer-displays
-		p1GreenPhosphorColor := color.RGBA{65, 255, 0, 255}
-
-		snap = snapshotTextMode(a, pageIndex, false, p1GreenPhosphorColor)
-		snap = linesSeparatedFilter(snap)
 	} else {
 		if isHiResMode {
-			//snap = snapshotHiResModeReferenceMono(a, pageIndex, isMixMode)
+			snap = snapshotHiResModeMonoShift(a, pageIndex, isMixMode, lightColor)
-			//snap = snapshotHiResModeReferenceColor(a, pageIndex, isMixMode)
-			//snap = snapshotHiResModeReferenceColorSolid(a, pageIndex, isMixMode)
-			snap = snapshotHiResModeMonoShift(a, pageIndex, isMixMode)
 		} else {
 			// Lo res mode not supported
 			return nil
 		}
 		if isMixMode {
-			snapText := snapshotTextMode(a, pageIndex, isHiResMode, color.White)
+			snapText := snapshotTextMode(a, pageIndex, isHiResMode, lightColor)
 			snap = mixSnapshots(snap, snapText)
 		}
-		//snap = filterNTSCColorStatic(snap)
+		if isColor {
-		snap = filterNTSCColorMoving(false /*blacker*/, snap)
+			snap = filterNTSCColor(false /*blacker*/, snap)
-		snap = linesSeparatedFilter(snap)
+		}
 	}
+
+	snap = linesSeparatedFilter(snap)
 	return snap
 }
 

apple2/screenHgr.go

@@ -37,37 +37,7 @@ func getGraphLine(a *Apple2, line int, page int) []uint8 {
 	return memPage[lo : lo+40]
 }
 
-func snapshotHiResModeReferenceMono(a *Apple2, page int, mixedMode bool) *image.RGBA {
+func snapshotHiResModeMonoShift(a *Apple2, page int, mixedMode bool, light color.Color) *image.RGBA {
-	// As defined on "Apple II Reference Manual", page 19
-
-	height := graphHeight
-	if mixedMode {
-		height = graphHeightMixed
-	}
-
-	size := image.Rect(0, 0, graphWidth, height)
-	img := image.NewRGBA(size)
-
-	for y := 0; y < height; y++ {
-		bytes := getGraphLine(a, y, page)
-		x := 0
-		for _, b := range bytes {
-			for j := uint(0); j < 7; j++ {
-				bit := (b >> j) & 1
-				colour := color.Black
-				if bit == 1 {
-					colour = color.White
-				}
-				img.Set(x, y, colour)
-				x++
-			}
-		}
-	}
-
-	return img
-}
-
-func snapshotHiResModeMonoShift(a *Apple2, page int, mixedMode bool) *image.RGBA {
 	// As described in "Undertanding the Apple II", with half pixel shifts
 
 	height := graphHeight
@@ -81,14 +51,14 @@ func snapshotHiResModeMonoShift(a *Apple2, page int, mixedMode bool) *image.RGBA
 	for y := 0; y < height; y++ {
 		bytes := getGraphLine(a, y, page)
 		x := 0
-		previousColour := color.Black
+		var previousColour color.Color = color.Black
 		for _, b := range bytes {
 			shifted := b>>7 == 1
 			for j := uint(0); j < 7; j++ {
 				bit := (b >> j) & 1
-				colour := color.Black
+				colour := light
-				if bit == 1 {
+				if bit == 0 {
-					colour = color.White
+					colour = color.Black
 				}
 
 				if shifted {

apple2/screenNtscFilter.go

@@ -53,31 +53,7 @@ func getNTSCColorMap() []color.Color {
 	return colorMap
 }
 
-func filterNTSCColorStatic(in *image.RGBA) *image.RGBA {
+func filterNTSCColor(blacker bool, in *image.RGBA) *image.RGBA {
-	colorMap := getNTSCColorMap()
-
-	b := in.Bounds()
-	size := image.Rect(0, 0, b.Dx()/4, b.Dy())
-	out := image.NewRGBA(size)
-	for y := b.Min.Y; y < b.Max.Y; y++ {
-		for x := b.Min.X; x < b.Max.X; x += 4 {
-			v := 0
-			for i := 0; i < 4; i++ {
-				cIn := in.At(x+i, y)
-				r, _, _, _ := cIn.RGBA()
-				v = v << 1
-				if r != 0 {
-					v++
-				}
-			}
-			cOut := colorMap[v]
-			out.Set(x/4, y, cOut)
-		}
-	}
-	return out
-}
-
-func filterNTSCColorMoving(blacker bool, in *image.RGBA) *image.RGBA {
 	colorMap := getNTSCColorMap()
 
 	b := in.Bounds()

apple2sdl/sdlKeyboard.go

@@ -91,6 +91,8 @@ func (k *sdlKeyboard) putKey(keyEvent *sdl.KeyboardEvent) {
 	// Control of the emulator
 	case sdl.K_F5:
 		k.a.SendCommand(apple2.CommandToggleSpeed)
+	case sdl.K_F6:
+		k.a.SendCommand(apple2.CommandToggleColor)
 	}
 
 	// Missing values 91 to 95. Usually control for [\]^_

main.go

@@ -22,7 +22,7 @@ func main() {
 	cpuClock := flag.Float64(
 		"mhz",
 		apple2.CpuClockMhz,
-		"cpu speed in Mhz, use 0 for full speed")
+		"cpu speed in Mhz, use 0 for full speed. Use F5 to toggle.")
 	charRomFile := flag.String(
 		"charRom",
 		"apple2/romdumps/Apple2rev7CharGen.rom",
@@ -35,6 +35,11 @@ func main() {
 		"stdout",
 		false,
 		"show the text screen on the standard output")
+	mono := flag.Bool(
+		"mono",
+		false,
+		"emulate a green phosphor monitor instead of a NTSC color TV. Use F6 to toggle.",
+	)
 	panicSS := flag.Bool(
 		"panicss",
 		false,
@@ -53,7 +58,7 @@ func main() {
 	}
 
 	log := false
-	a := apple2.NewApple2(*romFile, *charRomFile, *cpuClock, *panicSS)
+	a := apple2.NewApple2(*romFile, *charRomFile, *cpuClock, !*mono, *panicSS)
 	a.AddDisk2(*disk2RomFile, *diskImage)
 	if *useSdl {
 		a.ConfigureStdConsole(false, *stdoutScreen)