A patch for Blastem emulator to obtain all values that program counter had through the game that you were playing. Very handy for disassembling Sega Mega Drive / Genesis games. https://github.com/libretro/blastem, commit 277e4a62668597d4f59cadda1cbafb844f981d45.

blastem-pc-trace-on-277e4a62668597d4f59cadda1cbafb844f981d45.patch

diff --git a/bindings.c b/bindings.c
index 2921aa8..bdacf0e 100644
--- a/bindings.c
+++ b/bindings.c
@@ -292,6 +292,40 @@ https://github.com/libretro/blastem, commit 277e4a62668597d4f59cadda1cbafb844f981d45
 	return path;
 }
 
+#define ROM_SIZE ((size_t)(4*1024*1024))
+static unsigned char pc_map[ROM_SIZE] = {0};
+
+#include <assert.h>
+#include <errno.h>
+
+void trace_pc(uint32_t pc)
+{
+	assert(pc < ROM_SIZE);
+	pc_map[pc] = 1;
+}
+
+static void dump_pc(void)
+{
+	const char *file_name = "/tmp/trace.txt";
+	FILE *out = fopen(file_name, "w");
+	if (out == NULL) {
+		const int err = errno;
+		fprintf(
+				stderr,
+				"dump_pc: fopen(\"%s\", \"r\"): Error (%d): \"%s\"\n",
+				file_name,
+				err,
+				strerror(err));
+		return;
+	}
+	for (size_t i = 0; i < ROM_SIZE; i++) {
+		if (pc_map[i]) {
+			fprintf(out, "%zu\n", i);
+		}
+	}
+	fclose(out);
+}
+
 void handle_binding_up(keybinding * binding)
 {
 	uint8_t allow_content_binds = content_binds_enabled && current_system;
@@ -324,6 +358,7 @@ void handle_binding_up(keybinding * binding)
 			if (allow_content_binds) {
 				current_system->save_state = QUICK_SAVE_SLOT+1;
 			}
+			dump_pc();
 			break;
 		case UI_NEXT_SPEED:
 			if (allow_content_binds) {
diff --git a/m68k_core.c b/m68k_core.c
index cd975cb..66b2a99 100644
--- a/m68k_core.c
+++ b/m68k_core.c
@@ -1021,6 +1021,8 @@ void translate_m68k_stream(uint32_t address, m68k_context * context)
 			fflush(opts->address_log);
 		}
 		do {
+			extern void trace_pc(uint32_t);
+			trace_pc(address);
 			encoded = get_native_pointer(address, (void **)context->mem_pointers, &opts->gen);
 			if (!encoded) {
 				code_ptr start = code->cur;