diff --git a/MA2ME/AppDelegate.m b/MA2ME/AppDelegate.m
index 4f0c4db..378f6d3 100644
--- a/MA2ME/AppDelegate.m
+++ b/MA2ME/AppDelegate.m
@@ -91,6 +91,9 @@ static NSString *kMyContext = @"kMyContext";
     [self addObserver: self forKeyPath: @"mameNoThrottle" options:0  context: (__bridge void * _Nullable)(kMyContext)];
     
     [_slotController addObserver: self forKeyPath: @"args" options: 0 context:  (__bridge void * _Nullable)(kMyContext)];
+    
+    [_mediaController bind: @"media" toObject: _slotController withKeyPath: @"media" options: 0];
+    
     [self buildCommandLine];
 }
 
diff --git a/MA2ME/Base.lproj/MainMenu.xib b/MA2ME/Base.lproj/MainMenu.xib
index 273494c..1afc79d 100644
--- a/MA2ME/Base.lproj/MainMenu.xib
+++ b/MA2ME/Base.lproj/MainMenu.xib
@@ -736,7 +736,7 @@
                     <button verticalHuggingPriority="750" fixedFrame="YES" translatesAutoresizingMaskIntoConstraints="NO" id="ug9-kz-ZSS">
                         <rect key="frame" x="621" y="53" width="85" height="32"/>
                         <autoresizingMask key="autoresizingMask" flexibleMinX="YES" flexibleMaxY="YES"/>
-                        <buttonCell key="cell" type="push" title="Launch" bezelStyle="rounded" alignment="center" borderStyle="border" imageScaling="proportionallyDown" inset="2" id="evD-kp-H2u">
+                        <buttonCell key="cell" type="push" title="Launch" bezelStyle="rounded" image="NSAppleMenuImage" imagePosition="leading" alignment="center" borderStyle="border" inset="2" id="evD-kp-H2u">
                             <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
                             <font key="font" metaFont="system"/>
                         </buttonCell>
@@ -778,4 +778,7 @@
         <viewController title="Slot View" nibName="SlotView" id="CYF-Xd-EdF" customClass="SlotViewController"/>
         <viewController title="Media View" nibName="MediaView" id="kiU-IX-LTW" customClass="MediaViewController"/>
     </objects>
+    <resources>
+        <image name="NSAppleMenuImage" width="128" height="128"/>
+    </resources>
 </document>
diff --git a/MA2ME/MA2ME/Base.lproj/MediaView.xib b/MA2ME/MA2ME/Base.lproj/MediaView.xib
index abe9772..59d3a0a 100644
--- a/MA2ME/MA2ME/Base.lproj/MediaView.xib
+++ b/MA2ME/MA2ME/Base.lproj/MediaView.xib
@@ -14,7 +14,7 @@
         </customObject>
         <customObject id="-1" userLabel="First Responder" customClass="FirstResponder"/>
         <customObject id="-3" userLabel="Application" customClass="NSObject"/>
-        <scrollView borderType="none" autohidesScrollers="YES" horizontalLineScroll="20" horizontalPageScroll="10" verticalLineScroll="20" verticalPageScroll="10" usesPredominantAxisScrolling="NO" id="nVT-kT-bWl">
+        <scrollView borderType="none" autohidesScrollers="YES" horizontalLineScroll="20" horizontalPageScroll="10" verticalLineScroll="20" verticalPageScroll="10" hasHorizontalScroller="NO" usesPredominantAxisScrolling="NO" id="nVT-kT-bWl">
             <rect key="frame" x="0.0" y="0.0" width="306" height="500"/>
             <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
             <clipView key="contentView" drawsBackground="NO" copiesOnScroll="NO" id="IBD-wb-pch">
@@ -81,17 +81,17 @@
                                         <rect key="frame" x="1" y="41" width="304" height="27"/>
                                         <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
                                         <subviews>
-                                            <pathControl verticalHuggingPriority="750" fixedFrame="YES" allowsExpansionToolTips="YES" translatesAutoresizingMaskIntoConstraints="NO" id="f7R-TO-fmF">
+                                            <pathControl focusRingType="none" verticalHuggingPriority="750" fixedFrame="YES" allowsExpansionToolTips="YES" translatesAutoresizingMaskIntoConstraints="NO" id="f7R-TO-fmF">
                                                 <rect key="frame" x="0.0" y="1" width="251" height="22"/>
                                                 <autoresizingMask key="autoresizingMask" widthSizable="YES" flexibleMinY="YES" flexibleMaxY="YES"/>
-                                                <pathCell key="cell" controlSize="small" selectable="YES" editable="YES" alignment="left" pathStyle="popUp" id="dcz-8y-tKb">
+                                                <pathCell key="cell" controlSize="small" selectable="YES" editable="YES" focusRingType="none" alignment="left" pathStyle="popUp" id="dcz-8y-tKb">
                                                     <font key="font" metaFont="smallSystem"/>
                                                 </pathCell>
                                             </pathControl>
                                             <button verticalHuggingPriority="750" fixedFrame="YES" translatesAutoresizingMaskIntoConstraints="NO" id="zNo-ij-mUl">
-                                                <rect key="frame" x="278" y="4" width="23" height="18"/>
+                                                <rect key="frame" x="256" y="5" width="23" height="18"/>
                                                 <autoresizingMask key="autoresizingMask" flexibleMinX="YES" flexibleMinY="YES" flexibleMaxY="YES"/>
-                                                <buttonCell key="cell" type="bevel" bezelStyle="rounded" image="NSStopProgressFreestandingTemplate" imagePosition="overlaps" alignment="center" controlSize="small" imageScaling="proportionallyDown" inset="2" id="IZA-Tu-olu">
+                                                <buttonCell key="cell" type="bevel" bezelStyle="rounded" image="NSNavEjectButton.normalSelected" imagePosition="overlaps" alignment="center" controlSize="small" imageScaling="proportionallyDown" inset="2" id="IZA-Tu-olu">
                                                     <behavior key="behavior" pushIn="YES" lightByBackground="YES" lightByGray="YES"/>
                                                     <font key="font" metaFont="smallSystem"/>
                                                 </buttonCell>
@@ -99,14 +99,9 @@
                                                     <action selector="buttonDelete:" target="-2" id="f30-YS-1UK"/>
                                                 </connections>
                                             </button>
-                                            <imageView horizontalHuggingPriority="251" verticalHuggingPriority="251" id="jeU-0Q-Eps">
-                                                <rect key="frame" x="256" y="6" width="14" height="14"/>
-                                                <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
-                                                <imageCell key="cell" enabled="NO" refusesFirstResponder="YES" alignment="left" image="NSStatusUnavailable" id="dtr-VF-lvn"/>
-                                            </imageView>
                                         </subviews>
                                         <connections>
-                                            <outlet property="imageView" destination="jeU-0Q-Eps" id="Cjz-C6-w1l"/>
+                                            <outlet property="deleteButton" destination="zNo-ij-mUl" id="9br-3c-ddI"/>
                                             <outlet property="pathControl" destination="f7R-TO-fmF" id="oH7-N3-JC7"/>
                                         </connections>
                                     </tableCellView>
@@ -122,7 +117,7 @@
                 <nil key="backgroundColor"/>
             </clipView>
             <scroller key="horizontalScroller" hidden="YES" wantsLayer="YES" verticalHuggingPriority="750" horizontal="YES" id="9Vz-lW-4GG">
-                <rect key="frame" x="0.0" y="485" width="306" height="15"/>
+                <rect key="frame" x="-100" y="-100" width="306" height="15"/>
                 <autoresizingMask key="autoresizingMask"/>
             </scroller>
             <scroller key="verticalScroller" hidden="YES" wantsLayer="YES" verticalHuggingPriority="750" horizontal="NO" id="f8l-nC-KhG">
@@ -133,7 +128,6 @@
         </scrollView>
     </objects>
     <resources>
-        <image name="NSStatusUnavailable" width="16" height="16"/>
-        <image name="NSStopProgressFreestandingTemplate" width="14" height="14"/>
+        <image name="NSNavEjectButton.normalSelected" width="128" height="128"/>
     </resources>
 </document>
diff --git a/MA2ME/MediaViewController.h b/MA2ME/MediaViewController.h
index efa00e2..f13f462 100644
--- a/MA2ME/MediaViewController.h
+++ b/MA2ME/MediaViewController.h
@@ -13,11 +13,11 @@ NS_ASSUME_NONNULL_BEGIN
 @interface MediaViewController : NSViewController <NSOutlineViewDelegate, NSOutlineViewDataSource>
 
 @property (weak) IBOutlet NSOutlineView *outlineView;
-
+@property (nonatomic) NSDictionary *media;
 - (IBAction)buttonDelete:(id)sender;
 
 
--(void)setMedia: (NSDictionary *)media;
+//-(void)setMedia: (NSDictionary *)media;
 
 @end
 
diff --git a/MA2ME/MediaViewController.m b/MA2ME/MediaViewController.m
index d2eba04..e71d54d 100644
--- a/MA2ME/MediaViewController.m
+++ b/MA2ME/MediaViewController.m
@@ -86,25 +86,26 @@
 
 
 -(BOOL)setItemCount: (unsigned)newCount {
-    unsigned count = (unsigned)[_children count];
-    if (count == newCount) return NO;
 
+    if (newCount == _validCount) {
+        return NO;
+    }
+
+    unsigned count = (unsigned)[_children count];
     NSMutableArray *tmp = [NSMutableArray arrayWithArray: _children];
 
     _validCount = newCount;
 
-    while (newCount > count) {
+    for (unsigned i = count; i < newCount; ++i) {
         [tmp addObject: [MediaItem new]];
-        ++count;
     }
     // delete excess items, if blank.  otherwise, mark invalid.
     unsigned ix = 0;
     for(MediaItem *item in tmp) {
-        [item setValid: ix < newCount];
+        [item setValid: ix++ < newCount];
     }
 
-    while (newCount > count) {
-        --newCount;
+    for (unsigned i = newCount; i < count; ++i) {
         MediaItem *item = [tmp lastObject];
         if ([item url]) break;
         
@@ -115,6 +116,25 @@
     return YES;
 }
 
+-(BOOL)pruneChildren {
+    NSUInteger count = [_children count];
+    BOOL delta = NO;
+    if (_validCount == count) return NO;
+
+    NSMutableArray *tmp = [NSMutableArray arrayWithArray: _children];
+    for (NSInteger i = _validCount; i < count; ++i) {
+        MediaItem *item = [tmp lastObject];
+        if ([item url]) break;
+    
+        [tmp removeLastObject];
+        delta = YES;
+    }
+    if (delta) {
+        [self setChildren: tmp];
+        return YES;
+    }
+    return NO;
+}
 @end
 
 
@@ -152,6 +172,10 @@
     [pc setURL: _url]; //??? will binding take care of it?
     [pc unbind: @"value"];
     [pc bind: @"value" toObject: self withKeyPath: @"url" options: nil];
+    
+    NSColor *tintColor = nil;
+    if (!_valid) tintColor = [NSColor redColor];
+    [[view deleteButton] setContentTintColor: tintColor];
 }
 
 -(CGFloat)height {
@@ -167,8 +191,8 @@
 
     MediaCategory *_data[5];
     NSArray *_root;
+    NSDictionary *_media;
 }
-@property (weak) IBOutlet NSPathControl *_hacky_hack;
 
 @end
 
@@ -196,28 +220,8 @@
     _data[3] = d;
     _data[4] = e;
 
-    _root = @[a,b,c,d,e];
-    
-    
-    [a setChildren: @[
-        [MediaItem new],
-        [MediaItem new],
-    ]];
+    _root = @[];
 
-    [b setChildren: @[
-        [MediaItem new],
-        [MediaItem new],
-    ]];
-
-    [c setChildren: @[
-        [MediaItem new],
-        [MediaItem new],
-    ]];
-
-    [d setChildren: @[
-        [MediaItem new],
-        [MediaItem new],
-    ]];
 }
 
 
@@ -228,6 +232,20 @@ enum {
     kIndexCDROM,
     kIndexCassette
 };
+
+-(void)rebuildRoot {
+    NSMutableArray *tmp = [NSMutableArray new];
+    for (unsigned j = 0 ; j < 5; ++j) {
+        MediaCategory *cat = _data[j];
+        if ([cat count]) [tmp addObject: cat];
+    }
+    _root = tmp;
+    //[_outlineView reloadItem: nil reloadChildren: YES];
+
+    [_outlineView reloadData];
+    [_outlineView expandItem: nil expandChildren: YES];
+}
+
 -(void)setMedia: (NSDictionary *)media {
     
     static NSString *Keys[] = {
@@ -237,11 +255,16 @@ enum {
         @"cdrm",
         @"cass"
     };
+
     NSNumber *o;
     MediaCategory *cat;
     unsigned i;
     BOOL delta = NO;
     
+    
+    if (_media == media) return;
+    _media = media;
+    
     for (unsigned j = 0; j < 5; ++j) {
     
         o = [media objectForKey: Keys[j]];
@@ -251,15 +274,7 @@ enum {
     }
 
     
-    if (delta) {
-        NSMutableArray *tmp = [NSMutableArray new];
-        for (unsigned j = 0 ; j < 5; ++j) {
-            MediaCategory *cat = _data[j];
-            if ([cat count]) [tmp addObject: cat];
-        }
-        _root = tmp;
-        [_outlineView reloadData];
-    }
+    if (delta) [self rebuildRoot];
 }
 
 - (void)viewDidLoad {
@@ -269,6 +284,7 @@ enum {
     //NSOutlineView *view = [self view];
     //[view expandItem: nil expandChildren: YES];
     // Do view setup here.
+    [_outlineView reloadData];
     [_outlineView expandItem: nil expandChildren: YES];
 }
 
@@ -364,5 +380,11 @@ enum {
     MediaItem *item = [_outlineView itemAtRow: row];
     [item setUrl: nil];
     //[[pv pathControl] setURL: nil];
+    
+    // if item is invalid, should attempt to remove...
+    if (![item valid]) {
+        MediaCategory *cat = [_outlineView parentForItem: item];
+        if ([cat pruneChildren]) [self rebuildRoot];
+    }
 }
 @end
diff --git a/SlotViewController.h b/SlotViewController.h
index 4d72f3a..21c89e6 100644
--- a/SlotViewController.h
+++ b/SlotViewController.h
@@ -37,6 +37,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property NSSize resolution;
 
 @property NSArray *args;
+@property NSDictionary *media;
 
 //-(void)setMachine: (NSDictionary *)machine;
 
diff --git a/SlotViewController.m b/SlotViewController.m
index d193c6e..0af4212 100644
--- a/SlotViewController.m
+++ b/SlotViewController.m
@@ -15,6 +15,10 @@ const unsigned kMemoryMask = 1 << 16;
     unsigned _slots_explicit;
     unsigned _slots_valid;
     unsigned _slots_default;
+    
+    NSDictionary *_slot_object[14];
+    NSDictionary *_slot_media[14];
+    NSDictionary *_machine_media;
 }
 
 @property (weak) IBOutlet NSPopUpButton *ram_menu;
@@ -89,7 +93,19 @@ const unsigned kMemoryMask = 1 << 16;
     _slots_explicit = 0;
     _slots_valid = 0;
 
+    _machine_media = nil;
+    
     [self setArgs: @[]];
+    [self setMedia: @{}];
+    
+
+#if 0
+    // retain for later?
+    for (unsigned i = 0; i < 14; ++i) {
+        _slot_media[i] = nil;
+        _slot_object[i] = nil;
+    }
+#endif
 }
 
 static NSFont *ItalicMenuFont(void) {
@@ -212,20 +228,26 @@ static void DeactivateMenus(NSArray *items, NSPopUpButton *button) {
             if ([value isEqualToString: [d objectForKey: @"value"]]) {
 
                 [button selectItemAtIndex: ix];
+                _slot_object[index] = d;
+                _slot_media[index] = [d objectForKey: @"media"];
                 return;
             }
             ++ix;
         }
     }
     _slots_explicit &= ~mask;
+    
     if (default_index) {
         NSDictionary *d = [items objectAtIndex: default_index];
         [button selectItemAtIndex: default_index];
         [self setValue: [d objectForKey: @"value"] forKey: slot];
+        _slot_object[index] = d;
+        _slot_media[index] = [d objectForKey: @"media"];
     } else {
-        
-        [self setValue: @"" forKey: slot];
         [button selectItemAtIndex: 0];
+        [self setValue: @"" forKey: slot];
+        _slot_object[index] = nil;
+        _slot_media[index] = nil;
     }
 }
 
@@ -267,11 +289,14 @@ static void DeactivateMenus(NSArray *items, NSPopUpButton *button) {
         res.height = [(NSNumber *)[r objectAtIndex: 1 /*@"height"*/] doubleValue];
     }
     [self setResolution: res];
+    
+    _machine_media = [d objectForKey: @"media"];
 
     // n.b. - does content binding propogate immediately?
     [self setMachine: d];
     [self syncSlots];
     [self rebuildArgs];
+    [self rebuildMedia];
 }
 
 
@@ -297,6 +322,16 @@ static void DeactivateMenus(NSArray *items, NSPopUpButton *button) {
     
     [self setValue: [o objectForKey: @"value"] forKey: key];
 
+    _slot_object[tag] = o;
+    NSDictionary *newMedia = [o objectForKey: @"media"];
+    NSDictionary *oldMedia = _slot_media[tag];
+
+    if (newMedia != oldMedia) {
+        _slot_media[tag] = newMedia;
+        [self rebuildMedia];
+    }
+    
+    
     [self rebuildArgs];
 }
 
@@ -359,8 +394,53 @@ static BOOL should_add_arg(unsigned slot, unsigned valid_slots, unsigned explici
     _(11, _gameio, @"-gameio")
     _(12, _printer, @"-printer")
     _(13, _modem, @"-modem")
-
+#undef _
     [self setArgs: args];
 }
 
+
+-(void)rebuildMedia {
+    
+
+#define _(var, o) var += [[o objectForKey: @ # var ] unsignedIntValue]
+    
+    unsigned cass = 0;
+    unsigned cdrm = 0;
+    unsigned hard = 0;
+    unsigned flop_5_25 = 0;
+    unsigned flop_3_5 = 0;
+
+    unsigned mask = 1;
+    for (unsigned i = 0; i < 14; ++i, mask <<= 1) {
+        
+        if (_slots_valid & mask) {
+            NSDictionary *tmp = _slot_media[i];
+            if (tmp) {
+                _(cass, tmp);
+                _(cdrm, tmp);
+                _(hard, tmp);
+                _(flop_5_25, tmp);
+                _(flop_3_5, tmp);
+            }
+        }
+    }
+    NSDictionary *tmp = _machine_media;
+    if (tmp) {
+        _(cass, tmp);
+        _(cdrm, tmp);
+        _(hard, tmp);
+        _(flop_5_25, tmp);
+        _(flop_3_5, tmp);
+    }
+    
+    [self setMedia: @{
+        @"cass": @(cass),
+        @"cdrm": @(cdrm),
+        @"hard": @(hard),
+        @"flop_5_25": @(flop_5_25),
+        @"flop_3_5": @(flop_3_5),
+    }];
+}
+
+
 @end