Development checkin

11 files changed, 1309 insertions, 192 deletions

diff --git a/Makefile b/Makefile
index d309ea7..09d32ab 100644
--- a/Makefile
+++ b/Makefile
@@ -18,7 +18,7 @@
 # 
 # -------------------------------------------------------------------------
 # 
-# $Id: Makefile,v 1.12 2006-08-28 22:40:44 ianc Exp $
+# $Id: Makefile,v 1.13 2006-08-30 22:24:41 ianc Exp $
 # 
 
 #
@@ -70,7 +70,8 @@ SOURCE	=	z80.c \
 		support.c \
 		callbacks.c \
 		interface.c \
-		gtkutil.c
+		gtkutil.c \
+		gemma.c
 
 BASE_O	=	z80.o \
 		z80_decode.o \
@@ -83,7 +84,8 @@ GEMMA_O	=	main.o \
 		support.o \
 		callbacks.o \
 		interface.o \
-		gtkutil.o
+		gtkutil.o \
+		gemma.o
 
 all: $(TARGETS)
 
@@ -91,7 +93,7 @@ emma: $(BASE_O) $(EMMA_O)
 	cc -o emma $(BASE_O) $(EMMA_O) $(LIBS)
 
 gemma: $(BASE_O) $(GEMMA_O)
-	cc -o gemma $(GBASE_O) $(GEMMA_O) `pkg-config --libs gtk+-2.0`
+	cc -o gemma $(BASE_O) $(GEMMA_O) `pkg-config --libs gtk+-2.0`
 
 tests: emucpm.hex zexdoc.hex zexall.hex
 
diff --git a/callbacks.c b/callbacks.c
index 019fde9..a0a7a1a 100644
--- a/callbacks.c
+++ b/callbacks.c
@@ -3,8 +3,82 @@
 #endif
 
 #include <gtk/gtk.h>
+#include <limits.h>
 
 #include "callbacks.h"
 #include "interface.h"
 #include "support.h"
 
+#include "gtkutil.h"
+#include "gemma.h"
+
+
+void CloseApplication(GtkObject *object, gpointer user_data)
+{
+    gtk_main_quit();
+}
+
+
+void OnRun(GtkButton *button, gpointer user_data)
+{
+    GEMMA_Run();
+}
+
+
+void OnStep(GtkButton *button, gpointer user_data)
+{
+    GEMMA_Step();
+}
+
+
+void OnStepOver(GtkButton *button, gpointer user_data)
+{
+    GEMMA_StepOver();
+}
+
+
+void OnStop(GtkButton *button, gpointer user_data)
+{
+    GEMMA_Stop();
+}
+
+
+void OnLoadHEX(GtkButton *button, gpointer user_data)
+{
+    static char path[PATH_MAX]={0};
+
+    if (DialogFSelect("Select INTEL HEX File to load",path))
+    {
+    	GEMMA_LoadHEX(path);
+    }
+}
+
+
+void OnLoadLabels(GtkButton *button, gpointer user_data)
+{
+    static char path[PATH_MAX]={0};
+
+    if (DialogFSelect("Select Label File to load",path))
+    {
+    	GEMMA_LoadLabels(path);
+    }
+}
+
+
+void OnRunUntil(GtkButton *button, gpointer user_data)
+{
+    DialogOK("Not yet implemented");
+}
+
+
+void OnQuit(GtkButton *button, gpointer user_data)
+{
+    gtk_main_quit();
+}
+
+
+void OnMemoryViewChoice(GtkComboBox *combobox, gpointer user_data)
+{
+    GEMMA_UpdateDisplay(UPDATE_MEM_VIEW);
+}
+
diff --git a/callbacks.h b/callbacks.h
index 6fefc7c..f3a05f5 100644
--- a/callbacks.h
+++ b/callbacks.h
@@ -1,2 +1,42 @@
 #include <gtk/gtk.h>
 
+
+void
+CloseApplication                       (GtkObject       *object,
+                                        gpointer         user_data);
+
+void
+OnRun                                  (GtkButton       *button,
+                                        gpointer         user_data);
+
+void
+OnStep                                 (GtkButton       *button,
+                                        gpointer         user_data);
+
+void
+OnStepOver                             (GtkButton       *button,
+                                        gpointer         user_data);
+
+void
+OnStop                                 (GtkButton       *button,
+                                        gpointer         user_data);
+
+void
+OnLoadHEX                              (GtkButton       *button,
+                                        gpointer         user_data);
+
+void
+OnLoadLabels                           (GtkButton       *button,
+                                        gpointer         user_data);
+
+void
+OnRunUntil                             (GtkButton       *button,
+                                        gpointer         user_data);
+
+void
+OnQuit                                 (GtkButton       *button,
+                                        gpointer         user_data);
+
+void
+OnMemoryViewChoice                     (GtkComboBox     *combobox,
+                                        gpointer         user_data);
diff --git a/gemma.c b/gemma.c
new file mode 100644
index 0000000..015362b
--- /dev/null
+++ b/gemma.c
@@ -0,0 +1,837 @@
+/*
+
+    GEMMA - Z80 testbed
+
+    Copyright (C) 2006  Ian Cowburn (ianc@noddybox.demon.co.uk)
+
+    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
+
+    -------------------------------------------------------------------------
+
+*/
+static const char id[]="$Id$";
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <signal.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "gemma.h"
+#include "expr.h"
+#include "gtkutil.h"
+#include "support.h"
+
+#define HI(w)   (((w)&0xff00)>>8)
+#define LO(w)   ((w)&0xff)
+#define MK(h,l) (((Z80Word)(h))<<8|(l))
+
+/* ---------------------------------------- GLOBALS
+*/
+static Z80		*z80;
+static Z80Byte		mem[0x10000];
+static int		memctl[256];
+
+static sig_atomic_t	stop=FALSE;
+
+static Z80Label		*label=NULL;
+
+static GtkWidget	*run_button;
+static GtkWidget	*step_button;
+static GtkWidget	*step_over_button;
+static GtkWidget	*stop_button;
+static GtkWidget	*run_until_button;
+
+static GtkWidget	*top_window;
+static GtkWidget	*regview;
+static GtkWidget	*memview;
+static GtkWidget	*viewreg;
+static GtkWidget	*logview;
+static GtkWidget	*assemview;
+
+#define RUNNING(t)	gtk_widget_set_sensitive(run_button,!t); \
+			gtk_widget_set_sensitive(step_button,!t); \
+			gtk_widget_set_sensitive(step_over_button,!t); \
+			gtk_widget_set_sensitive(run_until_button,!t); \
+			gtk_widget_set_sensitive(stop_button,t);
+
+
+/* ---------------------------------------- PROTOS
+*/
+static void		Log(const char *format, ...);
+static Z80Word		Address(const char *p);
+static void		*Malloc(size_t len);
+static void		*Realloc(void *p, size_t len);
+
+
+/* ---------------------------------------- DYNAMIC STRINGS
+*/
+
+typedef struct
+{
+    size_t	len;
+    char	*text;
+} *DString;
+
+
+#define BLOCKSIZE	512
+
+
+DString DSInit(void)
+{
+    DString ds;
+
+    ds=Malloc(sizeof *ds);
+
+    ds->len=0;
+    ds->text=Malloc(BLOCKSIZE);
+    ds->text[0]=0;
+
+    return ds;
+}
+
+
+void DSFree(DString ds)
+{
+    if (ds)
+    {
+	free(ds->text);
+	free(ds);
+    }
+}
+
+
+DString DSAddChar(DString to, char c)
+{
+    if (((to->len+2)%BLOCKSIZE)==0)
+    {
+    	to->text=Realloc(to->text,(((to->len+2)/BLOCKSIZE)+1)*BLOCKSIZE);
+    }
+
+    to->text[to->len++]=c;
+    to->text[to->len]=0;
+
+    return to;
+}
+
+
+DString DSAdd(DString to, const char *from)
+{
+    to->len+=strlen(from);
+    to->text=Realloc(to->text,(((to->len+1)/BLOCKSIZE)+1)*BLOCKSIZE);
+
+    strcat(to->text,from);
+
+    return to;
+}
+
+
+/* ---------------------------------------- PRIVATE FUNCTIONS
+*/
+static void Log(const char *format, ...)
+{
+    static char buff[4096];
+    va_list va;
+
+    va_start(va,format);
+    vsprintf(buff,format,va);
+    va_end(va);
+
+    AppendText(logview,buff);
+}
+
+
+static int StrEq(const char *a, const char *b)
+{
+    while(*a && *b && tolower(*a)==tolower(*b))
+    {
+    	a++;
+	b++;
+    }
+
+    if (*a || *b)
+	return FALSE;
+    else
+	return TRUE;
+}
+
+
+static int Expand(void *client, const char *p, long *res)
+{
+    Z80State s;
+    int ok=TRUE;
+
+    Z80GetState(z80,&s);
+
+    if (StrEq(p,"AF"))
+    	*res=s.AF;
+    else if (StrEq(p,"BC"))
+    	*res=s.BC;
+    else if (StrEq(p,"DE"))
+    	*res=s.DE;
+    else if (StrEq(p,"HL"))
+    	*res=s.HL;
+    else if (StrEq(p,"IX"))
+    	*res=s.IX;
+    else if (StrEq(p,"IY"))
+    	*res=s.IY;
+    else if (StrEq(p,"SP"))
+    	*res=s.SP;
+    else if (StrEq(p,"PC"))
+    	*res=s.PC;
+    else if (StrEq(p,"A"))
+    	*res=HI(s.AF);
+    else if (StrEq(p,"F"))
+    	*res=LO(s.AF);
+    else if (StrEq(p,"B"))
+    	*res=HI(s.BC);
+    else if (StrEq(p,"C"))
+    	*res=LO(s.BC);
+    else if (StrEq(p,"D"))
+    	*res=HI(s.DE);
+    else if (StrEq(p,"E"))
+    	*res=LO(s.DE);
+    else if (StrEq(p,"H"))
+    	*res=HI(s.HL);
+    else if (StrEq(p,"L"))
+    	*res=LO(s.HL);
+    else if (StrEq(p,"AF_"))
+    	*res=s.AF_;
+    else if (StrEq(p,"BC_"))
+    	*res=s.BC_;
+    else if (StrEq(p,"DE_"))
+    	*res=s.DE_;
+    else if (StrEq(p,"HL_"))
+    	*res=s.HL_;
+    else if (StrEq(p,"A_"))
+    	*res=HI(s.AF_);
+    else if (StrEq(p,"F_"))
+    	*res=LO(s.AF_);
+    else if (StrEq(p,"B_"))
+    	*res=HI(s.BC_);
+    else if (StrEq(p,"C_"))
+    	*res=LO(s.BC_);
+    else if (StrEq(p,"D_"))
+    	*res=HI(s.DE_);
+    else if (StrEq(p,"E_"))
+    	*res=LO(s.DE_);
+    else if (StrEq(p,"H_"))
+    	*res=HI(s.HL_);
+    else if (StrEq(p,"L_"))
+	*res=LO(s.HL_);
+    else if (StrEq(p,"IM"))
+	*res=s.IM;
+    else if (StrEq(p,"R"))
+	*res=s.R;
+    else if (StrEq(p,"IFF1"))
+	*res=s.IFF1;
+    else if (StrEq(p,"IFF2"))
+	*res=s.IFF2;
+    else if (p[0]=='@')
+    {
+	Z80Word n;
+
+	n=Address(p+1);
+	*res=mem[n];
+    }
+    else if (p[0]=='#')
+    {
+	Z80Word n;
+
+	n=Address(p+1);
+	*res=MK(mem[n+1],mem[n]);
+    }
+    else        /* Check for labels */
+    {
+        int f;
+
+        ok=FALSE;
+
+        for(f=0;label && label[f].label;f++)
+        {
+            if (StrEq(p,label[f].label))
+            {
+                *res=label[f].address;
+                ok=TRUE;
+                break;
+            }
+        }
+    }
+
+    return ok;
+}
+
+
+static Z80Word Address(const char *p)
+{
+    long e=0;
+
+    if (!ExprEval(p,&e,Expand,z80))
+	Log("%s\n",ExprError());
+
+    return (Z80Word)e;
+}
+
+
+static void *Malloc(size_t len)
+{
+    void *n;
+
+    n=malloc(len);
+
+    if (!n)
+    {
+    	fprintf(stderr,"malloc failed\n");
+	exit(EXIT_FAILURE);
+    }
+
+    return n;
+}
+
+static void *Realloc(void *p, size_t len)
+{
+    void *n;
+
+    n=realloc(p,len);
+
+    if (!n)
+    {
+    	fprintf(stderr,"realloc failed\n");
+	exit(EXIT_FAILURE);
+    }
+
+    return n;
+}
+
+static char *StrCopy(const char *p)
+{
+    return strcpy(Malloc(strlen(p)+1),p);
+}
+
+static const int ToHex(char c)
+{
+    c=toupper(c);
+
+    if (c>='0' && c<='9')
+    	return c-'0';
+
+    if (c>='A' && c<='F')
+    	return c-'A'+10;
+
+    return 0;
+}
+
+static void FlagString(DString s, Z80Byte flag, Z80Byte last)
+{
+    static char buff[32];
+    static char *c[]={"S","Z","5","H","3","P","N","C"};
+    int f;
+
+    sprintf(buff,"%-10.10s: ","Flags");
+
+    DSAdd(s,buff);
+
+    for(f=0;f<8;f++)
+    {
+	int b=1<<(7-f);
+
+	if ((last&b)!=(flag&b))
+	{
+	    DSAdd(s,"<span foreground=\"white\" background=\"black\">");
+	}
+
+	if (flag&b)
+	{
+	    DSAdd(s,c[f]);
+	}
+	else
+	{
+	    DSAdd(s,"-");
+	}
+
+	if ((last&b)!=(flag&b))
+	{
+	    DSAdd(s,"</span>");
+	}
+    }
+}
+
+
+static void DisplayState(DString s, const char *label,
+			 int width, Z80Val val, Z80Val last)
+{
+    static char buff[128];
+
+    sprintf(buff,"%s: %s%*.*lX</span>",
+		    label,
+		    (last==val) ?
+		    	"<span>" :
+			"<span foreground=\"white\" background=\"black\">",
+		    width,width,
+		    val);
+
+    DSAdd(s,buff);
+}
+
+
+/* ---------------------------------------- MEMORY
+*/
+static Z80Byte ReadPort(Z80 *z80, Z80Word addr)
+{
+    Z80Byte b=0xff;
+    Z80Word ptr;
+    Z80State s;
+    char expr[1024];
+    char *p;
+
+    Z80GetState(z80,&s);
+
+    switch(addr&0xff)
+    {
+    	case 0x80:
+	    ptr=MK(mem[1],mem[0]);
+
+	    p=expr;
+
+	    while(mem[ptr])
+	    	*p++=mem[ptr++];
+
+	    *p=0;
+
+	    b=(Z80Byte)Address(expr);
+
+	    /* Log("%s -> %u\n",expr,b); */
+
+	    break;
+
+    	case 0x81:
+	    ptr=s.DE;
+
+	    p=expr;
+
+	    while(mem[ptr])
+	    	*p++=mem[ptr++];
+
+	    *p=0;
+
+	    b=(Z80Byte)Address(expr);
+
+	    break;
+
+	default:
+	    Log("Read from port 0x%4.4x\n",(int)addr);
+	    break;
+    }
+
+    return b;
+}
+
+
+static void WritePort(Z80 *z80, Z80Word addr, Z80Byte val)
+{
+    Z80State s;
+    DString ds;
+
+    ds=DSInit();
+    Z80GetState(z80,&s);
+
+    switch(addr&0xff)
+    {
+    	case 0x80:
+	    DSAddChar(ds,val);
+	    break;
+
+	case 0x81:
+	    DSAdd(ds,"Stop requested via OUT(0x81)\n");
+	    stop=TRUE;
+	    break;
+
+    	case 0x82:
+	    while(mem[s.DE]!='$')
+	    {
+		if (isspace(mem[s.DE]) || isprint(mem[s.DE]))
+		{
+		    DSAddChar(ds,mem[s.DE]);
+		}
+
+		s.DE++;
+	    }
+	    break;
+
+    	case 0x83:
+	    while(mem[s.DE])
+	    {
+		DSAddChar(ds,mem[s.DE]);
+		s.DE++;
+	    }
+	    break;
+
+	default:
+	    Log("Wrote 0x%2.2x to port 0x%4.4x\n",(int)val,(int)addr);
+	    return;
+    }
+
+    Log(ds->text);
+    DSFree(ds);
+}
+
+
+static int Halt(Z80 *z80, Z80Val v)
+{
+
+    Log("**** Processor halted\n");
+    DialogOK("Processor halted\n");
+    stop=TRUE;
+    return FALSE;
+}
+
+
+/* ---------------------------------------- EXPORTED FUNCTIONS
+*/
+void GEMMA_UpdateDisplay(GEMMA_View view)
+{
+    if (view&UPDATE_ASSEM_VIEW)
+    {
+	Z80State reg;
+	DString ds;
+	int f;
+
+	ds=DSInit();
+	Z80GetState(z80,&reg);
+	DSAdd(ds,"<tt>");
+
+	for(f=0;f<20;f++)
+	{
+	    if (f==0)
+	    {
+	    	DSAdd(ds,"<span foreground=\"white\" background=\"black\">");
+	    }
+
+	    DSAdd(ds,Z80Disassemble(z80,&reg.PC));
+
+	    if (f==0)
+	    {
+	    	DSAdd(ds,"</span>");
+	    }
+
+	    DSAddChar(ds,'\n');
+	}
+
+	DSAdd(ds,"</tt>");
+	gtk_label_set_markup(GTK_LABEL(assemview),ds->text);
+
+	DSFree(ds);
+    }
+
+    if (view&UPDATE_REG_VIEW)
+    {
+	static int reg_once=FALSE;
+	static Z80State last_reg;
+	Z80State reg;
+	DString ds;
+
+	ds=DSInit();
+	Z80GetState(z80,&reg);
+
+	if (!reg_once)
+	{
+	    last_reg=reg;
+	}
+
+	DSAdd(ds,"<tt>");
+
+	DisplayState(ds,"A",2,HI(reg.AF),HI(last_reg.AF));
+	DSAdd(ds,"    ");
+	FlagString(ds,LO(reg.AF),LO(last_reg.AF));
+	DSAdd(ds,"\n");
+
+	DisplayState(ds,"BC",4,reg.BC,last_reg.BC);
+	DSAdd(ds,"    ");
+	DisplayState(ds,"DE",4,reg.DE,last_reg.DE);
+	DSAdd(ds,"    ");
+	DisplayState(ds,"HL",4,reg.HL,last_reg.HL);
+	DSAdd(ds,"\n");
+
+	DisplayState(ds,"SP",4,reg.SP,last_reg.SP);
+	DSAdd(ds,"    ");
+	DisplayState(ds,"IX",4,reg.IX,last_reg.IX);
+	DSAdd(ds,"    ");
+	DisplayState(ds,"IY",4,reg.IY,last_reg.IY);
+	DSAdd(ds,"\n");
+
+	DisplayState(ds,"AF'",4,reg.AF_,last_reg.AF_);
+	DSAdd(ds,"    ");
+	DisplayState(ds,"BC'",4,reg.BC_,last_reg.BC_);
+	DSAdd(ds,"    ");
+	DisplayState(ds,"DE'",4,reg.DE_,last_reg.DE_);
+	DSAdd(ds,"    ");
+	DisplayState(ds,"HL'",4,reg.HL_,last_reg.HL_);
+	DSAdd(ds,"\n");
+
+	DisplayState(ds,"PC",4,reg.PC,last_reg.PC);
+	DSAdd(ds,"\n");
+	DisplayState(ds,"R",4,reg.R,last_reg.R);
+	DSAdd(ds,"\n");
+	DisplayState(ds,"CYCLES",8,reg.cycle,last_reg.cycle);
+	DSAdd(ds,"\n");
+
+	DSAdd(ds,"</tt>");
+
+	gtk_label_set_markup(GTK_LABEL(regview),ds->text);
+
+	DSFree(ds);
+
+	last_reg=reg;
+    }
+}
+
+
+void GEMMA_LoadHEX(const char *path)
+{
+    FILE *fp;
+    char buff[1024];
+    int done=FALSE;
+
+    if (!(fp=fopen(path,"r")))
+    {
+    	Log("Failed to open %s\n",path);
+	return;
+    }
+
+    while(!done)
+    {
+    	if (!fgets(buff,sizeof buff,fp))
+	{
+	    Log("Missing EOF record\n");
+	    done=TRUE;
+	}
+
+	if (!done && buff[0]!=':')
+	{
+	    Log("Invalid Intel HEX file\n");
+	    done=TRUE;
+	}
+
+	if (!done && buff[8]=='1')
+	{
+	    Log("<EOF>\n");
+	    done=TRUE;
+	}
+
+	if (!done)
+	{
+	    Z80Word addr;
+	    int len;
+	    int f;
+
+	    len=ToHex(buff[1])<<4|ToHex(buff[2]);
+
+	    addr=ToHex(buff[3])<<12|ToHex(buff[4])<<8|
+		 ToHex(buff[5])<<4|ToHex(buff[6]);
+
+	    Log("Segment of 0x%2.2x bytes at address 0x%4.4x\n",len,addr);
+
+	    for(f=0;f<len;f++)
+	    {
+	    	Z80Byte b;
+
+		b=ToHex(buff[f*2+9])<<4|ToHex(buff[f*2+10]);
+		mem[addr++]=b;
+	    }
+	}
+    }
+
+    fclose(fp);
+
+    GEMMA_UpdateDisplay(UPDATE_ALL_VIEWS);
+}
+
+
+void GEMMA_LoadLabels(const char *path)
+{
+    FILE *fp;
+    int f;
+    char buff[512];
+
+    if (!(fp=fopen(path,"r")))
+    {
+    	Log("Failed to open %s\n",path);
+	return;
+    }
+
+    for(f=0;label && label[f].label;f++)
+    	free((void *)label[f].label);
+
+    free(label);
+    label=NULL;
+    f=0;
+
+    while(fgets(buff,sizeof buff,fp))
+    {
+    	char *name=NULL;
+	char *addr=NULL;
+
+	if (strlen(buff) && buff[strlen(buff)-1]=='\n')
+	    buff[strlen(buff)-1]=0;
+
+	name=strtok(buff," \t");
+
+	if (name)
+	    addr=strtok(NULL," \t");
+
+	if (name && addr)
+	{
+	    label=Realloc(label,sizeof(*label)*(f+2));
+
+	    label[f].label=StrCopy(name);
+	    label[f].address=Address(addr);
+
+	    f++;
+	}
+    }
+
+    if (label)
+    	label[f].label=NULL;
+
+    Z80SetLabels(label);
+
+    fclose(fp);
+}
+
+
+void GEMMA_Step(void)
+{
+    Z80SingleStep(z80);
+    GEMMA_UpdateDisplay(UPDATE_ALL_VIEWS);
+}
+
+
+void GEMMA_StepOver(void)
+{
+    Z80Word next;
+    Z80State reg;
+
+    stop=FALSE;
+
+    Z80GetState(z80,&reg);
+    next=reg.PC;
+    Z80Disassemble(z80,&next);
+
+    RUNNING(TRUE);
+
+    while(reg.PC!=next && !stop)
+    {
+    	GEMMA_Step();
+	Z80GetState(z80,&reg);
+	gtk_main_iteration_do(FALSE);
+    }
+
+    RUNNING(FALSE);
+}
+
+
+void GEMMA_Run(void)
+{
+    stop=FALSE;
+
+    RUNNING(TRUE);
+
+    while(!stop)
+    {
+    	GEMMA_Step();
+	gtk_main_iteration_do(FALSE);
+    }
+
+    RUNNING(FALSE);
+}
+
+
+void GEMMA_RunUntil(const char *expr)
+{
+    stop=FALSE;
+
+    RUNNING(TRUE);
+
+    while(!stop)
+    {
+	long e;
+
+	if (!ExprEval(expr,&e,Expand,z80))
+	{
+	    Log("%s\n",ExprError());
+	    stop=TRUE;
+	    continue;
+	}
+
+	if (e)
+	{
+	    Log("%s TRUE\n",expr);
+	    stop=TRUE;
+	    continue;
+	}
+
+    	GEMMA_Step();
+	gtk_main_iteration_do(FALSE);
+    }
+
+    RUNNING(FALSE);
+}
+
+
+void GEMMA_Stop(void)
+{
+    stop=TRUE;
+}
+
+
+void GEMMA_Init(GtkWidget *top)
+{
+    int f;
+
+    for(f=0;f<256;f++) memctl[f]=1;
+
+    z80=Z80Init(mem,memctl,WritePort,ReadPort);
+
+    if (!z80)
+    {
+    	fprintf(stderr,"Failed to initialise Z80\n");
+	exit(EXIT_FAILURE);
+    }
+
+    Z80LodgeCallback(z80,eZ80_Halt,Halt);
+
+    top_window=top;
+    regview=lookup_widget(top_window,"register_view");
+    memview=lookup_widget(top_window,"memory_view");
+    viewreg=lookup_widget(top_window,"memory_view_choice");
+    logview=lookup_widget(top_window,"log_view");
+    assemview=lookup_widget(top_window,"assem_view");
+}
+
+
+void GEMMA_Interrupt(int nmi)
+{
+    if (nmi)
+    {
+	Z80NMI(z80);
+    }
+    else
+    {
+    	Z80Interrupt(z80,0);
+    }
+}
+
+
+/* END OF FILE */
diff --git a/gemma.glade b/gemma.glade
index 3e944ac..a38cc57 100644
--- a/gemma.glade
+++ b/gemma.glade
@@ -4,145 +4,149 @@
 <glade-interface>
 
 <widget class="GtkWindow" id="top_window">
+  <property name="width_request">900</property>
+  <property name="height_request">600</property>
   <property name="visible">True</property>
   <property name="title" translatable="yes">GEMMA</property>
   <property name="type">GTK_WINDOW_TOPLEVEL</property>
   <property name="window_position">GTK_WIN_POS_NONE</property>
   <property name="modal">False</property>
-  <property name="default_width">770</property>
-  <property name="default_height">640</property>
-  <property name="resizable">True</property>
+  <property name="default_width">800</property>
+  <property name="default_height">600</property>
+  <property name="resizable">False</property>
   <property name="destroy_with_parent">True</property>
   <property name="decorated">True</property>
   <property name="skip_taskbar_hint">False</property>
   <property name="skip_pager_hint">False</property>
-  <property name="type_hint">GDK_WINDOW_TYPE_HINT_DIALOG</property>
+  <property name="type_hint">GDK_WINDOW_TYPE_HINT_NORMAL</property>
   <property name="gravity">GDK_GRAVITY_NORTH_WEST</property>
   <property name="focus_on_map">True</property>
   <property name="urgency_hint">False</property>
 
   <child>
-    <widget class="GtkVBox" id="vbox2">
+    <widget class="GtkVBox" id="vbox4">
       <property name="visible">True</property>
       <property name="homogeneous">False</property>
       <property name="spacing">0</property>
 
       <child>
-	<widget class="GtkVBox" id="vbox3">
-	  <property name="border_width">3</property>
+	<widget class="GtkHBox" id="hbox2">
 	  <property name="visible">True</property>
-	  <property name="homogeneous">False</property>
+	  <property name="homogeneous">True</property>
 	  <property name="spacing">0</property>
 
 	  <child>
-	    <widget class="GtkVPaned" id="vpaned1">
+	    <widget class="GtkLabel" id="assem_view">
 	      <property name="visible">True</property>
-	      <property name="can_focus">True</property>
-	      <property name="position">0</property>
+	      <property name="label" translatable="yes">&lt;b&gt;Assembler View&lt;/b&gt;</property>
+	      <property name="use_underline">False</property>
+	      <property name="use_markup">True</property>
+	      <property name="justify">GTK_JUSTIFY_LEFT</property>
+	      <property name="wrap">False</property>
+	      <property name="selectable">False</property>
+	      <property name="xalign">0</property>
+	      <property name="yalign">0</property>
+	      <property name="xpad">0</property>
+	      <property name="ypad">0</property>
+	      <property name="ellipsize">PANGO_ELLIPSIZE_NONE</property>
+	      <property name="width_chars">-1</property>
+	      <property name="single_line_mode">False</property>
+	      <property name="angle">0</property>
+	    </widget>
+	    <packing>
+	      <property name="padding">0</property>
+	      <property name="expand">True</property>
+	      <property name="fill">True</property>
+	    </packing>
+	  </child>
+
+	  <child>
+	    <widget class="GtkLabel" id="register_view">
+	      <property name="visible">True</property>
+	      <property name="label" translatable="yes">&lt;b&gt;Regsiter View&lt;/b&gt;</property>
+	      <property name="use_underline">False</property>
+	      <property name="use_markup">True</property>
+	      <property name="justify">GTK_JUSTIFY_LEFT</property>
+	      <property name="wrap">False</property>
+	      <property name="selectable">False</property>
+	      <property name="xalign">0</property>
+	      <property name="yalign">0</property>
+	      <property name="xpad">0</property>
+	      <property name="ypad">0</property>
+	      <property name="ellipsize">PANGO_ELLIPSIZE_NONE</property>
+	      <property name="width_chars">-1</property>
+	      <property name="single_line_mode">False</property>
+	      <property name="angle">0</property>
+	    </widget>
+	    <packing>
+	      <property name="padding">0</property>
+	      <property name="expand">True</property>
+	      <property name="fill">True</property>
+	    </packing>
+	  </child>
+	</widget>
+	<packing>
+	  <property name="padding">0</property>
+	  <property name="expand">True</property>
+	  <property name="fill">True</property>
+	</packing>
+      </child>
+
+      <child>
+	<widget class="GtkHBox" id="hbox1">
+	  <property name="height_request">1</property>
+	  <property name="visible">True</property>
+	  <property name="homogeneous">True</property>
+	  <property name="spacing">0</property>
+
+	  <child>
+	    <widget class="GtkVBox" id="vbox5">
+	      <property name="visible">True</property>
+	      <property name="homogeneous">False</property>
+	      <property name="spacing">0</property>
 
 	      <child>
-		<widget class="GtkHPaned" id="hpaned1">
+		<widget class="GtkComboBox" id="memory_view_choice">
 		  <property name="visible">True</property>
-		  <property name="can_focus">True</property>
-		  <property name="position">0</property>
-
-		  <child>
-		    <widget class="GtkScrolledWindow" id="scrolledwindow2">
-		      <property name="visible">True</property>
-		      <property name="can_focus">True</property>
-		      <property name="hscrollbar_policy">GTK_POLICY_ALWAYS</property>
-		      <property name="vscrollbar_policy">GTK_POLICY_ALWAYS</property>
-		      <property name="shadow_type">GTK_SHADOW_IN</property>
-		      <property name="window_placement">GTK_CORNER_TOP_LEFT</property>
-
-		      <child>
-			<widget class="GtkTreeView" id="assem_view">
-			  <property name="visible">True</property>
-			  <property name="can_focus">True</property>
-			  <property name="headers_visible">False</property>
-			  <property name="rules_hint">False</property>
-			  <property name="reorderable">False</property>
-			  <property name="enable_search">False</property>
-			  <property name="fixed_height_mode">True</property>
-			  <property name="hover_selection">False</property>
-			  <property name="hover_expand">False</property>
-			</widget>
-		      </child>
-		    </widget>
-		    <packing>
-		      <property name="shrink">True</property>
-		      <property name="resize">False</property>
-		    </packing>
-		  </child>
-
-		  <child>
-		    <widget class="GtkScrolledWindow" id="scrolledwindow3">
-		      <property name="visible">True</property>
-		      <property name="can_focus">True</property>
-		      <property name="hscrollbar_policy">GTK_POLICY_ALWAYS</property>
-		      <property name="vscrollbar_policy">GTK_POLICY_ALWAYS</property>
-		      <property name="shadow_type">GTK_SHADOW_IN</property>
-		      <property name="window_placement">GTK_CORNER_TOP_LEFT</property>
-
-		      <child>
-			<widget class="GtkTreeView" id="register_view">
-			  <property name="visible">True</property>
-			  <property name="can_focus">True</property>
-			  <property name="headers_visible">False</property>
-			  <property name="rules_hint">False</property>
-			  <property name="reorderable">False</property>
-			  <property name="enable_search">False</property>
-			  <property name="fixed_height_mode">True</property>
-			  <property name="hover_selection">False</property>
-			  <property name="hover_expand">False</property>
-			</widget>
-		      </child>
-		    </widget>
-		    <packing>
-		      <property name="shrink">True</property>
-		      <property name="resize">True</property>
-		    </packing>
-		  </child>
+		  <property name="items" translatable="yes">SP
+HL
+IX
+IY
+BC
+DE</property>
+		  <property name="add_tearoffs">False</property>
+		  <property name="focus_on_click">True</property>
+		  <signal name="changed" handler="OnMemoryViewChoice" last_modification_time="Tue, 29 Aug 2006 23:31:24 GMT"/>
 		</widget>
 		<packing>
-		  <property name="shrink">True</property>
-		  <property name="resize">False</property>
+		  <property name="padding">0</property>
+		  <property name="expand">False</property>
+		  <property name="fill">False</property>
 		</packing>
 	      </child>
 
 	      <child>
-		<widget class="GtkScrolledWindow" id="scrolledwindow1">
+		<widget class="GtkLabel" id="memory_view">
 		  <property name="visible">True</property>
-		  <property name="can_focus">True</property>
-		  <property name="hscrollbar_policy">GTK_POLICY_ALWAYS</property>
-		  <property name="vscrollbar_policy">GTK_POLICY_ALWAYS</property>
-		  <property name="shadow_type">GTK_SHADOW_IN</property>
-		  <property name="window_placement">GTK_CORNER_TOP_LEFT</property>
-
-		  <child>
-		    <widget class="GtkTextView" id="log_view">
-		      <property name="border_width">1</property>
-		      <property name="visible">True</property>
-		      <property name="can_focus">True</property>
-		      <property name="editable">False</property>
-		      <property name="overwrite">False</property>
-		      <property name="accepts_tab">True</property>
-		      <property name="justification">GTK_JUSTIFY_LEFT</property>
-		      <property name="wrap_mode">GTK_WRAP_CHAR</property>
-		      <property name="cursor_visible">False</property>
-		      <property name="pixels_above_lines">0</property>
-		      <property name="pixels_below_lines">0</property>
-		      <property name="pixels_inside_wrap">0</property>
-		      <property name="left_margin">0</property>
-		      <property name="right_margin">0</property>
-		      <property name="indent">0</property>
-		      <property name="text" translatable="yes"></property>
-		    </widget>
-		  </child>
+		  <property name="label" translatable="yes">&lt;b&gt;Memory View&lt;/b&gt;</property>
+		  <property name="use_underline">False</property>
+		  <property name="use_markup">True</property>
+		  <property name="justify">GTK_JUSTIFY_LEFT</property>
+		  <property name="wrap">False</property>
+		  <property name="selectable">False</property>
+		  <property name="xalign">0</property>
+		  <property name="yalign">0</property>
+		  <property name="xpad">0</property>
+		  <property name="ypad">0</property>
+		  <property name="ellipsize">PANGO_ELLIPSIZE_NONE</property>
+		  <property name="width_chars">-1</property>
+		  <property name="single_line_mode">False</property>
+		  <property name="angle">0</property>
 		</widget>
 		<packing>
-		  <property name="shrink">True</property>
-		  <property name="resize">True</property>
+		  <property name="padding">0</property>
+		  <property name="expand">False</property>
+		  <property name="fill">True</property>
 		</packing>
 	      </child>
 	    </widget>
@@ -154,93 +158,163 @@
 	  </child>
 
 	  <child>
-	    <widget class="GtkHButtonBox" id="hbuttonbox1">
+	    <widget class="GtkScrolledWindow" id="scrolledwindow1">
 	      <property name="visible">True</property>
-	      <property name="layout_style">GTK_BUTTONBOX_START</property>
-	      <property name="spacing">10</property>
+	      <property name="can_focus">True</property>
+	      <property name="hscrollbar_policy">GTK_POLICY_ALWAYS</property>
+	      <property name="vscrollbar_policy">GTK_POLICY_ALWAYS</property>
+	      <property name="shadow_type">GTK_SHADOW_IN</property>
+	      <property name="window_placement">GTK_CORNER_TOP_LEFT</property>
 
 	      <child>
-		<widget class="GtkButton" id="run_button">
+		<widget class="GtkTextView" id="log_view">
 		  <property name="visible">True</property>
-		  <property name="can_default">True</property>
 		  <property name="can_focus">True</property>
-		  <property name="label" translatable="yes">Run</property>
-		  <property name="use_underline">True</property>
-		  <property name="relief">GTK_RELIEF_NORMAL</property>
-		  <property name="focus_on_click">True</property>
+		  <property name="editable">False</property>
+		  <property name="overwrite">False</property>
+		  <property name="accepts_tab">True</property>
+		  <property name="justification">GTK_JUSTIFY_LEFT</property>
+		  <property name="wrap_mode">GTK_WRAP_CHAR</property>
+		  <property name="cursor_visible">False</property>
+		  <property name="pixels_above_lines">0</property>
+		  <property name="pixels_below_lines">0</property>
+		  <property name="pixels_inside_wrap">0</property>
+		  <property name="left_margin">0</property>
+		  <property name="right_margin">0</property>
+		  <property name="indent">0</property>
+		  <property name="text" translatable="yes"></property>
 		</widget>
 	      </child>
+	    </widget>
+	    <packing>
+	      <property name="padding">0</property>
+	      <property name="expand">True</property>
+	      <property name="fill">True</property>
+	    </packing>
+	  </child>
+	</widget>
+	<packing>
+	  <property name="padding">0</property>
+	  <property name="expand">True</property>
+	  <property name="fill">True</property>
+	</packing>
+      </child>
 
-	      <child>
-		<widget class="GtkButton" id="step_button">
-		  <property name="visible">True</property>
-		  <property name="can_default">True</property>
-		  <property name="can_focus">True</property>
-		  <property name="label" translatable="yes">Step</property>
-		  <property name="use_underline">True</property>
-		  <property name="relief">GTK_RELIEF_NORMAL</property>
-		  <property name="focus_on_click">True</property>
-		</widget>
-	      </child>
+      <child>
+	<widget class="GtkHButtonBox" id="hbuttonbox1">
+	  <property name="border_width">4</property>
+	  <property name="visible">True</property>
+	  <property name="layout_style">GTK_BUTTONBOX_SPREAD</property>
+	  <property name="spacing">0</property>
 
-	      <child>
-		<widget class="GtkButton" id="step_over_button">
-		  <property name="visible">True</property>
-		  <property name="can_default">True</property>
-		  <property name="can_focus">True</property>
-		  <property name="label" translatable="yes">Step Over</property>
-		  <property name="use_underline">True</property>
-		  <property name="relief">GTK_RELIEF_NORMAL</property>
-		  <property name="focus_on_click">True</property>
-		</widget>
-	      </child>
+	  <child>
+	    <widget class="GtkButton" id="run_button">
+	      <property name="visible">True</property>
+	      <property name="can_default">True</property>
+	      <property name="can_focus">True</property>
+	      <property name="label" translatable="yes">Run</property>
+	      <property name="use_underline">True</property>
+	      <property name="relief">GTK_RELIEF_NORMAL</property>
+	      <property name="focus_on_click">True</property>
+	      <signal name="clicked" handler="OnRun" last_modification_time="Mon, 28 Aug 2006 20:30:42 GMT"/>
+	    </widget>
+	  </child>
 
-	      <child>
-		<widget class="GtkButton" id="stop_button">
-		  <property name="visible">True</property>
-		  <property name="can_default">True</property>
-		  <property name="can_focus">True</property>
-		  <property name="label" translatable="yes">Stop</property>
-		  <property name="use_underline">True</property>
-		  <property name="relief">GTK_RELIEF_NORMAL</property>
-		  <property name="focus_on_click">True</property>
-		</widget>
-	      </child>
+	  <child>
+	    <widget class="GtkButton" id="step_button">
+	      <property name="visible">True</property>
+	      <property name="can_default">True</property>
+	      <property name="can_focus">True</property>
+	      <property name="label" translatable="yes">Step</property>
+	      <property name="use_underline">True</property>
+	      <property name="relief">GTK_RELIEF_NORMAL</property>
+	      <property name="focus_on_click">True</property>
+	      <signal name="clicked" handler="OnStep" last_modification_time="Mon, 28 Aug 2006 20:30:34 GMT"/>
+	    </widget>
+	  </child>
 
-	      <child>
-		<widget class="GtkButton" id="load_button">
-		  <property name="visible">True</property>
-		  <property name="can_default">True</property>
-		  <property name="can_focus">True</property>
-		  <property name="label" translatable="yes">Load HEX</property>
-		  <property name="use_underline">True</property>
-		  <property name="relief">GTK_RELIEF_NORMAL</property>
-		  <property name="focus_on_click">True</property>
-		</widget>
-	      </child>
+	  <child>
+	    <widget class="GtkButton" id="step_over_button">
+	      <property name="visible">True</property>
+	      <property name="can_default">True</property>
+	      <property name="can_focus">True</property>
+	      <property name="label" translatable="yes">Step Over</property>
+	      <property name="use_underline">True</property>
+	      <property name="relief">GTK_RELIEF_NORMAL</property>
+	      <property name="focus_on_click">True</property>
+	      <signal name="clicked" handler="OnStepOver" last_modification_time="Mon, 28 Aug 2006 20:30:21 GMT"/>
+	    </widget>
+	  </child>
 
-	      <child>
-		<widget class="GtkButton" id="quit_button">
-		  <property name="visible">True</property>
-		  <property name="can_default">True</property>
-		  <property name="can_focus">True</property>
-		  <property name="label" translatable="yes">Quit</property>
-		  <property name="use_underline">True</property>
-		  <property name="relief">GTK_RELIEF_NORMAL</property>
-		  <property name="focus_on_click">True</property>
-		</widget>
-	      </child>
+	  <child>
+	    <widget class="GtkButton" id="stop_button">
+	      <property name="visible">True</property>
+	      <property name="sensitive">False</property>
+	      <property name="can_default">True</property>
+	      <property name="can_focus">True</property>
+	      <property name="label" translatable="yes">Stop</property>
+	      <property name="use_underline">True</property>
+	      <property name="relief">GTK_RELIEF_NORMAL</property>
+	      <property name="focus_on_click">True</property>
+	      <signal name="clicked" handler="OnStop" last_modification_time="Mon, 28 Aug 2006 20:30:16 GMT"/>
+	    </widget>
+	  </child>
+
+	  <child>
+	    <widget class="GtkButton" id="load_hex_button">
+	      <property name="visible">True</property>
+	      <property name="can_default">True</property>
+	      <property name="can_focus">True</property>
+	      <property name="label" translatable="yes">Load HEX</property>
+	      <property name="use_underline">True</property>
+	      <property name="relief">GTK_RELIEF_NORMAL</property>
+	      <property name="focus_on_click">True</property>
+	      <signal name="activate" handler="OnLoadHEX" last_modification_time="Mon, 28 Aug 2006 20:23:36 GMT"/>
+	    </widget>
+	  </child>
+
+	  <child>
+	    <widget class="GtkButton" id="load_labels_button">
+	      <property name="visible">True</property>
+	      <property name="can_default">True</property>
+	      <property name="can_focus">True</property>
+	      <property name="label" translatable="yes">Load Labels</property>
+	      <property name="use_underline">True</property>
+	      <property name="relief">GTK_RELIEF_NORMAL</property>
+	      <property name="focus_on_click">True</property>
+	      <signal name="clicked" handler="OnLoadLabels" last_modification_time="Mon, 28 Aug 2006 20:30:05 GMT"/>
+	    </widget>
+	  </child>
+
+	  <child>
+	    <widget class="GtkButton" id="run_until_button">
+	      <property name="visible">True</property>
+	      <property name="can_default">True</property>
+	      <property name="can_focus">True</property>
+	      <property name="label" translatable="yes">Run Until</property>
+	      <property name="use_underline">True</property>
+	      <property name="relief">GTK_RELIEF_NORMAL</property>
+	      <property name="focus_on_click">True</property>
+	      <signal name="clicked" handler="OnRunUntil" last_modification_time="Mon, 28 Aug 2006 20:30:00 GMT"/>
+	    </widget>
+	  </child>
+
+	  <child>
+	    <widget class="GtkButton" id="quit_button">
+	      <property name="visible">True</property>
+	      <property name="can_default">True</property>
+	      <property name="can_focus">True</property>
+	      <property name="label" translatable="yes">Quit</property>
+	      <property name="use_underline">True</property>
+	      <property name="relief">GTK_RELIEF_NORMAL</property>
+	      <property name="focus_on_click">True</property>
+	      <signal name="clicked" handler="OnQuit" last_modification_time="Mon, 28 Aug 2006 20:29:15 GMT"/>
 	    </widget>
-	    <packing>
-	      <property name="padding">7</property>
-	      <property name="expand">False</property>
-	      <property name="fill">True</property>
-	    </packing>
 	  </child>
 	</widget>
 	<packing>
 	  <property name="padding">0</property>
-	  <property name="expand">True</property>
+	  <property name="expand">False</property>
 	  <property name="fill">True</property>
 	</packing>
       </child>
diff --git a/gemma.h b/gemma.h
new file mode 100644
index 0000000..c7ccc1d
--- /dev/null
+++ b/gemma.h
@@ -0,0 +1,56 @@
+/*
+
+    GEMMA - Z80 testbed
+
+    Copyright (C) 2006  Ian Cowburn (ianc@noddybox.demon.co.uk)
+
+    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 GEMMA_H
+#define GEMMA_H "$Id$"
+
+#include <gtk/gtk.h>
+#include "z80.h"
+
+typedef enum
+{
+    UPDATE_ASSEM_VIEW=0x01,
+    UPDATE_REG_VIEW=0x02,
+    UPDATE_MEM_VIEW=0x04,
+    UPDATE_ALL_VIEWS=UPDATE_ASSEM_VIEW|UPDATE_REG_VIEW|UPDATE_MEM_VIEW
+} GEMMA_View;
+
+void		GEMMA_Init(GtkWidget *top);
+void		GEMMA_LoadHEX(const char *path);
+void		GEMMA_LoadLabels(const char *path);
+void		GEMMA_UpdateDisplay(GEMMA_View view);
+void		GEMMA_Step(void);
+void		GEMMA_StepOver(void);
+void		GEMMA_Run(void);
+void		GEMMA_RunUntil(const char *expr);
+void		GEMMA_Stop(void);
+void		GEMMA_Interrupt(int nmi);
+
+#endif
+
+/* END OF FILE */
+
+
diff --git a/gtkutil.c b/gtkutil.c
index da08e1b..b5ec30c 100644
--- a/gtkutil.c
+++ b/gtkutil.c
@@ -49,7 +49,7 @@ static int		selected=FALSE;
 static char		saved_path[PATH_MAX+1];
 
 
-/* ---------------------------------------- CALLBACKS
+/* ---------------------------------------- PRIVATE FUNCTIONS
 */
 static void Callback(GtkWidget *w, gpointer data)
 {
@@ -85,7 +85,7 @@ static void FselCallback(GtkWidget *w, gpointer data)
 }
 
 
-/* ---------------------------------------- DialogParent()
+/* ---------------------------------------- EXPORTED FUNCTIONS
 */
 void DialogParent(GtkWidget *w)
 {
@@ -93,8 +93,6 @@ void DialogParent(GtkWidget *w)
 }
 
 
-/* ---------------------------------------- DialogOK()
-*/
 void DialogOK(const char *format, ...)
 {
     va_list va;
@@ -133,8 +131,6 @@ void DialogOK(const char *format, ...)
 }
 
 
-/* ---------------------------------------- DialogYesNo()
-*/
 int DialogYesNo(const char *format, ...)
 {
     va_list va;
@@ -194,8 +190,6 @@ int DialogYesNo(const char *format, ...)
 }
 
 
-/* ---------------------------------------- DialogFSelect()
-*/
 int DialogFSelect(const char *title, char path[])
 {
     dialog=gtk_file_selection_new(title);
@@ -236,4 +230,15 @@ int DialogFSelect(const char *title, char path[])
 }
 
 
+void AppendText(GtkWidget *w, const char *text)
+{
+    GtkTextBuffer *buff;
+    GtkTextIter end;
+
+    buff=gtk_text_view_get_buffer(GTK_TEXT_VIEW(w));
+    gtk_text_buffer_get_end_iter(buff,&end);
+    gtk_text_buffer_insert(buff,&end,text,-1);
+}
+
+
 /* END OF FILE */
diff --git a/gtkutil.h b/gtkutil.h
index 0385a5e..46717d2 100644
--- a/gtkutil.h
+++ b/gtkutil.h
@@ -55,6 +55,10 @@ int	DialogYesNo(const char *format, ...);
 */
 int	DialogFSelect(const char *title, char path[]);
 
+/* Append text to a text view
+*/
+void	AppendText(GtkWidget *w, const char *text);
+
 
 #endif
 
diff --git a/main.c b/main.c
index f4f66a4..f39e133 100644
--- a/main.c
+++ b/main.c
@@ -33,17 +33,31 @@ static const char ident[]="$Id$";
 #include "interface.h"
 #include "support.h"
 
+#include "gtkutil.h"
+#include "gemma.h"
+
 int main (int argc, char *argv[])
 {
-  GtkWidget *top_window;
+    GtkWidget *top_window;
+
+    gtk_set_locale ();
+    gtk_init (&argc, &argv);
+
+    top_window = create_top_window ();
+    gtk_widget_show (top_window);
 
-  gtk_set_locale ();
-  gtk_init (&argc, &argv);
+    DialogParent(top_window);
+    GEMMA_Init(top_window);
+    GEMMA_UpdateDisplay(UPDATE_ALL_VIEWS);
 
-  top_window = create_top_window ();
-  gtk_widget_show (top_window);
+    AppendText(lookup_widget(top_window,"log_view"),
+		"GEMMA, Copyright (C) 2006 Ian Cowburn\n"
+		"GEMMA comes with ABSOLUTELY NO WARRANTY\n"
+		"This is free software, and you are welcome\n"
+		"to redistribute it under certain conditions;\n"
+		"See the GNU General Public License for details.\n");
 
-  gtk_main ();
-  return 0;
+    gtk_main ();
+    return 0;
 }
 
diff --git a/z80.c b/z80.c
index cd2371a..a974c40 100644
--- a/z80.c
+++ b/z80.c
@@ -179,6 +179,12 @@ void Z80Reset(Z80 *cpu)
 }
 
 
+void Z80SetPC(Z80 *cpu,Z80Word PC)
+{
+    cpu->PC=PC;
+}
+
+
 void Z80ResetCycles(Z80 *cpu, Z80Val cycles)
 {
     cpu->cycle=cycles;
diff --git a/z80.h b/z80.h
index 3b3220e..5ac28b7 100644
--- a/z80.h
+++ b/z80.h
@@ -174,6 +174,11 @@ Z80	*Z80Init(Z80Memory memory,
 void	Z80Reset(Z80 *cpu);
 
 
+/* Sets the PC
+*/
+void	Z80SetPC(Z80 *cpu, Z80Word PC);
+
+
 /* Sets the cycle count to the specified count
 */
 void	Z80ResetCycles(Z80 *cpu, Z80Val cycles);