From cf3b1495949b5e22fbcaac0510cfe002b2cccb16 Mon Sep 17 00:00:00 2001
From: Andre Weissflog <floooh@gmail.com>
Date: Mon, 9 Dec 2024 12:21:55 +0100
Subject: [PATCH] z80: prevent infinite loop when op-stepping with wait active
 (fixes #22)

---
 src/sim.c   | 2 +-
 src/trace.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/sim.c b/src/sim.c
index c5a59e5..390cbda 100644
--- a/src/sim.c
+++ b/src/sim.c
@@ -122,7 +122,7 @@ void sim_step_op(void) {
             prev_m1 = cpu_readM1(sim.cpu_state);
             sim_step(1);
             cur_m1 = cpu_readM1(sim.cpu_state);
-        } while (!(prev_m1 && !cur_m1));   // M1 pin is active-low!
+        } while (!(prev_m1 && !cur_m1) && cpu_readWAIT(sim.cpu_state));   // M1 pin is active-low!
     #endif
 }
 
diff --git a/src/trace.c b/src/trace.c
index 42c4bea..a39a59b 100644
--- a/src/trace.c
+++ b/src/trace.c
@@ -429,7 +429,7 @@ uint8_t trace_z80_get_mcycle(uint32_t index) {
         case (1<<2): return 3;
         case (1<<3): return 4;
         case (1<<4): return 5;
-        default: return 0xFF;
+        default: return 0;
     }
 }
 
@@ -441,7 +441,7 @@ uint8_t trace_z80_get_tstate(uint32_t index) {
         case (1<<3): return 4;
         case (1<<4): return 5;
         case (1<<5): return 6;
-        default: return 0xFF;
+        default: return 0;
     }
 }