From 98751e6ac88498c888d6d72114926eb7a5a1798c Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 15 Sep 2017 22:59:26 -0400
Subject: [PATCH] Ensures that all result phases are exactly the intended
 length by replacing accumulation with assignment.

Also attempts a different version of control mark behaviour. Experiments.
---
 Components/8272/i8272.cpp | 34 +++++++++++++++-------------------
 1 file changed, 15 insertions(+), 19 deletions(-)

diff --git a/Components/8272/i8272.cpp b/Components/8272/i8272.cpp
index 3f02acf15..af26b4812 100644
--- a/Components/8272/i8272.cpp
+++ b/Components/8272/i8272.cpp
@@ -44,6 +44,7 @@ using namespace Intel::i8272;
 #define SetMissingAddressMark()			(status_[1] |= 0x01)
 
 #define SetControlMark()				(status_[2] |= 0x40)
+#define ClearControlMark()				(status_[2] &= ~0x40)
 #define ControlMark()					(status_[2] & 0x40)
 
 #define SetDataFieldDataError()			(status_[2] |= 0x20)
@@ -437,6 +438,7 @@ void i8272::posit_event(int event_type) {
 		// flag doesn't match the sort the command was looking for.
 		read_data_found_header:
 			FIND_DATA();
+			ClearControlMark();
 			if(event_type == (int)Event::Token) {
 				if(get_latest_token().type != Token::Data && get_latest_token().type != Token::DeletedData) {
 					// Something other than a data mark came next — impliedly an ID or index mark.
@@ -779,10 +781,9 @@ void i8272::posit_event(int event_type) {
 					main_status_ &= ~(1 << found_drive);
 					SetSeekEnd();
 
-					result_stack_.push_back(drives_[found_drive].head_position);
-					result_stack_.push_back(status_[0]);
+					result_stack_ = { drives_[found_drive].head_position, status_[0]};
 				} else {
-					result_stack_.push_back(0x80);
+					result_stack_ = { 0x80 };
 				}
 			}
 			goto post_result;
@@ -805,20 +806,22 @@ void i8272::posit_event(int event_type) {
 			{
 				int drive = command_[1] & 3;
 				select_drive(drive);
-				result_stack_.push_back(
-					(command_[1] & 7) |	// drive and head number
-					0x08 |				// single sided
-					(get_drive().get_is_track_zero() ? 0x10 : 0x00)	|
-					(get_drive().get_is_ready() ? 0x20 : 0x00)		|
-					(get_drive().get_is_read_only() ? 0x40 : 0x00)
-				);
+				result_stack_= {
+					static_cast<uint8_t>(
+						(command_[1] & 7) |	// drive and head number
+						0x08 |				// single sided
+						(get_drive().get_is_track_zero() ? 0x10 : 0x00)	|
+						(get_drive().get_is_ready() ? 0x20 : 0x00)		|
+						(get_drive().get_is_read_only() ? 0x40 : 0x00)
+					)
+				};
 			}
 			goto post_result;
 
 	// Performs any invalid command.
 	invalid:
 			// A no-op, but posts ST0 (but which ST0?)
-			result_stack_.push_back(0x80);
+			result_stack_ = {0x80};
 			goto post_result;
 
 	// Sets abnormal termination of the current command and proceeds to an ST0, ST1, ST2, C, H, R, N result phase.
@@ -831,14 +834,7 @@ void i8272::posit_event(int event_type) {
 	post_st012chrn:
 			SCHEDULE_HEAD_UNLOAD();
 
-			result_stack_.push_back(size_);
-			result_stack_.push_back(sector_);
-			result_stack_.push_back(head_);
-			result_stack_.push_back(cylinder_);
-
-			result_stack_.push_back(status_[2]);
-			result_stack_.push_back(status_[1]);
-			result_stack_.push_back(status_[0]);
+			result_stack_ = {size_, sector_, head_, cylinder_, status_[2], status_[1], status_[0]};
 
 			goto post_result;