From 3bb3d8c5c1e4a01a0f223dcae682a91995c111f7 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sat, 7 Nov 2020 23:14:50 -0500
Subject: [PATCH] Adds text colour register.

Oddly this isn't currently being set. So probably another latent fault elsewhere.
---
 Machines/Apple/AppleIIgs/AppleIIgs.cpp | 10 ++++++++--
 Machines/Apple/AppleIIgs/Video.cpp     | 11 +++++++++--
 Machines/Apple/AppleIIgs/Video.hpp     |  6 ++++++
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/Machines/Apple/AppleIIgs/AppleIIgs.cpp b/Machines/Apple/AppleIIgs/AppleIIgs.cpp
index 2780f29c1..9d607ed31 100644
--- a/Machines/Apple/AppleIIgs/AppleIIgs.cpp
+++ b/Machines/Apple/AppleIIgs/AppleIIgs.cpp
@@ -187,8 +187,14 @@ class ConcreteMachine:
 							*value = clock_.get_control();
 						} else {
 							clock_.set_control(*value);
-							video_->set_border_colour(*value & 0xf);
-							// TODO: also set border colour.
+							video_->set_border_colour(*value);
+						}
+					break;
+
+					// Colour text control.
+					case 0xc022:
+						if(!is_read) {
+							video_->set_text_colour(*value);
 						}
 					break;
 
diff --git a/Machines/Apple/AppleIIgs/Video.cpp b/Machines/Apple/AppleIIgs/Video.cpp
index 02acd098f..9363ebd3c 100644
--- a/Machines/Apple/AppleIIgs/Video.cpp
+++ b/Machines/Apple/AppleIIgs/Video.cpp
@@ -152,7 +152,7 @@ void VideoBase::output_row(int row, int start, int end) {
 	}
 
 	// Possibly output border, pixels, border, if this is a pixel line.
-	if(row < 200) {	// TODO: use real test here; should be 192 for classic Apple II modes.
+	if(row < 192 + ((new_video_&0x80) >> 4)) {	// i.e. 192 lines for classic Apple II video, 200 for IIgs video.
 
 		// Output left border as far as currently known.
 		if(start >= start_of_left_border && start < start_of_pixels) {
@@ -211,6 +211,8 @@ void VideoBase::output_row(int row, int start, int end) {
 }
 
 bool VideoBase::get_is_vertical_blank() {
+	// Cf. http://www.1000bit.it/support/manuali/apple/technotes/iigs/tn.iigs.040.html ;
+	// this bit covers the entire vertical border area, not just the NTSC-sense vertical blank.
 	return cycles_into_frame_ >= FinalPixelLine * CyclesPerLine;
 }
 
@@ -245,5 +247,10 @@ void VideoBase::set_interrupts(uint8_t new_value) {
 }
 
 void VideoBase::set_border_colour(uint8_t colour) {
-	border_colour_ = appleii_palette[colour];
+	border_colour_ = appleii_palette[colour & 0xf];
+}
+
+void VideoBase::set_text_colour(uint8_t colour) {
+	text_colour_ = appleii_palette[colour >> 4];
+	background_colour_ = appleii_palette[colour & 0xf];
 }
diff --git a/Machines/Apple/AppleIIgs/Video.hpp b/Machines/Apple/AppleIIgs/Video.hpp
index f5e29b7f4..fb12a081d 100644
--- a/Machines/Apple/AppleIIgs/Video.hpp
+++ b/Machines/Apple/AppleIIgs/Video.hpp
@@ -37,7 +37,9 @@ class VideoBase: public Apple::II::VideoSwitches<Cycles> {
 		void set_interrupt_register(uint8_t);
 
 		void notify_clock_tick();
+
 		void set_border_colour(uint8_t);
+		void set_text_colour(uint8_t);
 
 		/// Sets the scan target.
 		void set_scan_target(Outputs::Display::ScanTarget *scan_target);
@@ -62,7 +64,11 @@ class VideoBase: public Apple::II::VideoSwitches<Cycles> {
 
 		int cycles_into_frame_ = 0;
 		const uint8_t *ram_ = nullptr;
+
+		// The modal colours.
 		uint16_t border_colour_ = 0;
+		uint16_t text_colour_ = 0xfff;
+		uint16_t background_colour_ = 0;
 
 		void output_row(int row, int start, int end);
 };