From 5e4fca1c61d00caee2db04fa836ac5019e4bafcc Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Wed, 20 May 2026 13:42:17 -0400
Subject: [PATCH] Halt _until_ data is available; do it only once.

---
 Machines/Tandy/CoCo/DiskController.cpp | 6 ++++--
 Machines/Tandy/CoCo/DiskController.hpp | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/Machines/Tandy/CoCo/DiskController.cpp b/Machines/Tandy/CoCo/DiskController.cpp
index 8e08f2fac..11fb36644 100644
--- a/Machines/Tandy/CoCo/DiskController.cpp
+++ b/Machines/Tandy/CoCo/DiskController.cpp
@@ -61,8 +61,10 @@ const Storage::Disk::Disk *DiskController::disk(const std::string &name) {
 //	* DRQ informs HALT, if enabled.
 //
 
-bool DiskController::halt() const {
-	return get_data_request_line() && enable_halt_;
+bool DiskController::halt() {
+	const bool halt = !get_data_request_line() && enable_halt_;
+	if(halt) enable_halt_ = false;
+	return halt;
 }
 
 bool DiskController::nmi() const {
diff --git a/Machines/Tandy/CoCo/DiskController.hpp b/Machines/Tandy/CoCo/DiskController.hpp
index 5d2d3e947..b2a2d8cd4 100644
--- a/Machines/Tandy/CoCo/DiskController.hpp
+++ b/Machines/Tandy/CoCo/DiskController.hpp
@@ -43,7 +43,7 @@ public:
 	void set_disk(std::shared_ptr<Storage::Disk::Disk>, size_t drive);
 	const Storage::Disk::Disk *disk(const std::string &);
 
-	bool halt() const;
+	bool halt();
 	bool nmi() const;
 
 private: