From 3827a084ad85911b9609f95263ab0aa49c10d692 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 28 Nov 2023 23:18:22 -0500
Subject: [PATCH] Code to GlaBIOS expectations.

---
 Components/8272/Status.hpp             |  5 -----
 Components/8272/i8272.cpp              |  2 +-
 Machines/PCCompatible/PCCompatible.cpp | 21 ++++++---------------
 3 files changed, 7 insertions(+), 21 deletions(-)

diff --git a/Components/8272/Status.hpp b/Components/8272/Status.hpp
index cc2f249b0..0a42d95ad 100644
--- a/Components/8272/Status.hpp
+++ b/Components/8272/Status.hpp
@@ -114,11 +114,6 @@ class Status {
 			}
 		}
 
-		void end_sense_interrupt_status(int drive, int head) 	{
-			status_[0] = uint8_t(drive | (head << 2));
-			main_status_ &= ~(1 << drive);
-		}
-
 	private:
 		void set(uint8_t flag, bool value, uint8_t &target) {
 			if(value) {
diff --git a/Components/8272/i8272.cpp b/Components/8272/i8272.cpp
index 97963fa37..638034e75 100644
--- a/Components/8272/i8272.cpp
+++ b/Components/8272/i8272.cpp
@@ -708,7 +708,7 @@ void i8272::posit_event(int event_type) {
 				// If a drive was found, return its results. Otherwise return a single 0x80.
 				if(found_drive != -1) {
 					drives_[found_drive].phase = Drive::NotSeeking;
-					status_.end_sense_interrupt_status(found_drive, 0);
+//					status_.end_sense_interrupt_status(found_drive, 0);
 					status_.set(Status0::SeekEnded);
 
 					result_stack_ = { drives_[found_drive].head_position, status_[0]};
diff --git a/Machines/PCCompatible/PCCompatible.cpp b/Machines/PCCompatible/PCCompatible.cpp
index e35357479..fec083f72 100644
--- a/Machines/PCCompatible/PCCompatible.cpp
+++ b/Machines/PCCompatible/PCCompatible.cpp
@@ -92,19 +92,7 @@ class FloppyController {
 					case Command::SenseInterruptStatus:
 						printf("FDC: SenseInterruptStatus\n");
 						pic_.apply_edge<6>(false);
-
-						if(interrupting_drives_) {
-							int drive = 3;
-							while(!(interrupting_drives_ & (1 << drive))) {
-								--drive;
-							}
-							interrupting_drives_ &= ~(1 << drive);
-
-							status_.end_sense_interrupt_status(drive, 0);
-							results_.serialise(status_, 10);
-						} else {
-							results_.serialise_none();
-						}
+						results_.serialise(status_, 0);	// TODO: get track of relevant drive.
 					break;
 				}
 
@@ -146,7 +134,11 @@ class FloppyController {
 			decoder_.clear();
 			status_.reset();
 			pic_.apply_edge<6>(true);
-			interrupting_drives_ = 0xf;
+
+			// Necessary to pass GlaBIOS [if this is called after reset?], but Why?
+			//
+			// Cf. INT_13_0_2 and the CMP	AL, 11000000B following a CALL	FDC_WAIT_SENSE.
+			status_.set(Intel::i8272::Status0::BecameNotReady);
 
 			using MainStatus = Intel::i8272::MainStatus;
 			status_.set(MainStatus::DataReady, true);
@@ -162,7 +154,6 @@ class FloppyController {
 		Intel::i8272::CommandDecoder decoder_;
 		Intel::i8272::Status status_;
 		Intel::i8272::Results results_;
-		int interrupting_drives_ = 0;
 };
 
 class KeyboardController {