From c7c55528e2658328bc49cd81d3c1ed1090c3472d Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Mon, 6 Jun 2016 20:29:39 -0400
Subject: [PATCH] Realised that registers appear also to be readable.

---
 Components/6560/6560.cpp  | 7 +++++++
 Components/6560/6560.hpp  | 3 +++
 Machines/Vic-20/Vic20.cpp | 4 ++++
 Machines/Vic-20/Vic20.hpp | 4 ++--
 4 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/Components/6560/6560.cpp b/Components/6560/6560.cpp
index a4f34c121..9781f5657 100644
--- a/Components/6560/6560.cpp
+++ b/Components/6560/6560.cpp
@@ -50,6 +50,7 @@ MOS6560::MOS6560() :
 
 void MOS6560::set_register(int address, uint8_t value)
 {
+	_registers[address] = value;
 	switch(address)
 	{
 		case 0x0:
@@ -99,6 +100,12 @@ void MOS6560::set_register(int address, uint8_t value)
 	}
 }
 
+uint8_t MOS6560::get_register(int address)
+{
+	return _registers[address];
+}
+
+
 void MOS6560::output_border(unsigned int number_of_cycles)
 {
 	uint8_t *colour_pointer = _crt->allocate_write_area(1);
diff --git a/Components/6560/6560.hpp b/Components/6560/6560.hpp
index 554ea8b7a..21a7da4f3 100644
--- a/Components/6560/6560.hpp
+++ b/Components/6560/6560.hpp
@@ -22,6 +22,7 @@ class MOS6560 {
 		void set_graphics_value(uint8_t value, uint8_t colour_value);
 
 		void set_register(int address, uint8_t value);
+		uint8_t get_register(int address);
 
 	private:
 		std::unique_ptr<Outputs::CRT::CRT> _crt;
@@ -47,6 +48,8 @@ class MOS6560 {
 
 		uint8_t *pixel_pointer;
 
+		uint8_t _registers[16];
+
 		void output_border(unsigned int number_of_cycles);
 };
 
diff --git a/Machines/Vic-20/Vic20.cpp b/Machines/Vic-20/Vic20.cpp
index ed3b72ca6..249d16cd2 100644
--- a/Machines/Vic-20/Vic20.cpp
+++ b/Machines/Vic-20/Vic20.cpp
@@ -29,6 +29,10 @@ unsigned int Machine::perform_bus_operation(CPU6502::BusOperation operation, uin
 	if(isReadOperation(operation))
 	{
 		*value = read_memory(address);
+		if((address&0xfff0) == 0x9000)
+		{
+			*value = _mos6560->get_register(address - 0x9000);
+		}
 	}
 	else
 	{
diff --git a/Machines/Vic-20/Vic20.hpp b/Machines/Vic-20/Vic20.hpp
index b4af33e4b..460355d8d 100644
--- a/Machines/Vic-20/Vic20.hpp
+++ b/Machines/Vic-20/Vic20.hpp
@@ -46,12 +46,12 @@ class Machine: public CPU6502::Processor<Machine>, public CRTMachine::Machine {
 
 		uint8_t _userBASICMemory[0x0400];
 		uint8_t _screenMemory[0x1000];
-		uint8_t _colorMemory[0x0200];
+		uint8_t _colorMemory[0x0400];
 
 		inline uint8_t *ram_pointer(uint16_t address) {
 			if(address < sizeof(_userBASICMemory)) return &_userBASICMemory[address];
 			if(address >= 0x1000 && address < 0x2000) return &_screenMemory[address&0x0fff];
-			if(address >= 0x9400 && address < 0x9600) return &_colorMemory[0x01ff];
+			if(address >= 0x9400 && address < 0x9800) return &_colorMemory[0x03ff];	// TODO: make this 4-bit
 			return nullptr;
 		}