From 4ee8f8564eadc9be55140cfce2ffc20aef690f35 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 21 Oct 2025 13:40:23 -0400
Subject: [PATCH] Catch unimplemented.

---
 Machines/Acorn/BBCMicro/BBCMicro.cpp       | 2 +-
 Processors/6502Mk2/Implementation/6502.hpp | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/Machines/Acorn/BBCMicro/BBCMicro.cpp b/Machines/Acorn/BBCMicro/BBCMicro.cpp
index d474547e8..ac8135173 100644
--- a/Machines/Acorn/BBCMicro/BBCMicro.cpp
+++ b/Machines/Acorn/BBCMicro/BBCMicro.cpp
@@ -1177,7 +1177,7 @@ struct Traits {
 void test_it() {
 	Handler handler;
 	CPU::MOS6502Mk2::Processor<CPU::MOS6502Mk2::Model::M6502, Traits> processor(handler);
-	processor.run_for(Cycles(10));
+	processor.run_for(Cycles(1000));
 }
 
 }
diff --git a/Processors/6502Mk2/Implementation/6502.hpp b/Processors/6502Mk2/Implementation/6502.hpp
index b3667cead..c446acf81 100644
--- a/Processors/6502Mk2/Implementation/6502.hpp
+++ b/Processors/6502Mk2/Implementation/6502.hpp
@@ -61,6 +61,9 @@ void Processor<model, Traits>::run_for(const Cycles cycles) {
 	using InterruptRequest = Storage::Inputs::InterruptRequest;
 
 	while(true) switch(Storage::resume_point_) {
+		default:
+			__builtin_unreachable();
+
 		// MARK: - Fetch/decode.
 		fetch_decode:
 		case ResumePoint::FetchDecode: