From 282d0f1ebb19adbb034c74dfaee32fc943cd0209 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 5 Nov 2020 18:17:21 -0500
Subject: [PATCH] For debugging, adds a dump of anything in the [presumably]
 text buffer.

Nothing is there.
---
 Machines/Apple/AppleIIgs/AppleIIgs.cpp |  1 +
 Machines/Apple/AppleIIgs/Video.cpp     | 23 +++++++++++++++++++++++
 Machines/Apple/AppleIIgs/Video.hpp     |  2 ++
 3 files changed, 26 insertions(+)

diff --git a/Machines/Apple/AppleIIgs/AppleIIgs.cpp b/Machines/Apple/AppleIIgs/AppleIIgs.cpp
index 1f84209d3..218330c6c 100644
--- a/Machines/Apple/AppleIIgs/AppleIIgs.cpp
+++ b/Machines/Apple/AppleIIgs/AppleIIgs.cpp
@@ -84,6 +84,7 @@ class ConcreteMachine:
 			ram_.resize(ram_size * 1024);
 
 			memory_.set_storage(ram_, rom_);
+			video_.set_internal_ram(&ram_[ram_.size() - 128*1024]);
 
 			// TODO: enable once machine is otherwise sane.
 //			Memory::Fuzz(ram_);
diff --git a/Machines/Apple/AppleIIgs/Video.cpp b/Machines/Apple/AppleIIgs/Video.cpp
index bd47bae9f..7b2b4639e 100644
--- a/Machines/Apple/AppleIIgs/Video.cpp
+++ b/Machines/Apple/AppleIIgs/Video.cpp
@@ -22,12 +22,35 @@ VideoBase::VideoBase() :
 	VideoSwitches<Cycles>(Cycles(2), [] (Cycles) {}) {
 }
 
+void VideoBase::set_internal_ram(const uint8_t *ram) {
+	ram_ = ram;
+}
+
 void VideoBase::did_set_annunciator_3(bool) {}
 void VideoBase::did_set_alternative_character_set(bool) {}
 
 void VideoBase::run_for(Cycles cycles) {
 	// TODO: everything else!
+	const auto old = cycles_into_frame_;
 	cycles_into_frame_ = (cycles_into_frame_ + cycles.as<int>()) % (CyclesPerLine * Lines);
+
+	// DEBUGGING HACK!!
+	// Scan the output buffer, assuming this is 40-column text mode, and print anything found.
+	if(cycles_into_frame_ < old) {
+		for(int line = 0; line < 192; line += 8) {
+			const uint16_t address = get_row_address(line);
+
+			bool did_print_line = false;
+			for(int column = 0; column < 40; column++) {
+				const char c = char(ram_[address + column]);
+				if(c > 0) {
+					printf("%c", c);
+					did_print_line = true;
+				}
+			}
+			if(did_print_line) printf("\n");
+		}
+	}
 }
 
 bool VideoBase::get_is_vertical_blank() {
diff --git a/Machines/Apple/AppleIIgs/Video.hpp b/Machines/Apple/AppleIIgs/Video.hpp
index a85f75085..1e6038377 100644
--- a/Machines/Apple/AppleIIgs/Video.hpp
+++ b/Machines/Apple/AppleIIgs/Video.hpp
@@ -19,6 +19,7 @@ namespace Video {
 class VideoBase: public Apple::II::VideoSwitches<Cycles> {
 	public:
 		VideoBase();
+		void set_internal_ram(const uint8_t *);
 
 		void run_for(Cycles);
 		bool get_is_vertical_blank();
@@ -41,6 +42,7 @@ class VideoBase: public Apple::II::VideoSwitches<Cycles> {
 		void set_interrupts(uint8_t);
 
 		int cycles_into_frame_ = 0;
+		const uint8_t *ram_ = nullptr;
 };
 
 class Video: public VideoBase {