default preferences values for disassembly and debugger

supercharger tries to load BIOS before anything else meaning a quicker
failure if one is necessary

failed cartridge attachment will result in log entry rather than a
terminal error

loading cartridge without a coprocessor (ARM) when the Last Execution
window was open would cause a crash

added video link in readme

README.md

@@ -220,6 +220,8 @@ Below the menu-bar are the debugging windows. In this screenshot we can see:
 
 Note that much of the information presented in the windows is editable in-place. For example, the contents of the CPU's PC register can be edited via the window. As in all areas of this project, the user is encouraged to experiment.
 
+A video of the debugger in action can be found [here](https://www.youtube.com/watch?v=3vLyRw8iVCA).
+
 #### Debugger Terminal
 
 As an alternative to GUI interaction the debugger can also be controlled through a terminal. This is available through the `terminal` window. The rest of this section describes the operation of the terminal in detail.

debugger/debugger.go

@@ -403,9 +403,9 @@ func (dbg *Debugger) attachCartridge(cartload cartridgeloader.Loader) error {
 	// reset of vcs is implied with attach cartridge
 	err = setup.AttachCartridge(dbg.VCS, cartload)
 	if err != nil && !curated.Has(err, cartridge.Ejected) {
-		dbg.printLine(terminal.StyleError, "%v", err)
+		logger.Log("attach", err.Error())
 
-		// an error has occured so attach the ejected cartridge
+		// an error has occurred so attach the ejected cartridge
 		err = setup.AttachCartridge(dbg.VCS, cartridgeloader.Loader{})
 		if err != nil {
 			return err

disassembly/preferences.go

@@ -42,10 +42,12 @@ func (p *Preferences) String() string {
 
 // newPreferences is the preferred method of initialisation for the Preferences type.
 func newPreferences(dsm *Disassembly) (*Preferences, error) {
-	p := &Preferences{
-		dsm:          dsm,
-		mirrorOrigin: memorymap.OriginCart,
-	}
+	p := &Preferences{dsm: dsm}
+
+	// set defaults
+	p.FxxxMirror.Set(true)
+	p.Symbols.Set(true)
+	p.mirrorOrigin = memorymap.OriginCartFxxxMirror
 
 	// save server using the prefs package
 	pth, err := paths.ResourcePath("", prefs.DefaultPrefsFile)

gui/sdlimgui/preferences.go

@@ -44,6 +44,9 @@ type preferences struct {
 func newDebugPreferences(img *SdlImgui) (*preferences, error) {
 	p := &preferences{img: img}
 
+	// defaults
+	p.openOnError.Set(true)
+
 	// setup preferences
 	pth, err := paths.ResourcePath("", prefs.DefaultPrefsFile)
 	if err != nil {

gui/sdlimgui/win_coproc_lastexecution.go

@@ -55,6 +55,10 @@ func (win *winCoProcLastExecution) draw() {
 		return
 	}
 
+	if !win.img.lz.CoProc.HasCoProcBus || win.img.lz.Dbg.Disasm.Coprocessor == nil {
+		return
+	}
+
 	imgui.SetNextWindowPosV(imgui.Vec2{465, 285}, imgui.ConditionFirstUseEver, imgui.Vec2{0, 0})
 	imgui.SetNextWindowSizeV(imgui.Vec2{353, 466}, imgui.ConditionFirstUseEver)
 

hardware/memory/cartridge/supercharger/supercharger.go

@@ -68,6 +68,12 @@ func NewSupercharger(cartload cartridgeloader.Loader) (mapper.CartMapper, error)
 
 	var err error
 
+	// load bios and activate
+	cart.bios, err = loadBIOS(path.Dir(cartload.Filename))
+	if err != nil {
+		return nil, curated.Errorf("supercharger: %v", err)
+	}
+
 	// set up tape
 	if cartload.IsSoundData {
 		cart.state.tape, err = newSoundLoad(cart, cartload)
@@ -78,12 +84,6 @@ func NewSupercharger(cartload cartridgeloader.Loader) (mapper.CartMapper, error)
 		return nil, curated.Errorf("supercharger: %v", err)
 	}
 
-	// load bios and activate
-	cart.bios, err = loadBIOS(path.Dir(cartload.Filename))
-	if err != nil {
-		return nil, curated.Errorf("supercharger: %v", err)
-	}
-
 	// prepare onLoaded function
 	if cartload.OnLoaded == nil {
 		cart.onLoaded = func(cart mapper.CartMapper) error { return nil }