From 1b43381be0223ad97962ec98bc44da06f97286c4 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 24 May 2018 18:53:02 -0400
Subject: [PATCH 1/2] Corrects meaning of the Microdisc's paging control.

---
 Machines/Oric/Oric.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Machines/Oric/Oric.cpp b/Machines/Oric/Oric.cpp
index 4e4ebf153..cbdc3a9cc 100644
--- a/Machines/Oric/Oric.cpp
+++ b/Machines/Oric/Oric.cpp
@@ -504,11 +504,11 @@ template <Analyser::Static::Oric::Target::DiskInterface disk_interface> class Co
 		void microdisc_did_change_paging_flags(class Microdisc *microdisc) override final {
 			int flags = microdisc->get_paging_flags();
 			if(!(flags&Microdisc::PagingFlags::BASICDisable)) {
-				ram_top_ = basic_invisible_ram_top_;
+				ram_top_ = basic_visible_ram_top_;
 				paged_rom_ = rom_.data();
 			} else {
 				if(flags&Microdisc::PagingFlags::MicrodscDisable) {
-					ram_top_ = basic_visible_ram_top_;
+					ram_top_ = basic_invisible_ram_top_;
 				} else {
 					ram_top_ = 0xdfff;
 					paged_rom_ = microdisc_rom_.data();

From 7c3dd55e5ccce4b75122926aba449740a2181ccc Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 24 May 2018 18:57:35 -0400
Subject: [PATCH 2/2] Corrects typo and improves exposition.

---
 Machines/Oric/Microdisc.cpp |  2 +-
 Machines/Oric/Microdisc.hpp | 10 ++++++++--
 Machines/Oric/Oric.cpp      |  2 +-
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/Machines/Oric/Microdisc.cpp b/Machines/Oric/Microdisc.cpp
index 6f5a200d3..d31114b2d 100644
--- a/Machines/Oric/Microdisc.cpp
+++ b/Machines/Oric/Microdisc.cpp
@@ -72,7 +72,7 @@ void Microdisc::set_control_register(uint8_t control, uint8_t changes) {
 	// b7: EPROM select (0 = select)
 	// b1: ROM disable (0 = disable)
 	if(changes & 0x82) {
-		paging_flags_ = ((control & 0x02) ? 0 : BASICDisable) | ((control & 0x80) ? MicrodscDisable : 0);
+		paging_flags_ = ((control & 0x02) ? 0 : BASICDisable) | ((control & 0x80) ? MicrodiscDisable : 0);
 		if(delegate_) delegate_->microdisc_did_change_paging_flags(this);
 	}
 }
diff --git a/Machines/Oric/Microdisc.hpp b/Machines/Oric/Microdisc.hpp
index a935b222e..3aef6aefe 100644
--- a/Machines/Oric/Microdisc.hpp
+++ b/Machines/Oric/Microdisc.hpp
@@ -31,8 +31,14 @@ class Microdisc: public WD::WD1770 {
 		using WD::WD1770::run_for;
 
 		enum PagingFlags {
-			BASICDisable	=	(1 << 0),
-			MicrodscDisable	=	(1 << 1)
+			/// Indicates that the BASIC ROM should be disabled; if this is set then either
+			/// the Microdisc ROM or overlay RAM will be visible. If it is not set, BASIC
+			/// should be visible.
+			BASICDisable		=	(1 << 0),
+
+			/// Indicates that the Microdisc ROM is disabled. If BASIC is disabled and the Microdisc
+			/// is also disabled, overlay RAM should be visible.
+			MicrodiscDisable	=	(1 << 1)
 		};
 
 		class Delegate: public WD1770::Delegate {
diff --git a/Machines/Oric/Oric.cpp b/Machines/Oric/Oric.cpp
index cbdc3a9cc..30b7c1c39 100644
--- a/Machines/Oric/Oric.cpp
+++ b/Machines/Oric/Oric.cpp
@@ -507,7 +507,7 @@ template <Analyser::Static::Oric::Target::DiskInterface disk_interface> class Co
 				ram_top_ = basic_visible_ram_top_;
 				paged_rom_ = rom_.data();
 			} else {
-				if(flags&Microdisc::PagingFlags::MicrodscDisable) {
+				if(flags&Microdisc::PagingFlags::MicrodiscDisable) {
 					ram_top_ = basic_invisible_ram_top_;
 				} else {
 					ram_top_ = 0xdfff;