From c206c7e2cbcad7e4ebba71e3163428bc4266c3b2 Mon Sep 17 00:00:00 2001
From: Ryan Schmidt <git@ryandesign.com>
Date: Wed, 25 Oct 2023 01:44:48 -0500
Subject: [PATCH] Fix Apple II/II+ text/lores hbl read addresses

Closes #1181
---
 Machines/Apple/AppleII/Video.hpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Machines/Apple/AppleII/Video.hpp b/Machines/Apple/AppleII/Video.hpp
index 72245c22e..c2e947a3a 100644
--- a/Machines/Apple/AppleII/Video.hpp
+++ b/Machines/Apple/AppleII/Video.hpp
@@ -178,6 +178,13 @@ template <class BusHandler, bool is_iie> class Video: public VideoBase {
 				if(mapped_row < 64) {
 					read_address += 128;
 				}
+
+				// On Apple II and II+ (not IIe or later) in text/lores mode (not hires), horizontal
+				// blanking bytes read from $1000 higher.
+				const GraphicsMode pixel_mode = graphics_mode(mapped_row);
+				if(!is_iie_ && ((pixel_mode == GraphicsMode::Text) || (pixel_mode == GraphicsMode::LowRes))) {
+					read_address += 0x1000;
+				}
 			}
 
 			// Read the address and return the value.