1 files changed, 6 insertions, 1 deletions
diff --git a/src/cpu.c b/src/cpu.c
index 5b73724..e2f0ad0 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -1,4 +1,5 @@
 #include "cpu.h"
+#include <stdio.h>
 
 #define FZ 0x80
 #define FN 0x40
@@ -407,7 +408,11 @@ int cpu_step(GB *gb) {
 
     case 0xCB: do_cb(gb); break;
 
-    case 0xED: gb->poweroff = true; break;  // (illegal on HW) clean-exit signal
+    case 0xED: gb->poweroff = true;         // (illegal on HW) clean-exit signal
+        fprintf(stderr, "[sl0pboy] poweroff opcode $ED at pc=%04X (af=%04X bc=%04X "
+                "de=%04X hl=%04X sp=%04X)\n", (unsigned)(c->pc - 1), c->af, c->bc,
+                c->de, c->hl, c->sp);
+        break;
 
     default:
         // 0x40-0xBF block: LD r,r' and ALU A,r