From 13a608a8c2f063cf18bc9867e4ebff52b02833d8 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 22 Nov 2016 22:09:52 +0800
Subject: [PATCH] Added what may be correct paging logic.

---
 Machines/Oric/Microdisc.cpp | 18 ++++++++++++++----
 Machines/Oric/Microdisc.hpp | 14 ++++++++++++++
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/Machines/Oric/Microdisc.cpp b/Machines/Oric/Microdisc.cpp
index 00454cd19..0a9ccb5d9 100644
--- a/Machines/Oric/Microdisc.cpp
+++ b/Machines/Oric/Microdisc.cpp
@@ -10,7 +10,10 @@
 
 using namespace Oric;
 
-Microdisc::Microdisc() : irq_enable_(false)
+Microdisc::Microdisc() :
+	irq_enable_(false),
+	delegate_(nullptr),
+	paging_flags_(BASICDisable)
 {}
 
 void Microdisc::set_disk(std::shared_ptr<Storage::Disk::Disk> disk, int drive)
@@ -25,9 +28,7 @@ void Microdisc::set_disk(std::shared_ptr<Storage::Disk::Disk> disk, int drive)
 
 void Microdisc::set_control_register(uint8_t control)
 {
-	// b7: EPROM select (0 = select)
-	// b2: data separator clock rate select (1 = double)
-	// b1: ROM disable (0 = disable)
+	// b2: data separator clock rate select (1 = double)	[TODO]
 
 	// b65: drive select
 	selected_drive_ = (control >> 5)&3;
@@ -44,6 +45,15 @@ void Microdisc::set_control_register(uint8_t control)
 
 	// b0: IRQ enable
 	irq_enable_ = !(control & 0x01);
+
+	// b7: EPROM select (0 = select)
+	// b1: ROM disable (0 = disable)
+	int new_paging_flags = ((control & 0x01) ? BASICDisable : 0) | ((control & 0x80) ? 0 : MicrodscDisable);
+	if(new_paging_flags != paging_flags_)
+	{
+		paging_flags_ = new_paging_flags;
+		if(delegate_) delegate_->microdisc_did_change_paging_flags(this);
+	}
 }
 
 bool Microdisc::get_interrupt_request_line()
diff --git a/Machines/Oric/Microdisc.hpp b/Machines/Oric/Microdisc.hpp
index ec728c48e..fcbe21b1a 100644
--- a/Machines/Oric/Microdisc.hpp
+++ b/Machines/Oric/Microdisc.hpp
@@ -24,10 +24,24 @@ class Microdisc: public WD::WD1770 {
 
 		bool get_interrupt_request_line();
 
+		enum PagingFlags {
+			BASICDisable	=	(1 << 0),
+			MicrodscDisable	=	(1 << 1)
+		};
+
+		class Delegate {
+			public:
+				virtual void microdisc_did_change_paging_flags(Microdisc *microdisc) = 0;
+		};
+		inline void set_microdisc_delegate(Delegate *delegate)	{	delegate_ = delegate;	}
+		inline int get_paging_flags()							{	return paging_flags_;	}
+
 	private:
 		std::shared_ptr<Storage::Disk::Drive> drives_[4];
 		int selected_drive_;
 		bool irq_enable_;
+		int paging_flags_;
+		Delegate *delegate_;
 };
 
 }