Development checkin

23 files changed, 1575 insertions, 0 deletions

diff --git a/.cvsignore b/.cvsignore
new file mode 100644
index 0000000..6b59bb1
--- /dev/null
+++ b/.cvsignore
@@ -0,0 +1,5 @@
+build
+ds81.arm9
+ds81.ds.gba
+ds81.elf
+ds81.nds
\ No newline at end of file
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..93d2484
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,136 @@
+# This is a generic DS makefile, as taken from the libnds example programs.
+#
+
+#-------------------------------------------------------------------------------
+.SUFFIXES:
+#-------------------------------------------------------------------------------
+
+ifeq ($(strip $(DEVKITARM)),)
+$(error "Please set DEVKITARM in your environment. export DEVKITARM=<path to>devkitARM")
+endif
+
+include $(DEVKITARM)/ds_rules
+
+#-------------------------------------------------------------------------------
+# TARGET is the name of the output
+# BUILD is the directory where object files & intermediate files will be placed
+# SOURCES is a list of directories containing source code
+# INCLUDES is a list of directories containing extra header files
+#-------------------------------------------------------------------------------
+TARGET		:=	$(shell basename $(CURDIR))
+BUILD		:=	build
+SOURCES		:=	source gbagfx
+DATA		:=	data  
+INCLUDES	:=	include gbagfx
+
+#-------------------------------------------------------------------------------
+# options for code generation
+#-------------------------------------------------------------------------------
+ARCH	:=	-mthumb -mthumb-interwork
+
+# note: arm9tdmi isn't the correct CPU arch, but anything newer and LD
+# *insists* it has a FPU or VFP, and it won't take no for an answer!
+CFLAGS	:=	-g -Wall -O2\
+ 			-mcpu=arm9tdmi -mtune=arm9tdmi -fomit-frame-pointer\
+			-ffast-math \
+			$(ARCH)
+
+CFLAGS	+=	$(INCLUDE) -DARM9
+CXXFLAGS	:= $(CFLAGS)
+
+ASFLAGS	:=	-g $(ARCH)
+LDFLAGS	=	-specs=ds_arm9.specs -g $(ARCH) -mno-fpu -Wl,-Map,$(notdir $*.map)
+
+#-------------------------------------------------------------------------------
+# any extra libraries we wish to link with the project
+#-------------------------------------------------------------------------------
+LIBS	:= -lfat -lnds9
+ 
+ 
+#-------------------------------------------------------------------------------
+# list of directories containing libraries, this must be the top level containing
+# include and lib
+#-------------------------------------------------------------------------------
+LIBDIRS	:=	$(LIBNDS)
+ 
+#-------------------------------------------------------------------------------
+# no real need to edit anything past this point unless you need to add
+# additional rules for different file extensions
+#-------------------------------------------------------------------------------
+ifneq ($(BUILD),$(notdir $(CURDIR)))
+#-------------------------------------------------------------------------------
+ 
+export OUTPUT	:=	$(CURDIR)/$(TARGET)
+ 
+export VPATH	:=	$(foreach dir,$(SOURCES),$(CURDIR)/$(dir)) \
+					$(foreach dir,$(DATA),$(CURDIR)/$(dir))
+
+export DEPSDIR	:=	$(CURDIR)/$(BUILD)
+
+CFILES		:=	$(foreach dir,$(SOURCES),$(notdir $(wildcard $(dir)/*.c)))
+CPPFILES	:=	$(foreach dir,$(SOURCES),$(notdir $(wildcard $(dir)/*.cpp)))
+SFILES		:=	$(foreach dir,$(SOURCES),$(notdir $(wildcard $(dir)/*.s)))
+BINFILES	:=	$(foreach dir,$(DATA),$(notdir $(wildcard $(dir)/*.*)))
+ 
+#---------------------------------------------------------------------------------
+# use CXX for linking C++ projects, CC for standard C
+#---------------------------------------------------------------------------------
+ifeq ($(strip $(CPPFILES)),)
+#---------------------------------------------------------------------------------
+	export LD	:=	$(CC)
+#---------------------------------------------------------------------------------
+else
+#---------------------------------------------------------------------------------
+	export LD	:=	$(CXX)
+#---------------------------------------------------------------------------------
+endif
+#---------------------------------------------------------------------------------
+
+export OFILES	:=	$(addsuffix .o,$(BINFILES)) \
+					$(CPPFILES:.cpp=.o) $(CFILES:.c=.o) $(SFILES:.s=.o)
+ 
+export INCLUDE	:=	$(foreach dir,$(INCLUDES),-I$(CURDIR)/$(dir)) \
+					$(foreach dir,$(LIBDIRS),-I$(dir)/include) \
+					$(foreach dir,$(LIBDIRS),-I$(dir)/include) \
+					-I$(CURDIR)/$(BUILD)
+ 
+export LIBPATHS	:=	$(foreach dir,$(LIBDIRS),-L$(dir)/lib)
+ 
+.PHONY: $(BUILD) clean
+ 
+#---------------------------------------------------------------------------------
+$(BUILD):
+	@[ -d $@ ] || mkdir -p $@
+	@make --no-print-directory -C $(BUILD) -f $(CURDIR)/Makefile
+ 
+#---------------------------------------------------------------------------------
+clean:
+	@echo clean ...
+	@rm -fr $(BUILD) $(TARGET).elf $(TARGET).nds $(TARGET).arm9 $(TARGET).ds.gba 
+ 
+ 
+#---------------------------------------------------------------------------------
+else
+ 
+DEPENDS	:=	$(OFILES:.o=.d)
+ 
+#---------------------------------------------------------------------------------
+# main targets
+#---------------------------------------------------------------------------------
+$(OUTPUT).ds.gba	: 	$(OUTPUT).nds
+$(OUTPUT).nds	: 	$(OUTPUT).arm9
+$(OUTPUT).arm9	:	$(OUTPUT).elf
+$(OUTPUT).elf	:	$(OFILES)
+ 
+#---------------------------------------------------------------------------------
+%.bin.o	:	%.bin
+#---------------------------------------------------------------------------------
+	@echo $(notdir $<)
+	@$(bin2o)
+ 
+ 
+-include $(DEPENDS)
+ 
+#---------------------------------------------------------------------------------------
+endif
+#---------------------------------------------------------------------------------------
diff --git a/arm9/Makefile b/arm9/Makefile
new file mode 100644
index 0000000..93d2484
--- /dev/null
+++ b/arm9/Makefile
@@ -0,0 +1,136 @@
+# This is a generic DS makefile, as taken from the libnds example programs.
+#
+
+#-------------------------------------------------------------------------------
+.SUFFIXES:
+#-------------------------------------------------------------------------------
+
+ifeq ($(strip $(DEVKITARM)),)
+$(error "Please set DEVKITARM in your environment. export DEVKITARM=<path to>devkitARM")
+endif
+
+include $(DEVKITARM)/ds_rules
+
+#-------------------------------------------------------------------------------
+# TARGET is the name of the output
+# BUILD is the directory where object files & intermediate files will be placed
+# SOURCES is a list of directories containing source code
+# INCLUDES is a list of directories containing extra header files
+#-------------------------------------------------------------------------------
+TARGET		:=	$(shell basename $(CURDIR))
+BUILD		:=	build
+SOURCES		:=	source gbagfx
+DATA		:=	data  
+INCLUDES	:=	include gbagfx
+
+#-------------------------------------------------------------------------------
+# options for code generation
+#-------------------------------------------------------------------------------
+ARCH	:=	-mthumb -mthumb-interwork
+
+# note: arm9tdmi isn't the correct CPU arch, but anything newer and LD
+# *insists* it has a FPU or VFP, and it won't take no for an answer!
+CFLAGS	:=	-g -Wall -O2\
+ 			-mcpu=arm9tdmi -mtune=arm9tdmi -fomit-frame-pointer\
+			-ffast-math \
+			$(ARCH)
+
+CFLAGS	+=	$(INCLUDE) -DARM9
+CXXFLAGS	:= $(CFLAGS)
+
+ASFLAGS	:=	-g $(ARCH)
+LDFLAGS	=	-specs=ds_arm9.specs -g $(ARCH) -mno-fpu -Wl,-Map,$(notdir $*.map)
+
+#-------------------------------------------------------------------------------
+# any extra libraries we wish to link with the project
+#-------------------------------------------------------------------------------
+LIBS	:= -lfat -lnds9
+ 
+ 
+#-------------------------------------------------------------------------------
+# list of directories containing libraries, this must be the top level containing
+# include and lib
+#-------------------------------------------------------------------------------
+LIBDIRS	:=	$(LIBNDS)
+ 
+#-------------------------------------------------------------------------------
+# no real need to edit anything past this point unless you need to add
+# additional rules for different file extensions
+#-------------------------------------------------------------------------------
+ifneq ($(BUILD),$(notdir $(CURDIR)))
+#-------------------------------------------------------------------------------
+ 
+export OUTPUT	:=	$(CURDIR)/$(TARGET)
+ 
+export VPATH	:=	$(foreach dir,$(SOURCES),$(CURDIR)/$(dir)) \
+					$(foreach dir,$(DATA),$(CURDIR)/$(dir))
+
+export DEPSDIR	:=	$(CURDIR)/$(BUILD)
+
+CFILES		:=	$(foreach dir,$(SOURCES),$(notdir $(wildcard $(dir)/*.c)))
+CPPFILES	:=	$(foreach dir,$(SOURCES),$(notdir $(wildcard $(dir)/*.cpp)))
+SFILES		:=	$(foreach dir,$(SOURCES),$(notdir $(wildcard $(dir)/*.s)))
+BINFILES	:=	$(foreach dir,$(DATA),$(notdir $(wildcard $(dir)/*.*)))
+ 
+#---------------------------------------------------------------------------------
+# use CXX for linking C++ projects, CC for standard C
+#---------------------------------------------------------------------------------
+ifeq ($(strip $(CPPFILES)),)
+#---------------------------------------------------------------------------------
+	export LD	:=	$(CC)
+#---------------------------------------------------------------------------------
+else
+#---------------------------------------------------------------------------------
+	export LD	:=	$(CXX)
+#---------------------------------------------------------------------------------
+endif
+#---------------------------------------------------------------------------------
+
+export OFILES	:=	$(addsuffix .o,$(BINFILES)) \
+					$(CPPFILES:.cpp=.o) $(CFILES:.c=.o) $(SFILES:.s=.o)
+ 
+export INCLUDE	:=	$(foreach dir,$(INCLUDES),-I$(CURDIR)/$(dir)) \
+					$(foreach dir,$(LIBDIRS),-I$(dir)/include) \
+					$(foreach dir,$(LIBDIRS),-I$(dir)/include) \
+					-I$(CURDIR)/$(BUILD)
+ 
+export LIBPATHS	:=	$(foreach dir,$(LIBDIRS),-L$(dir)/lib)
+ 
+.PHONY: $(BUILD) clean
+ 
+#---------------------------------------------------------------------------------
+$(BUILD):
+	@[ -d $@ ] || mkdir -p $@
+	@make --no-print-directory -C $(BUILD) -f $(CURDIR)/Makefile
+ 
+#---------------------------------------------------------------------------------
+clean:
+	@echo clean ...
+	@rm -fr $(BUILD) $(TARGET).elf $(TARGET).nds $(TARGET).arm9 $(TARGET).ds.gba 
+ 
+ 
+#---------------------------------------------------------------------------------
+else
+ 
+DEPENDS	:=	$(OFILES:.o=.d)
+ 
+#---------------------------------------------------------------------------------
+# main targets
+#---------------------------------------------------------------------------------
+$(OUTPUT).ds.gba	: 	$(OUTPUT).nds
+$(OUTPUT).nds	: 	$(OUTPUT).arm9
+$(OUTPUT).arm9	:	$(OUTPUT).elf
+$(OUTPUT).elf	:	$(OFILES)
+ 
+#---------------------------------------------------------------------------------
+%.bin.o	:	%.bin
+#---------------------------------------------------------------------------------
+	@echo $(notdir $<)
+	@$(bin2o)
+ 
+ 
+-include $(DEPENDS)
+ 
+#---------------------------------------------------------------------------------------
+endif
+#---------------------------------------------------------------------------------------
diff --git a/arm9/data/keyb.bin b/arm9/data/keyb.bin
new file mode 100644
index 0000000..4f993fa
--- /dev/null
+++ b/arm9/data/keyb.bin
diff --git a/arm9/data/maze.bin b/arm9/data/maze.bin
new file mode 100644
index 0000000..2882186
--- /dev/null
+++ b/arm9/data/maze.bin
diff --git a/arm9/data/splashimg.bin b/arm9/data/splashimg.bin
new file mode 100644
index 0000000..910f64b
--- /dev/null
+++ b/arm9/data/splashimg.bin
diff --git a/arm9/data/zx81.bin b/arm9/data/zx81.bin
new file mode 100644
index 0000000..557ddcb
--- /dev/null
+++ b/arm9/data/zx81.bin
diff --git a/arm9/include/framebuffer.h b/arm9/include/framebuffer.h
new file mode 100644
index 0000000..80a9469
--- /dev/null
+++ b/arm9/include/framebuffer.h
@@ -0,0 +1,36 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+#ifndef DS81_FRAMEBUFFER_H
+#define DS81_FRAMEBUFFER_H
+
+#define FB_RGB(r,g,b)	((RGB15(r,g,b))|0x8000)
+
+void	FB_Init(uint16 *vram);
+void	FB_Print(const char *text, int x, int y, int colour, int paper);
+void	FB_Centre(const char *text, int y, int colour, int paper);
+void	FB_HLine(int x1, int x2, int y, int colour);
+void	FB_VLine(int x, int y1, int y2, int colour);
+void	FB_Box(int x, int y, int w, int h, int colour);
+void	FB_FillBox(int x, int y, int w, int h, int colour);
+void	FB_Clear(void);
+
+#endif	/* DS81_FRAMEBUFFER_H */
diff --git a/arm9/include/gui.h b/arm9/include/gui.h
new file mode 100644
index 0000000..b9363ca
--- /dev/null
+++ b/arm9/include/gui.h
@@ -0,0 +1,27 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+#ifndef DS81_GUI_H
+#define DS81_GUI_H
+
+int	GUI_Menu(const char *opts[]);
+
+#endif	/* DS81_GUI_H */
diff --git a/arm9/include/kbd81.h b/arm9/include/kbd81.h
new file mode 100644
index 0000000..b4e3d62
--- /dev/null
+++ b/arm9/include/kbd81.h
@@ -0,0 +1,76 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+#ifndef DS81_KBD81_H
+#define DS81_KBD81_H
+
+typedef enum
+{
+    KBD_1,
+    KBD_2,
+    KBD_3,
+    KBD_4,
+    KBD_5,
+    KBD_6,
+    KBD_7,
+    KBD_8,
+    KBD_9,
+    KBD_0,
+    KBD_Q,
+    KBD_W,
+    KBD_E,
+    KBD_R,
+    KBD_T,
+    KBD_Y,
+    KBD_U,
+    KBD_I,
+    KBD_O,
+    KBD_P,
+    KBD_A,
+    KBD_S,
+    KBD_D,
+    KBD_F,
+    KBD_G,
+    KBD_H,
+    KBD_J,
+    KBD_K,
+    KBD_L,
+    KBD_NEWLINE,
+    KBD_SHIFT,
+    KBD_Z,
+    KBD_X,
+    KBD_C,
+    KBD_V,
+    KBD_B,
+    KBD_N,
+    KBD_M,
+    KBD_PERIOD,
+    KBD_SPACE
+} ZX81_Key;
+
+void		KBD_Reset(void);
+void		KBD_Display(const char *text);
+void		KBD_Scan(void);
+ZX81_Key	KBD_GetKey(void);
+void		KBD_MapKey(KEYPAD_BITS pad, ZX81_Key key);
+void		KBD_Probe(int scan);
+
+#endif	/* DS81_KBD81_H */
diff --git a/arm9/source/framebuffer.c b/arm9/source/framebuffer.c
new file mode 100644
index 0000000..26b95de
--- /dev/null
+++ b/arm9/source/framebuffer.c
@@ -0,0 +1,255 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+
+#include <nds.h>
+#include <string.h>
+
+/* ---------------------------------------- STATIC DATA
+*/
+#define WIDTH	256
+#define HEIGHT	192
+
+static uint16	*buff=0;
+
+static uint8	font[]=
+{
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x08, 0x08, 0x08, 0x08, 0x00, 0x08, 0x00,
+    0x00, 0x24, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x24, 0x7e, 0x24, 0x24, 0x7e, 0x24, 0x00,
+    0x00, 0x10, 0x7c, 0x14, 0x7c, 0x50, 0x7c, 0x10,
+    0x00, 0x46, 0x26, 0x10, 0x08, 0x64, 0x62, 0x00,
+    0x00, 0x08, 0x14, 0x08, 0x54, 0x22, 0x5c, 0x00,
+    0x00, 0x10, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x20, 0x10, 0x10, 0x10, 0x10, 0x20, 0x00,
+    0x00, 0x04, 0x08, 0x08, 0x08, 0x08, 0x04, 0x00,
+    0x00, 0x00, 0x28, 0x10, 0x7c, 0x10, 0x28, 0x00,
+    0x00, 0x00, 0x10, 0x10, 0x7c, 0x10, 0x10, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x10, 0x08,
+    0x00, 0x00, 0x00, 0x00, 0x7c, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x00,
+    0x00, 0x00, 0x40, 0x20, 0x10, 0x08, 0x04, 0x00,
+    0x00, 0x3c, 0x62, 0x52, 0x4a, 0x46, 0x3c, 0x00,
+    0x00, 0x18, 0x14, 0x10, 0x10, 0x10, 0x7c, 0x00,
+    0x00, 0x3c, 0x42, 0x40, 0x3c, 0x02, 0x7e, 0x00,
+    0x00, 0x3c, 0x42, 0x30, 0x40, 0x42, 0x3c, 0x00,
+    0x00, 0x10, 0x18, 0x14, 0x12, 0x7e, 0x10, 0x00,
+    0x00, 0x7e, 0x02, 0x3e, 0x40, 0x42, 0x3c, 0x00,
+    0x00, 0x3c, 0x02, 0x3e, 0x42, 0x42, 0x3c, 0x00,
+    0x00, 0x7e, 0x40, 0x20, 0x10, 0x08, 0x08, 0x00,
+    0x00, 0x3c, 0x42, 0x3c, 0x42, 0x42, 0x3c, 0x00,
+    0x00, 0x3c, 0x42, 0x42, 0x7c, 0x40, 0x3c, 0x00,
+    0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x08, 0x00,
+    0x00, 0x00, 0x08, 0x00, 0x00, 0x08, 0x08, 0x04,
+    0x00, 0x00, 0x20, 0x10, 0x08, 0x10, 0x20, 0x00,
+    0x00, 0x00, 0x00, 0x7c, 0x00, 0x7c, 0x00, 0x00,
+    0x00, 0x00, 0x08, 0x10, 0x20, 0x10, 0x08, 0x00,
+    0x00, 0x3c, 0x42, 0x20, 0x10, 0x00, 0x10, 0x00,
+    0x00, 0x3c, 0x52, 0x6a, 0x7a, 0x02, 0x3c, 0x00,
+    0x00, 0x3c, 0x42, 0x42, 0x7e, 0x42, 0x42, 0x00,
+    0x00, 0x3e, 0x42, 0x3e, 0x42, 0x42, 0x3e, 0x00,
+    0x00, 0x3c, 0x42, 0x02, 0x02, 0x42, 0x3c, 0x00,
+    0x00, 0x1e, 0x22, 0x42, 0x42, 0x22, 0x1e, 0x00,
+    0x00, 0x7e, 0x02, 0x3e, 0x02, 0x02, 0x7e, 0x00,
+    0x00, 0x7e, 0x02, 0x3e, 0x02, 0x02, 0x02, 0x00,
+    0x00, 0x3c, 0x42, 0x02, 0x72, 0x42, 0x3c, 0x00,
+    0x00, 0x42, 0x42, 0x7e, 0x42, 0x42, 0x42, 0x00,
+    0x00, 0x7c, 0x10, 0x10, 0x10, 0x10, 0x7c, 0x00,
+    0x00, 0x40, 0x40, 0x40, 0x42, 0x42, 0x3c, 0x00,
+    0x00, 0x22, 0x12, 0x0e, 0x12, 0x22, 0x42, 0x00,
+    0x00, 0x02, 0x02, 0x02, 0x02, 0x02, 0x7e, 0x00,
+    0x00, 0x42, 0x66, 0x5a, 0x42, 0x42, 0x42, 0x00,
+    0x00, 0x42, 0x46, 0x4a, 0x52, 0x62, 0x42, 0x00,
+    0x00, 0x3c, 0x42, 0x42, 0x42, 0x42, 0x3c, 0x00,
+    0x00, 0x3e, 0x42, 0x42, 0x3e, 0x02, 0x02, 0x00,
+    0x00, 0x3c, 0x42, 0x42, 0x4a, 0x52, 0x3c, 0x00,
+    0x00, 0x3e, 0x42, 0x42, 0x3e, 0x22, 0x42, 0x00,
+    0x00, 0x3c, 0x02, 0x3c, 0x40, 0x42, 0x3c, 0x00,
+    0x00, 0x7f, 0x08, 0x08, 0x08, 0x08, 0x08, 0x00,
+    0x00, 0x42, 0x42, 0x42, 0x42, 0x42, 0x3c, 0x00,
+    0x00, 0x42, 0x42, 0x42, 0x42, 0x24, 0x18, 0x00,
+    0x00, 0x42, 0x42, 0x42, 0x42, 0x5a, 0x24, 0x00,
+    0x00, 0x42, 0x24, 0x18, 0x18, 0x24, 0x42, 0x00,
+    0x00, 0x41, 0x22, 0x14, 0x08, 0x08, 0x08, 0x00,
+    0x00, 0x7e, 0x20, 0x10, 0x08, 0x04, 0x7e, 0x00,
+    0x00, 0x70, 0x10, 0x10, 0x10, 0x10, 0x70, 0x00,
+    0x00, 0x00, 0x02, 0x04, 0x08, 0x10, 0x20, 0x00,
+    0x00, 0x0e, 0x08, 0x08, 0x08, 0x08, 0x0e, 0x00,
+    0x00, 0x08, 0x1c, 0x2a, 0x08, 0x08, 0x08, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff,
+    0x00, 0x38, 0x44, 0x1e, 0x04, 0x04, 0x7e, 0x00,
+    0x00, 0x00, 0x1c, 0x20, 0x3c, 0x22, 0x3c, 0x00,
+    0x00, 0x04, 0x04, 0x3c, 0x44, 0x44, 0x3c, 0x00,
+    0x00, 0x00, 0x38, 0x04, 0x04, 0x04, 0x38, 0x00,
+    0x00, 0x20, 0x20, 0x3c, 0x22, 0x22, 0x3c, 0x00,
+    0x00, 0x00, 0x1c, 0x22, 0x1e, 0x02, 0x3c, 0x00,
+    0x00, 0x30, 0x08, 0x18, 0x08, 0x08, 0x08, 0x00,
+    0x00, 0x00, 0x3c, 0x22, 0x22, 0x3c, 0x20, 0x1c,
+    0x00, 0x02, 0x02, 0x1e, 0x22, 0x22, 0x22, 0x00,
+    0x00, 0x08, 0x00, 0x0c, 0x08, 0x08, 0x1c, 0x00,
+    0x00, 0x20, 0x00, 0x20, 0x20, 0x20, 0x24, 0x18,
+    0x00, 0x04, 0x14, 0x0c, 0x0c, 0x14, 0x24, 0x00,
+    0x00, 0x08, 0x08, 0x08, 0x08, 0x08, 0x30, 0x00,
+    0x00, 0x00, 0x16, 0x2a, 0x2a, 0x2a, 0x2a, 0x00,
+    0x00, 0x00, 0x1e, 0x22, 0x22, 0x22, 0x22, 0x00,
+    0x00, 0x00, 0x1c, 0x22, 0x22, 0x22, 0x1c, 0x00,
+    0x00, 0x00, 0x1e, 0x22, 0x22, 0x1e, 0x02, 0x02,
+    0x00, 0x00, 0x3c, 0x22, 0x22, 0x3c, 0x20, 0x60,
+    0x00, 0x00, 0x38, 0x04, 0x04, 0x04, 0x04, 0x00,
+    0x00, 0x00, 0x1c, 0x02, 0x1c, 0x20, 0x1e, 0x00,
+    0x00, 0x08, 0x1c, 0x08, 0x08, 0x08, 0x30, 0x00,
+    0x00, 0x00, 0x22, 0x22, 0x22, 0x22, 0x1c, 0x00,
+    0x00, 0x00, 0x22, 0x22, 0x14, 0x14, 0x08, 0x00,
+    0x00, 0x00, 0x22, 0x2a, 0x2a, 0x2a, 0x14, 0x00,
+    0x00, 0x00, 0x22, 0x14, 0x08, 0x14, 0x22, 0x00,
+    0x00, 0x00, 0x22, 0x22, 0x22, 0x3c, 0x20, 0x1c,
+    0x00, 0x00, 0x3e, 0x10, 0x08, 0x04, 0x3e, 0x00,
+    0x00, 0x70, 0x10, 0x0c, 0x10, 0x10, 0x70, 0x00,
+    0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x00,
+    0x00, 0x0e, 0x08, 0x30, 0x08, 0x08, 0x0e, 0x00,
+    0x00, 0x28, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x3c, 0x42, 0x99, 0x85, 0x85, 0x99, 0x42, 0x3c
+};
+
+/* ---------------------------------------- PUBLIC INTERFACES
+*/
+void FB_Init(uint16 *vram)
+{
+    buff=vram;
+}
+
+
+void FB_Print(const char *text, int x, int y, int colour, int paper)
+{
+    uint16 *base;
+
+    base=buff+y*WIDTH+x;
+
+    while(*text)
+    {
+	int x,y;
+    	int ch;
+
+	ch=((*text)-32)*8;
+
+	for(y=0;y<8;y++)
+	{
+	    for(x=0;x<8;x++)
+	    {
+		if (font[ch]&(1<<x))
+		{
+		    *(base+x+y*WIDTH)=colour;
+		}
+		else
+		{
+		    if (paper!=-1)
+		    {
+			*(base+x+y*WIDTH)=paper;
+		    }
+		}
+	    }
+
+	    ch++;
+	}
+
+	base+=8;
+	text++;
+    }
+}
+
+
+void FB_Centre(const char *text, int y, int colour, int paper)
+{
+    FB_Print(text,WIDTH/2-strlen(text)*4,y,colour,paper);
+}
+
+
+void FB_HLine(int x1, int x2, int y, int colour)
+{
+    uint16 *line;
+
+    line=buff+y*WIDTH+x1;
+
+    while(x1<=x2)
+    {
+    	*line++=colour;
+	x1++;
+    }
+}
+
+
+void FB_VLine(int x, int y1, int y2, int colour)
+{
+    uint16 *line;
+
+    line=buff+y1*WIDTH+x;
+
+    while(y1<=y2)
+    {
+    	*line=colour;
+	line+=WIDTH;
+	y1++;
+    }
+}
+
+
+void FB_Box(int x, int y, int w, int h, int colour)
+{
+    FB_HLine(x,x+w-1,y,colour);
+    FB_HLine(x,x+w-1,y+h-1,colour);
+    FB_VLine(x,y,y+h-1,colour);
+    FB_VLine(x+w-1,y,y+h-1,colour);
+}
+
+
+void FB_FillBox(int x, int y, int w, int h, int colour)
+{
+    int f;
+    uint16 *base;
+
+    base=buff+x+y*WIDTH;
+
+    while(h--)
+    {
+    	for(f=0;f<w;f++)
+	{
+	    *(base+f)=colour;
+	}
+
+	base+=WIDTH;
+    }
+}
+
+
+void FB_Clear(void)
+{
+    uint16 *p;
+    int f;
+
+    f=WIDTH*HEIGHT;
+    p=buff;
+
+    while(f--)
+    {
+    	*p++=0x8000;
+    }
+}
diff --git a/arm9/source/gui.c b/arm9/source/gui.c
new file mode 100644
index 0000000..45b0817
--- /dev/null
+++ b/arm9/source/gui.c
@@ -0,0 +1,118 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+
+#include <nds.h>
+#include <string.h>
+
+#include "framebuffer.h"
+
+
+/* ---------------------------------------- PUBLIC INTERFACES
+*/
+int GUI_Menu(const char *opts[])
+{
+    int x,y;
+    int h;
+    int w;
+    int no;
+    int sel;
+    int f;
+    bool done;
+    bool defer;
+
+    w=0;
+    h=0;
+    sel=0;
+    done=false;
+    defer=false;
+
+    for(no=0;opts[no];no++)
+    {
+    	h+=16;
+
+	if (strlen(opts[no])>w)
+	{
+	    w=strlen(opts[no]);
+	}
+    }
+
+    w=w*8+16;
+
+    x=SCREEN_WIDTH/2-w/2;
+    y=SCREEN_HEIGHT/2-h/2;
+
+    while(!done)
+    {
+	uint32 key=0;
+
+	FB_FillBox(x,y,w,h,FB_RGB(0,0,0));
+	FB_Box(x,y,w,h,FB_RGB(31,31,31));
+	FB_FillBox(x+1,y+sel*16+1,w-2,14,FB_RGB(8,8,31));
+
+    	for(f=0;f<no;f++)
+	{
+	    FB_Centre(opts[f],y+4+f*16,FB_RGB(31,31,31),-1);
+	}
+
+	do
+	{
+	    swiWaitForVBlank();
+	} while(!defer && !(key=keysDownRepeat()));
+
+	if (defer)
+	{
+	    do
+	    {
+	    	swiWaitForVBlank();
+	    } while (keysHeld()&KEY_TOUCH);
+	    done=true;
+	}
+	else
+	{
+	    if (key & (KEY_A|KEY_B|KEY_X|KEY_Y))
+	    {
+		done=true;
+	    }
+	    else if ((key & KEY_UP) && sel)
+	    {
+		sel--;
+	    }
+	    else if ((key & KEY_DOWN) && sel<no-1)
+	    {
+		sel++;
+	    }
+	    else if (key & KEY_TOUCH)
+	    {
+		touchPosition tp=touchReadXY();
+
+		if (tp.px>=x && tp.px<(w+w) && tp.py>=y && tp.py<(y+h))
+		{
+		    defer=true;
+		    sel=(tp.py-y)/16;
+		}
+	    }
+	}
+    }
+
+    return sel;
+}
+
diff --git a/arm9/source/main.c b/arm9/source/main.c
new file mode 100644
index 0000000..a5f5035
--- /dev/null
+++ b/arm9/source/main.c
@@ -0,0 +1,137 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <nds.h>
+
+#include "framebuffer.h"
+#include "gui.h"
+
+#include "splashimg_bin.h"
+
+/* ---------------------------------------- STATIC DATA
+*/
+
+
+/* ---------------------------------------- DISPLAY FUNCS
+*/
+static void VBlankFunc(void)
+{
+    scanKeys();
+}
+
+static void Splash(void)
+{
+    static const char *text[]=
+    {
+    	"DS81 \177 2006 Ian C",
+	" ",
+	"ZX81 ROM \177 1981",
+	"Nine Tiles Networks LTD",
+	" ",
+	"3D MONSTER MAZE \177 1983",
+	"Malcom E. Evans",
+	" ",
+	"PRESS A TO CONTINUE",
+	" ",
+	" ",
+	"http://www.noddybox.co.uk/",
+	NULL
+    };
+
+    sImage img;
+    int f;
+
+    loadPCX(splashimg_bin,&img);
+    image8to16(&img);
+    dmaCopy(img.data8,BG_GFX,SCREEN_WIDTH*SCREEN_HEIGHT*2);
+
+    FB_Clear();
+
+    for(f=0;f<SCREEN_HEIGHT;f++)
+    {
+	FB_HLine(0,SCREEN_WIDTH-1,f,FB_RGB(f/8,0,0));
+    }
+
+    FB_Box(0,0,SCREEN_WIDTH,SCREEN_HEIGHT,FB_RGB(31,31,31));
+
+    for(f=0;text[f];f++)
+    {
+	FB_Centre(text[f],40+f*8,FB_RGB(31,31,31),-1);
+    }
+
+    while(!(keysDown() & KEY_A))
+    {
+	swiWaitForVBlank();
+    }
+}
+
+
+/* ---------------------------------------- MAIN
+*/
+int main(int argc, char *argv[])
+{
+    powerON(POWER_ALL_2D);
+
+    videoSetMode(MODE_5_2D | DISPLAY_BG2_ACTIVE);
+
+    vramSetBankA(VRAM_A_MAIN_BG_0x6000000);
+    BG2_CR = BG_BMP16_256x256;
+    BG2_XDX = 0x100;
+    BG2_XDY = 0;
+    BG2_YDX = 0;
+    BG2_YDY = 0x100;
+    BG2_CX = 0;
+    BG2_CY = 0;
+
+    videoSetModeSub(MODE_5_2D | DISPLAY_BG2_ACTIVE);
+
+    vramSetBankC(VRAM_C_SUB_BG_0x6200000);
+    SUB_BG2_CR = BG_BMP16_256x256;
+    SUB_BG2_XDX = 0x100;
+    SUB_BG2_XDY = 0;
+    SUB_BG2_YDX = 0;
+    SUB_BG2_YDY = 0x100;
+    SUB_BG2_CX = 0;
+    SUB_BG2_CY = 0;
+
+    irqInit();
+    irqSet(IRQ_VBLANK,VBlankFunc);
+
+    keysSetRepeat(30,15);
+
+    FB_Init(BG_GFX_SUB);
+
+    Splash();
+
+    while(1)
+    {
+	static const char *menu[]={"Option #1","A longer option","Short","Wibble Sticks!",NULL};
+	char buff[32];
+
+	sprintf(buff,"sel=%d",GUI_Menu(menu));
+	FB_Centre(buff,SCREEN_HEIGHT-10,FB_RGB(31,31,31),FB_RGB(0,0,15));
+    }
+
+    return 0;
+}
diff --git a/data/keyb.bin b/data/keyb.bin
new file mode 100644
index 0000000..4f993fa
--- /dev/null
+++ b/data/keyb.bin
diff --git a/data/maze.bin b/data/maze.bin
new file mode 100644
index 0000000..2882186
--- /dev/null
+++ b/data/maze.bin
diff --git a/data/splashimg.bin b/data/splashimg.bin
new file mode 100644
index 0000000..910f64b
--- /dev/null
+++ b/data/splashimg.bin
diff --git a/data/zx81.bin b/data/zx81.bin
new file mode 100644
index 0000000..557ddcb
--- /dev/null
+++ b/data/zx81.bin
diff --git a/include/framebuffer.h b/include/framebuffer.h
new file mode 100644
index 0000000..80a9469
--- /dev/null
+++ b/include/framebuffer.h
@@ -0,0 +1,36 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+#ifndef DS81_FRAMEBUFFER_H
+#define DS81_FRAMEBUFFER_H
+
+#define FB_RGB(r,g,b)	((RGB15(r,g,b))|0x8000)
+
+void	FB_Init(uint16 *vram);
+void	FB_Print(const char *text, int x, int y, int colour, int paper);
+void	FB_Centre(const char *text, int y, int colour, int paper);
+void	FB_HLine(int x1, int x2, int y, int colour);
+void	FB_VLine(int x, int y1, int y2, int colour);
+void	FB_Box(int x, int y, int w, int h, int colour);
+void	FB_FillBox(int x, int y, int w, int h, int colour);
+void	FB_Clear(void);
+
+#endif	/* DS81_FRAMEBUFFER_H */
diff --git a/include/gui.h b/include/gui.h
new file mode 100644
index 0000000..b9363ca
--- /dev/null
+++ b/include/gui.h
@@ -0,0 +1,27 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+#ifndef DS81_GUI_H
+#define DS81_GUI_H
+
+int	GUI_Menu(const char *opts[]);
+
+#endif	/* DS81_GUI_H */
diff --git a/include/kbd81.h b/include/kbd81.h
new file mode 100644
index 0000000..b4e3d62
--- /dev/null
+++ b/include/kbd81.h
@@ -0,0 +1,76 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+#ifndef DS81_KBD81_H
+#define DS81_KBD81_H
+
+typedef enum
+{
+    KBD_1,
+    KBD_2,
+    KBD_3,
+    KBD_4,
+    KBD_5,
+    KBD_6,
+    KBD_7,
+    KBD_8,
+    KBD_9,
+    KBD_0,
+    KBD_Q,
+    KBD_W,
+    KBD_E,
+    KBD_R,
+    KBD_T,
+    KBD_Y,
+    KBD_U,
+    KBD_I,
+    KBD_O,
+    KBD_P,
+    KBD_A,
+    KBD_S,
+    KBD_D,
+    KBD_F,
+    KBD_G,
+    KBD_H,
+    KBD_J,
+    KBD_K,
+    KBD_L,
+    KBD_NEWLINE,
+    KBD_SHIFT,
+    KBD_Z,
+    KBD_X,
+    KBD_C,
+    KBD_V,
+    KBD_B,
+    KBD_N,
+    KBD_M,
+    KBD_PERIOD,
+    KBD_SPACE
+} ZX81_Key;
+
+void		KBD_Reset(void);
+void		KBD_Display(const char *text);
+void		KBD_Scan(void);
+ZX81_Key	KBD_GetKey(void);
+void		KBD_MapKey(KEYPAD_BITS pad, ZX81_Key key);
+void		KBD_Probe(int scan);
+
+#endif	/* DS81_KBD81_H */
diff --git a/source/framebuffer.c b/source/framebuffer.c
new file mode 100644
index 0000000..26b95de
--- /dev/null
+++ b/source/framebuffer.c
@@ -0,0 +1,255 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+
+#include <nds.h>
+#include <string.h>
+
+/* ---------------------------------------- STATIC DATA
+*/
+#define WIDTH	256
+#define HEIGHT	192
+
+static uint16	*buff=0;
+
+static uint8	font[]=
+{
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x08, 0x08, 0x08, 0x08, 0x00, 0x08, 0x00,
+    0x00, 0x24, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x24, 0x7e, 0x24, 0x24, 0x7e, 0x24, 0x00,
+    0x00, 0x10, 0x7c, 0x14, 0x7c, 0x50, 0x7c, 0x10,
+    0x00, 0x46, 0x26, 0x10, 0x08, 0x64, 0x62, 0x00,
+    0x00, 0x08, 0x14, 0x08, 0x54, 0x22, 0x5c, 0x00,
+    0x00, 0x10, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x20, 0x10, 0x10, 0x10, 0x10, 0x20, 0x00,
+    0x00, 0x04, 0x08, 0x08, 0x08, 0x08, 0x04, 0x00,
+    0x00, 0x00, 0x28, 0x10, 0x7c, 0x10, 0x28, 0x00,
+    0x00, 0x00, 0x10, 0x10, 0x7c, 0x10, 0x10, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x10, 0x08,
+    0x00, 0x00, 0x00, 0x00, 0x7c, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x18, 0x18, 0x00,
+    0x00, 0x00, 0x40, 0x20, 0x10, 0x08, 0x04, 0x00,
+    0x00, 0x3c, 0x62, 0x52, 0x4a, 0x46, 0x3c, 0x00,
+    0x00, 0x18, 0x14, 0x10, 0x10, 0x10, 0x7c, 0x00,
+    0x00, 0x3c, 0x42, 0x40, 0x3c, 0x02, 0x7e, 0x00,
+    0x00, 0x3c, 0x42, 0x30, 0x40, 0x42, 0x3c, 0x00,
+    0x00, 0x10, 0x18, 0x14, 0x12, 0x7e, 0x10, 0x00,
+    0x00, 0x7e, 0x02, 0x3e, 0x40, 0x42, 0x3c, 0x00,
+    0x00, 0x3c, 0x02, 0x3e, 0x42, 0x42, 0x3c, 0x00,
+    0x00, 0x7e, 0x40, 0x20, 0x10, 0x08, 0x08, 0x00,
+    0x00, 0x3c, 0x42, 0x3c, 0x42, 0x42, 0x3c, 0x00,
+    0x00, 0x3c, 0x42, 0x42, 0x7c, 0x40, 0x3c, 0x00,
+    0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x08, 0x00,
+    0x00, 0x00, 0x08, 0x00, 0x00, 0x08, 0x08, 0x04,
+    0x00, 0x00, 0x20, 0x10, 0x08, 0x10, 0x20, 0x00,
+    0x00, 0x00, 0x00, 0x7c, 0x00, 0x7c, 0x00, 0x00,
+    0x00, 0x00, 0x08, 0x10, 0x20, 0x10, 0x08, 0x00,
+    0x00, 0x3c, 0x42, 0x20, 0x10, 0x00, 0x10, 0x00,
+    0x00, 0x3c, 0x52, 0x6a, 0x7a, 0x02, 0x3c, 0x00,
+    0x00, 0x3c, 0x42, 0x42, 0x7e, 0x42, 0x42, 0x00,
+    0x00, 0x3e, 0x42, 0x3e, 0x42, 0x42, 0x3e, 0x00,
+    0x00, 0x3c, 0x42, 0x02, 0x02, 0x42, 0x3c, 0x00,
+    0x00, 0x1e, 0x22, 0x42, 0x42, 0x22, 0x1e, 0x00,
+    0x00, 0x7e, 0x02, 0x3e, 0x02, 0x02, 0x7e, 0x00,
+    0x00, 0x7e, 0x02, 0x3e, 0x02, 0x02, 0x02, 0x00,
+    0x00, 0x3c, 0x42, 0x02, 0x72, 0x42, 0x3c, 0x00,
+    0x00, 0x42, 0x42, 0x7e, 0x42, 0x42, 0x42, 0x00,
+    0x00, 0x7c, 0x10, 0x10, 0x10, 0x10, 0x7c, 0x00,
+    0x00, 0x40, 0x40, 0x40, 0x42, 0x42, 0x3c, 0x00,
+    0x00, 0x22, 0x12, 0x0e, 0x12, 0x22, 0x42, 0x00,
+    0x00, 0x02, 0x02, 0x02, 0x02, 0x02, 0x7e, 0x00,
+    0x00, 0x42, 0x66, 0x5a, 0x42, 0x42, 0x42, 0x00,
+    0x00, 0x42, 0x46, 0x4a, 0x52, 0x62, 0x42, 0x00,
+    0x00, 0x3c, 0x42, 0x42, 0x42, 0x42, 0x3c, 0x00,
+    0x00, 0x3e, 0x42, 0x42, 0x3e, 0x02, 0x02, 0x00,
+    0x00, 0x3c, 0x42, 0x42, 0x4a, 0x52, 0x3c, 0x00,
+    0x00, 0x3e, 0x42, 0x42, 0x3e, 0x22, 0x42, 0x00,
+    0x00, 0x3c, 0x02, 0x3c, 0x40, 0x42, 0x3c, 0x00,
+    0x00, 0x7f, 0x08, 0x08, 0x08, 0x08, 0x08, 0x00,
+    0x00, 0x42, 0x42, 0x42, 0x42, 0x42, 0x3c, 0x00,
+    0x00, 0x42, 0x42, 0x42, 0x42, 0x24, 0x18, 0x00,
+    0x00, 0x42, 0x42, 0x42, 0x42, 0x5a, 0x24, 0x00,
+    0x00, 0x42, 0x24, 0x18, 0x18, 0x24, 0x42, 0x00,
+    0x00, 0x41, 0x22, 0x14, 0x08, 0x08, 0x08, 0x00,
+    0x00, 0x7e, 0x20, 0x10, 0x08, 0x04, 0x7e, 0x00,
+    0x00, 0x70, 0x10, 0x10, 0x10, 0x10, 0x70, 0x00,
+    0x00, 0x00, 0x02, 0x04, 0x08, 0x10, 0x20, 0x00,
+    0x00, 0x0e, 0x08, 0x08, 0x08, 0x08, 0x0e, 0x00,
+    0x00, 0x08, 0x1c, 0x2a, 0x08, 0x08, 0x08, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff,
+    0x00, 0x38, 0x44, 0x1e, 0x04, 0x04, 0x7e, 0x00,
+    0x00, 0x00, 0x1c, 0x20, 0x3c, 0x22, 0x3c, 0x00,
+    0x00, 0x04, 0x04, 0x3c, 0x44, 0x44, 0x3c, 0x00,
+    0x00, 0x00, 0x38, 0x04, 0x04, 0x04, 0x38, 0x00,
+    0x00, 0x20, 0x20, 0x3c, 0x22, 0x22, 0x3c, 0x00,
+    0x00, 0x00, 0x1c, 0x22, 0x1e, 0x02, 0x3c, 0x00,
+    0x00, 0x30, 0x08, 0x18, 0x08, 0x08, 0x08, 0x00,
+    0x00, 0x00, 0x3c, 0x22, 0x22, 0x3c, 0x20, 0x1c,
+    0x00, 0x02, 0x02, 0x1e, 0x22, 0x22, 0x22, 0x00,
+    0x00, 0x08, 0x00, 0x0c, 0x08, 0x08, 0x1c, 0x00,
+    0x00, 0x20, 0x00, 0x20, 0x20, 0x20, 0x24, 0x18,
+    0x00, 0x04, 0x14, 0x0c, 0x0c, 0x14, 0x24, 0x00,
+    0x00, 0x08, 0x08, 0x08, 0x08, 0x08, 0x30, 0x00,
+    0x00, 0x00, 0x16, 0x2a, 0x2a, 0x2a, 0x2a, 0x00,
+    0x00, 0x00, 0x1e, 0x22, 0x22, 0x22, 0x22, 0x00,
+    0x00, 0x00, 0x1c, 0x22, 0x22, 0x22, 0x1c, 0x00,
+    0x00, 0x00, 0x1e, 0x22, 0x22, 0x1e, 0x02, 0x02,
+    0x00, 0x00, 0x3c, 0x22, 0x22, 0x3c, 0x20, 0x60,
+    0x00, 0x00, 0x38, 0x04, 0x04, 0x04, 0x04, 0x00,
+    0x00, 0x00, 0x1c, 0x02, 0x1c, 0x20, 0x1e, 0x00,
+    0x00, 0x08, 0x1c, 0x08, 0x08, 0x08, 0x30, 0x00,
+    0x00, 0x00, 0x22, 0x22, 0x22, 0x22, 0x1c, 0x00,
+    0x00, 0x00, 0x22, 0x22, 0x14, 0x14, 0x08, 0x00,
+    0x00, 0x00, 0x22, 0x2a, 0x2a, 0x2a, 0x14, 0x00,
+    0x00, 0x00, 0x22, 0x14, 0x08, 0x14, 0x22, 0x00,
+    0x00, 0x00, 0x22, 0x22, 0x22, 0x3c, 0x20, 0x1c,
+    0x00, 0x00, 0x3e, 0x10, 0x08, 0x04, 0x3e, 0x00,
+    0x00, 0x70, 0x10, 0x0c, 0x10, 0x10, 0x70, 0x00,
+    0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x00,
+    0x00, 0x0e, 0x08, 0x30, 0x08, 0x08, 0x0e, 0x00,
+    0x00, 0x28, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x3c, 0x42, 0x99, 0x85, 0x85, 0x99, 0x42, 0x3c
+};
+
+/* ---------------------------------------- PUBLIC INTERFACES
+*/
+void FB_Init(uint16 *vram)
+{
+    buff=vram;
+}
+
+
+void FB_Print(const char *text, int x, int y, int colour, int paper)
+{
+    uint16 *base;
+
+    base=buff+y*WIDTH+x;
+
+    while(*text)
+    {
+	int x,y;
+    	int ch;
+
+	ch=((*text)-32)*8;
+
+	for(y=0;y<8;y++)
+	{
+	    for(x=0;x<8;x++)
+	    {
+		if (font[ch]&(1<<x))
+		{
+		    *(base+x+y*WIDTH)=colour;
+		}
+		else
+		{
+		    if (paper!=-1)
+		    {
+			*(base+x+y*WIDTH)=paper;
+		    }
+		}
+	    }
+
+	    ch++;
+	}
+
+	base+=8;
+	text++;
+    }
+}
+
+
+void FB_Centre(const char *text, int y, int colour, int paper)
+{
+    FB_Print(text,WIDTH/2-strlen(text)*4,y,colour,paper);
+}
+
+
+void FB_HLine(int x1, int x2, int y, int colour)
+{
+    uint16 *line;
+
+    line=buff+y*WIDTH+x1;
+
+    while(x1<=x2)
+    {
+    	*line++=colour;
+	x1++;
+    }
+}
+
+
+void FB_VLine(int x, int y1, int y2, int colour)
+{
+    uint16 *line;
+
+    line=buff+y1*WIDTH+x;
+
+    while(y1<=y2)
+    {
+    	*line=colour;
+	line+=WIDTH;
+	y1++;
+    }
+}
+
+
+void FB_Box(int x, int y, int w, int h, int colour)
+{
+    FB_HLine(x,x+w-1,y,colour);
+    FB_HLine(x,x+w-1,y+h-1,colour);
+    FB_VLine(x,y,y+h-1,colour);
+    FB_VLine(x+w-1,y,y+h-1,colour);
+}
+
+
+void FB_FillBox(int x, int y, int w, int h, int colour)
+{
+    int f;
+    uint16 *base;
+
+    base=buff+x+y*WIDTH;
+
+    while(h--)
+    {
+    	for(f=0;f<w;f++)
+	{
+	    *(base+f)=colour;
+	}
+
+	base+=WIDTH;
+    }
+}
+
+
+void FB_Clear(void)
+{
+    uint16 *p;
+    int f;
+
+    f=WIDTH*HEIGHT;
+    p=buff;
+
+    while(f--)
+    {
+    	*p++=0x8000;
+    }
+}
diff --git a/source/gui.c b/source/gui.c
new file mode 100644
index 0000000..45b0817
--- /dev/null
+++ b/source/gui.c
@@ -0,0 +1,118 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+
+#include <nds.h>
+#include <string.h>
+
+#include "framebuffer.h"
+
+
+/* ---------------------------------------- PUBLIC INTERFACES
+*/
+int GUI_Menu(const char *opts[])
+{
+    int x,y;
+    int h;
+    int w;
+    int no;
+    int sel;
+    int f;
+    bool done;
+    bool defer;
+
+    w=0;
+    h=0;
+    sel=0;
+    done=false;
+    defer=false;
+
+    for(no=0;opts[no];no++)
+    {
+    	h+=16;
+
+	if (strlen(opts[no])>w)
+	{
+	    w=strlen(opts[no]);
+	}
+    }
+
+    w=w*8+16;
+
+    x=SCREEN_WIDTH/2-w/2;
+    y=SCREEN_HEIGHT/2-h/2;
+
+    while(!done)
+    {
+	uint32 key=0;
+
+	FB_FillBox(x,y,w,h,FB_RGB(0,0,0));
+	FB_Box(x,y,w,h,FB_RGB(31,31,31));
+	FB_FillBox(x+1,y+sel*16+1,w-2,14,FB_RGB(8,8,31));
+
+    	for(f=0;f<no;f++)
+	{
+	    FB_Centre(opts[f],y+4+f*16,FB_RGB(31,31,31),-1);
+	}
+
+	do
+	{
+	    swiWaitForVBlank();
+	} while(!defer && !(key=keysDownRepeat()));
+
+	if (defer)
+	{
+	    do
+	    {
+	    	swiWaitForVBlank();
+	    } while (keysHeld()&KEY_TOUCH);
+	    done=true;
+	}
+	else
+	{
+	    if (key & (KEY_A|KEY_B|KEY_X|KEY_Y))
+	    {
+		done=true;
+	    }
+	    else if ((key & KEY_UP) && sel)
+	    {
+		sel--;
+	    }
+	    else if ((key & KEY_DOWN) && sel<no-1)
+	    {
+		sel++;
+	    }
+	    else if (key & KEY_TOUCH)
+	    {
+		touchPosition tp=touchReadXY();
+
+		if (tp.px>=x && tp.px<(w+w) && tp.py>=y && tp.py<(y+h))
+		{
+		    defer=true;
+		    sel=(tp.py-y)/16;
+		}
+	    }
+	}
+    }
+
+    return sel;
+}
+
diff --git a/source/main.c b/source/main.c
new file mode 100644
index 0000000..a5f5035
--- /dev/null
+++ b/source/main.c
@@ -0,0 +1,137 @@
+/*
+   ds81 - Nintendo DS ZX81 emulator.
+
+   Copyright (C) 2006  Ian Cowburn
+   
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+  
+   $Id$
+*/
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <nds.h>
+
+#include "framebuffer.h"
+#include "gui.h"
+
+#include "splashimg_bin.h"
+
+/* ---------------------------------------- STATIC DATA
+*/
+
+
+/* ---------------------------------------- DISPLAY FUNCS
+*/
+static void VBlankFunc(void)
+{
+    scanKeys();
+}
+
+static void Splash(void)
+{
+    static const char *text[]=
+    {
+    	"DS81 \177 2006 Ian C",
+	" ",
+	"ZX81 ROM \177 1981",
+	"Nine Tiles Networks LTD",
+	" ",
+	"3D MONSTER MAZE \177 1983",
+	"Malcom E. Evans",
+	" ",
+	"PRESS A TO CONTINUE",
+	" ",
+	" ",
+	"http://www.noddybox.co.uk/",
+	NULL
+    };
+
+    sImage img;
+    int f;
+
+    loadPCX(splashimg_bin,&img);
+    image8to16(&img);
+    dmaCopy(img.data8,BG_GFX,SCREEN_WIDTH*SCREEN_HEIGHT*2);
+
+    FB_Clear();
+
+    for(f=0;f<SCREEN_HEIGHT;f++)
+    {
+	FB_HLine(0,SCREEN_WIDTH-1,f,FB_RGB(f/8,0,0));
+    }
+
+    FB_Box(0,0,SCREEN_WIDTH,SCREEN_HEIGHT,FB_RGB(31,31,31));
+
+    for(f=0;text[f];f++)
+    {
+	FB_Centre(text[f],40+f*8,FB_RGB(31,31,31),-1);
+    }
+
+    while(!(keysDown() & KEY_A))
+    {
+	swiWaitForVBlank();
+    }
+}
+
+
+/* ---------------------------------------- MAIN
+*/
+int main(int argc, char *argv[])
+{
+    powerON(POWER_ALL_2D);
+
+    videoSetMode(MODE_5_2D | DISPLAY_BG2_ACTIVE);
+
+    vramSetBankA(VRAM_A_MAIN_BG_0x6000000);
+    BG2_CR = BG_BMP16_256x256;
+    BG2_XDX = 0x100;
+    BG2_XDY = 0;
+    BG2_YDX = 0;
+    BG2_YDY = 0x100;
+    BG2_CX = 0;
+    BG2_CY = 0;
+
+    videoSetModeSub(MODE_5_2D | DISPLAY_BG2_ACTIVE);
+
+    vramSetBankC(VRAM_C_SUB_BG_0x6200000);
+    SUB_BG2_CR = BG_BMP16_256x256;
+    SUB_BG2_XDX = 0x100;
+    SUB_BG2_XDY = 0;
+    SUB_BG2_YDX = 0;
+    SUB_BG2_YDY = 0x100;
+    SUB_BG2_CX = 0;
+    SUB_BG2_CY = 0;
+
+    irqInit();
+    irqSet(IRQ_VBLANK,VBlankFunc);
+
+    keysSetRepeat(30,15);
+
+    FB_Init(BG_GFX_SUB);
+
+    Splash();
+
+    while(1)
+    {
+	static const char *menu[]={"Option #1","A longer option","Short","Wibble Sticks!",NULL};
+	char buff[32];
+
+	sprintf(buff,"sel=%d",GUI_Menu(menu));
+	FB_Centre(buff,SCREEN_HEIGHT-10,FB_RGB(31,31,31),FB_RGB(0,0,15));
+    }
+
+    return 0;
+}