diff --git a/README.md b/README.md
index ff6a07c..d145452 100644
--- a/README.md
+++ b/README.md
@@ -54,6 +54,12 @@ Portable emulator of an Apple II+ or //e. Written in Go.
   - RGB for Super High Resolution and RGB card
   - ANSI Console, avoiding the SDL2 dependency
   - Debug mode: shows four panels with actual screen, page1, page2 and extra info dependant of the video mode
+- Tracing capabilities:
+  - CPU execution disassembled
+  - Softswitch reads and writes
+  - ProDOS MLI calls
+  - Apple Pascal BIOS calls
+  - Smartport commands
 - Other features:
   - Sound
   - Joystick support. Up to two joysticks or four paddles
@@ -62,7 +68,6 @@ Portable emulator of an Apple II+ or //e. Written in Go.
   - Fast disk mode to set max speed while using the disks
   - Single file executable with embedded ROMs and DOS 3.3
   - Pause (thanks a2geek)
-  - ProDOS MLI calls tracing
   - Passes the [A2AUDIT 1.06](https://github.com/zellyn/a2audit) tests as II+, //e, and //e Enhanced.
 
 By default the following configuration is launched:
@@ -226,6 +231,8 @@ Only valid on SDL mode
         dump to the console the hd/smartport commands
   -traceMLI
         dump to the console the calls to ProDOS machine language interface calls to $BF00
+  -tracePascal
+        dump to the console the calls to the Apple Pascal BIOS
   -traceSS
         dump to the console the sofswitches calls
   -traceSSReg
diff --git a/apple2.go b/apple2.go
index 1b296e4..3acf9cb 100644
--- a/apple2.go
+++ b/apple2.go
@@ -24,10 +24,14 @@ type Apple2 struct {
 	profile             bool
 	showSpeed           bool
 	paused              bool
-	traceMLI            *traceProDOS
+	tracers             []executionTracer
 	forceCaps           bool
 }
 
+type executionTracer interface {
+	inspect()
+}
+
 const (
 	// CPUClockMhz is the actual Apple II clock speed
 	CPUClockMhz     = 14.318 / 14
@@ -211,8 +215,10 @@ func (a *Apple2) releaseFastMode() {
 }
 
 func (a *Apple2) executionTrace() {
-	if a.traceMLI != nil {
-		a.traceMLI.inspect()
+	if a.tracers != nil {
+		for _, v := range a.tracers {
+			v.inspect()
+		}
 	}
 }
 
@@ -223,15 +229,17 @@ func (a *Apple2) dumpDebugInfo() {
 		0x37: "CSWH",
 		0x38: "KSWL",
 		0x39: "KSWH",
+		0xe2: "ACJVAFLDL", // Apple Pascal
+		0xe3: "ACJVAFLDH", // Apple Pascal
+		0xec: "JVBFOLDL",  // Apple Pascal
+		0xed: "JVBFOLDH",  // Apple Pascal
+		0xee: "JVAFOLDL",  // Apple Pascal
+		0xef: "JVAFOLDH",  // Apple Pascal
 	}
 
 	fmt.Printf("Page zero values:\n")
-	for _, k := range []int{0x36, 0x37, 0x38, 0x39} {
+	for _, k := range []int{0x36, 0x37, 0x38, 0x39, 0xe2, 0xe3, 0xec, 0xed, 0xee, 0xef} {
 		d := a.mmu.physicalMainRAM.data[k]
 		fmt.Printf("  %v(0x%x): 0x%02x\n", pageZeroSymbols[k], k, d)
 	}
-
-	if a.traceMLI != nil {
-		a.traceMLI.dumpDevices()
-	}
 }
diff --git a/apple2Setup.go b/apple2Setup.go
index 5540ee6..4575972 100644
--- a/apple2Setup.go
+++ b/apple2Setup.go
@@ -16,12 +16,9 @@ func newApple2() *Apple2 {
 	return &a
 }
 
-func (a *Apple2) setup(clockMhz float64, fastMode bool, traceMLI bool) {
+func (a *Apple2) setup(clockMhz float64, fastMode bool) {
 	a.commandChannel = make(chan int, 100)
 	a.fastMode = fastMode
-	if traceMLI {
-		a.traceMLI = newTraceProDOS(a)
-	}
 
 	if clockMhz <= 0 {
 		// Full speed
@@ -55,6 +52,14 @@ func setApple2eEnhanced(a *Apple2) {
 	addApple2ESoftSwitches(a.io)
 }
 
+func (a *Apple2) addTracer(tracer executionTracer) {
+	if a.tracers == nil {
+		a.tracers = make([]executionTracer, 0)
+	}
+
+	a.tracers = append(a.tracers, tracer)
+}
+
 func (a *Apple2) insertCard(c Card, slot int) {
 	c.assign(a, slot)
 	a.cards[slot] = c
diff --git a/apple2main.go b/apple2main.go
index f988f1d..94ee823 100644
--- a/apple2main.go
+++ b/apple2main.go
@@ -130,6 +130,10 @@ func MainApple() *Apple2 {
 		"traceMLI",
 		false,
 		"dump to the console the calls to ProDOS machine language interface calls to $BF00")
+	tracePascal := flag.Bool(
+		"tracePascal",
+		false,
+		"dump to the console the calls to the Apple Pascal BIOS")
 	forceCaps := flag.Bool(
 		"forceCaps",
 		false,
@@ -150,12 +154,18 @@ func MainApple() *Apple2 {
 	}
 
 	a := newApple2()
-	a.setup(*cpuClock, *fastDisk, *traceMLI)
+	a.setup(*cpuClock, *fastDisk)
 	a.io.setTrace(*traceSS)
 	a.io.setTraceRegistrations(*traceSSReg)
 	a.io.setPanicNotImplemented(*panicSS)
 	a.setProfiling(*profile)
 	a.SetForceCaps(*forceCaps)
+	if *traceMLI {
+		a.addTracer(newTraceProDOS(a))
+	}
+	if *tracePascal {
+		a.addTracer(newTracePascal(a))
+	}
 
 	var charGenMap charColumnMap
 	initialCharGenPage := 0
diff --git a/core6502/registers.go b/core6502/registers.go
index c6e9e26..90d2f7b 100644
--- a/core6502/registers.go
+++ b/core6502/registers.go
@@ -87,7 +87,11 @@ func (r *registers) updateFlagZN(t uint8) {
 }
 
 func (r registers) String() string {
-	ch := (r.getA() & 0x3F) + 0x40
+	//ch := (r.getA() & 0x3F) + 0x40
+	ch := (r.getA() & 0x7F)
+	if ch < 0x20 {
+		ch += 0x40
+	}
 	return fmt.Sprintf("A: %#02x(%v), X: %#02x, Y: %#02x, SP: %#02x, PC: %#04x, P: %#02x, (NV-BDIZC): %08b",
 		r.getA(), string(ch), r.getX(), r.getY(), r.getSP(), r.getPC(), r.getP(), r.getP())
 }
diff --git a/memoryManager.go b/memoryManager.go
index 67daea9..d280e99 100644
--- a/memoryManager.go
+++ b/memoryManager.go
@@ -29,7 +29,7 @@ type memoryManager struct {
 	// Configuration switches, Language cards
 	lcSelectedBlock uint8 // Language card block selected. Usually, allways 0. But Saturn has 8
 	lcActiveRead    bool  // Upper RAM active for read
-	lcActiveWrite   bool  // Upper RAM active for read
+	lcActiveWrite   bool  // Upper RAM active for write
 	lcAltBank       bool  // Alternate
 
 	// Configuration switches, Apple //e
diff --git a/tracePascal.go b/tracePascal.go
new file mode 100644
index 0000000..ecfadfa
--- /dev/null
+++ b/tracePascal.go
@@ -0,0 +1,210 @@
+package izapple2
+
+import "fmt"
+
+type tracePascal struct {
+	a           *Apple2
+	skipConsole bool
+}
+
+const (
+	pascalJvabfoldL uint16 = 0x00ec // Points to the BIOS entry points
+	pascalJvabfoldH uint16 = 0x00ed // Points to the BIOS entry points
+)
+
+func newTracePascal(a *Apple2) *tracePascal {
+	var t tracePascal
+	t.a = a
+	t.skipConsole = true
+	return &t
+}
+
+/*
+  See:
+  	https://archive.org/details/Hyde_P-Source-A_Guide_to_the_APPLE_Pascal_System_1983/page/n415/mode/1up?view=theater
+  	https://archive.org/details/Apple_II_Pascal_1.2_Device_and_Interrupt_Support_Tools_Manual
+
+	Experimental. Not sure the paramters for DREAD and DWRITE are correct.
+*/
+func (t *tracePascal) inspect() {
+	bios := uint16(t.a.mmu.physicalMainRAM.peek(pascalJvabfoldL)) +
+		uint16(t.a.mmu.physicalMainRAM.peek(pascalJvabfoldH))<<8
+	pc, _ := t.a.cpu.GetPCAndSP()
+	if pc >= bios && pc < bios+0x5a {
+		offset := uint8(pc - bios)
+
+		if t.skipConsole && offset <= 0x03 {
+			return
+		}
+
+		_, regA := t.a.cpu.GetCarryAndAcc()
+		regAText := string(regA)
+		if regA < 0x20 {
+			regAText = "^" + string(regA+0x40)
+
+		}
+
+		fmt.Printf("Pascal BIOS call $%02x from $%04x ", offset, t.param(1))
+		switch offset {
+		case 0:
+			fmt.Printf("CREAD()")
+		case 3:
+			fmt.Printf("CWRITE('%s'[%v])", regAText, regA)
+		case 6:
+			fmt.Printf("CINIT(BREAK=[$%04x], SYSCOM=[$%04x])",
+				t.param(3), t.param(5))
+		case 9:
+			fmt.Printf("PWRITE('%s'[%v])", regAText, regA)
+		case 12:
+			fmt.Printf("PINIT()")
+		case 15:
+			fmt.Printf("DWRITE(UNIT=%v, BLOCK=%v, LEN=%v, DATA=[$%04x], DRIVE=%v, CONTROL=$%04x)",
+				regA, t.param(3), t.param(5), t.param(7), t.param(9), t.param(11))
+		case 18:
+			fmt.Printf("DREAD(UNIT=%v, BLOCK=%v, LEN=%v, DATA=[$%04x], DRIVE=%v, CONTROL=$%04x)",
+				regA, t.param(3), t.param(5), t.param(7), t.param(9), t.param(11))
+		case 21:
+			fmt.Printf("DINIT(DRIVE=%v)", regA)
+		case 24:
+			fmt.Printf("RREAD()")
+		case 27:
+			fmt.Printf("RWRITE('%s'[%v])", regAText, regA)
+		case 30:
+			fmt.Printf("RINIT()")
+		case 33:
+			fmt.Printf("GWRITE()")
+		case 36:
+			fmt.Printf("GRINIT()")
+		case 39:
+			fmt.Printf("PREAD()")
+		case 42:
+			fmt.Printf("CSTAT()")
+		case 45:
+			fmt.Printf("PSTAT()")
+		case 48:
+			fmt.Printf("DSTAT()")
+		case 51:
+			fmt.Printf("RSTAT()")
+		case 54:
+			fmt.Printf("CONCK()")
+		case 57:
+			fmt.Printf("UDRWI()")
+		case 60:
+			fmt.Printf("PSUBDRV()")
+
+		default:
+			fmt.Printf("<unknown>")
+		}
+		fmt.Printf("\n")
+	}
+}
+
+/*
+ See http://www.bitsavers.org/pdf/softech/softechPascalIV_intArch1981.pdf
+ page 106
+*/
+func (t *tracePascal) inspectPerArchitectureGuide() {
+	bios := uint16(t.a.mmu.physicalMainRAM.peek(pascalJvabfoldL)) +
+		uint16(t.a.mmu.physicalMainRAM.peek(pascalJvabfoldH))<<8
+	pc, _ := t.a.cpu.GetPCAndSP()
+	if pc >= bios && pc < bios+0x5a {
+		offset := uint8(pc - bios)
+
+		if t.skipConsole && offset <= 0x03 {
+			return
+		}
+
+		_, regA := t.a.cpu.GetCarryAndAcc()
+		regAText := string(regA)
+		if regA < 0x20 {
+			regAText = "^" + string(regA+0x40)
+
+		}
+
+		fmt.Printf("Pascal BIOS call $%02x from $%04x ", offset, t.param(1))
+		switch offset {
+		// Console
+		case 0x00:
+			fmt.Printf("CONSOLEREAD()")
+		case 0x03:
+			fmt.Printf("CONSOLEWRITE('%s'[%v])", regAText, regA)
+		case 0x06:
+			fmt.Printf("CONSOLECTRL(BREAK=[%04x], SYSCOM=[%04x])",
+				t.param(3), t.param(5))
+		case 0x09:
+			fmt.Printf("CONSOLESTAT(STATREC=[%04x], CONTROL=%04x)",
+				t.param(3), t.param(5))
+
+		// Printer
+		case 0x0c:
+			fmt.Printf("PRINTERREAD()")
+		case 0x0f:
+			fmt.Printf("PRINTERWRITE('%s'[%v])", regAText, regA)
+		case 0x12:
+			fmt.Printf("PRINTERCTRL()")
+		case 0x15:
+			fmt.Printf("PRINTERSTAT(STATREC=[%04x], CONTROL=%04x)",
+				t.param(3), t.param(5))
+
+		// Disk
+		case 0x18:
+			fmt.Printf("DISKREAD(BLOCK=%04x, LEN=%04x, DATA=[%04x], DRIVE=%v, CONTROL=%04x)",
+				t.param(3), t.param(5), t.param(7), t.param(9), t.param(11))
+		case 0x1b:
+			fmt.Printf("DISKWRITE(BLOCK=%04x, LEN=%04x, DATA=[%04x], DRIVE=%v, CONTROL=%04x)",
+				t.param(3), t.param(5), t.param(7), t.param(9), t.param(11))
+		case 0x1e:
+			fmt.Printf("DISKCTRL(DRIVE=%v)", regA)
+		case 0x21:
+			fmt.Printf("DISKSTAT(DRIVE=%v, STATREC=[%04x], CONTROL=%04x)",
+				regA, t.param(3), t.param(5))
+
+		// Remote
+		case 0x24:
+			fmt.Printf("REMOTEREAD()")
+		case 0x27:
+			fmt.Printf("REMOTEWRITE('%s'[%v])", regAText, regA)
+		case 0x2a:
+			fmt.Printf("REMOTECTRL()")
+		case 0x2d:
+			fmt.Printf("REMOTESTAT(STATREC=[%04x], CONTROL=%04x)",
+				t.param(3), t.param(5))
+
+		// User
+		case 0x30:
+			fmt.Printf("USERREAD(BLOCK=%04x, LEN=%04x, DATA=[%04x], DEVICE=%v, CONTROL=%04x)",
+				t.param(3), t.param(5), t.param(7), t.param(9), t.param(11))
+		case 0x33:
+			fmt.Printf("USERWRITE(BLOCK=%04x, LEN=%04x, DATA=[%04x], DEVICE=%v, CONTROL=%04x)",
+				t.param(3), t.param(5), t.param(7), t.param(9), t.param(11))
+		case 0x36:
+			fmt.Printf("USERCTRL(DEVICE=%v)", regA)
+		case 0x39:
+			fmt.Printf("USERSTAT(DEVICE=%v, STATREC=[%04x], CONTROL=%04x)",
+				regA, t.param(3), t.param(5))
+
+		// Sys
+		case 0x3c:
+			fmt.Printf("SYSREAD(BLOCK=%04x, LEN=%04x, DATA=[%04x], DEVICE=%v, CONTROL=%04x)",
+				t.param(3), t.param(5), t.param(7), t.param(9), t.param(11))
+		case 0x3f:
+			fmt.Printf("SYSWRITE(BLOCK=%04x, LEN=%04x, DATA=[%04x], DEVICE=%v, CONTROL=%04x)",
+				t.param(3), t.param(5), t.param(7), t.param(9), t.param(11))
+		case 0x42:
+			fmt.Printf("SYSCTRL(DEVICE=%v)", regA)
+		case 0x43:
+			fmt.Printf("SYSSTAT(DEVICE=%v, STATREC=[%04x], CONTROL=%04x)",
+				regA, t.param(3), t.param(5))
+
+		default:
+			fmt.Printf("<unknown>")
+		}
+		fmt.Printf("\n")
+	}
+}
+
+func (t *tracePascal) param(index uint8) uint16 {
+	_, sp := t.a.cpu.GetPCAndSP()
+	return uint16(t.a.mmu.Peek(0x100+uint16(sp+index))) +
+		uint16(t.a.mmu.Peek(0x100+uint16(sp+index+1)))<<8 - 2
+}
diff --git a/traceProDOS.go b/traceProDOS.go
index c676c50..49e9829 100644
--- a/traceProDOS.go
+++ b/traceProDOS.go
@@ -67,9 +67,9 @@ func (t *traceProDOS) inspect() {
 }
 
 func (t *traceProDOS) dumpMLICall() {
-	_, ps := t.a.cpu.GetPCAndSP()
-	caller := uint16(t.a.mmu.Peek(0x100+uint16(ps+1))) +
-		uint16(t.a.mmu.Peek(0x100+uint16(ps+2)))<<8 - 2
+	_, sp := t.a.cpu.GetPCAndSP()
+	caller := uint16(t.a.mmu.Peek(0x100+uint16(sp+1))) +
+		uint16(t.a.mmu.Peek(0x100+uint16(sp+2)))<<8 - 2
 	t.functionCode = t.a.mmu.Peek(caller + 3)
 	t.paramsAdddress = uint16(t.a.mmu.Peek(caller+4)) + uint16(t.a.mmu.Peek(caller+5))<<8
 	t.returnAddress = caller + 6