From 9b228a4e756278a87fadaf7b00438c43e3764f12 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Iv=C3=A1n=20Izaguirre?= <ivanizag@gmail.com>
Date: Thu, 30 Jan 2025 23:36:44 +0100
Subject: [PATCH] Trace monitor calls

---
 README.md       |   1 +
 traceBuilder.go |   5 +++
 traceMonitor.go | 110 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 116 insertions(+)
 create mode 100644 traceMonitor.go

diff --git a/README.md b/README.md
index aa66be5..59063f3 100644
--- a/README.md
+++ b/README.md
@@ -279,6 +279,7 @@ The available tracers are:
   mos: Trace MOS calls with Applecorn skipping terminal IO
   mosfull: Trace MOS calls with Applecorn
   panicss: Panic on unimplemented softswitches
+  rom: Trace monitor ROM calls
   ss: Trace sotfswiches calls
   ssreg: Trace sotfswiches registrations
   ucsd: Trace UCSD system calls
diff --git a/traceBuilder.go b/traceBuilder.go
index 3a2b5db..43f2df8 100644
--- a/traceBuilder.go
+++ b/traceBuilder.go
@@ -92,6 +92,11 @@ func getTracerFactory() map[string]*traceBuilder {
 		description:     "Trace CPM BDOS calls",
 		executionTracer: newTraceCpm(false),
 	}
+	tracerFactory["rom"] = &traceBuilder{
+		name:            "rom",
+		description:     "Trace monitor ROM calls",
+		executionTracer: newTraceMonitor(),
+	}
 	return tracerFactory
 }
 
diff --git a/traceMonitor.go b/traceMonitor.go
new file mode 100644
index 0000000..665a58a
--- /dev/null
+++ b/traceMonitor.go
@@ -0,0 +1,110 @@
+package izapple2
+
+import (
+	"fmt"
+)
+
+/*
+
+	Trace the inpit and output of using the wozmon calls.
+
+*/
+
+type traceMonitor struct {
+	a             *Apple2
+	closingBuffer bool
+	buffer        string
+}
+
+const (
+	wozmonPrompt uint16 = 0x0033
+
+	wozmonGETLNZ      uint16 = 0xfd67
+	woamonGETLN       uint16 = 0xfd6a
+	wozmonGETLNReturn uint16 = 0xfd90
+	wozmonRDCHAR      uint16 = 0xfd35
+	wozmonRDKEY       uint16 = 0xfd0c
+	wozmonKEYIN       uint16 = 0xfd1b
+
+	wozmonCOUT  uint16 = 0xfded
+	wozmonCOUT1 uint16 = 0xfdf0
+	wozmonCOUTZ uint16 = 0xfdf6
+)
+
+func newTraceMonitor() *traceMonitor {
+	var t traceMonitor
+	return &t
+}
+
+func (t *traceMonitor) connect(a *Apple2) {
+	t.a = a
+}
+
+func (t *traceMonitor) inspect() {
+	if t.a.dmaActive {
+		return
+	}
+
+	if t.a.mmu.altMainRAMActiveRead {
+		// We want to trace only the activity on the ROM
+		return
+	}
+
+	pc, _ := t.a.cpu.GetPCAndSP()
+	a, _, _, _ := t.a.cpu.GetAXYP()
+
+	desc := ""
+	switch pc {
+	case wozmonGETLNZ:
+		desc = "GETLNZ"
+	case woamonGETLN:
+		fmt.Printf("Wozmon output: %s\n", t.buffer)
+		t.buffer = ""
+		desc = "GETLN"
+	case wozmonGETLNReturn:
+		t.closingBuffer = true
+		//desc = "GETLN return"
+	case wozmonRDKEY:
+		//desc = "RDKEY"
+	case wozmonKEYIN:
+		//desc = "KEYIN"
+	case wozmonCOUT:
+		//desc = fmt.Sprintf("COUT  0x%02x %c", a, toAscii(a))
+		if t.closingBuffer {
+			fmt.Printf("Wozmon input: %s\n", t.buffer)
+			t.buffer = ""
+			t.closingBuffer = false
+			desc = fmt.Sprintf("GETLN returns <<%s>>", t.getInputBuffer())
+		}
+	case wozmonCOUT1:
+		t.buffer += string(toAscii(a))
+		//desc = fmt.Sprintf("COUT1 0x%02x %c", a, toAscii(a))
+	case wozmonCOUTZ:
+		desc = "COUTZ"
+	}
+
+	if desc != "" {
+		fmt.Printf("Wozmon call to $%04x %s\n", pc, desc)
+	}
+}
+
+func toAscii(b uint8) rune {
+	b = b & 0x7f
+	if b < 0x20 {
+		return rune(uint16(b) + 0x2400)
+	}
+	return rune(b)
+}
+
+func (t *traceMonitor) getInputBuffer() string {
+	buffer := ""
+	for address := uint16(0x200); address < 0x300; address++ {
+		b := t.a.mmu.Peek(address)
+		buffer += string(toAscii(b))
+		if b == 0x8d {
+			break
+		}
+	}
+
+	return buffer
+}