diff --git a/index.html b/index.html
index a771598e..28cfb6c9 100644
--- a/index.html
+++ b/index.html
@@ -545,7 +545,7 @@ function require(modname) {
 <!-- <script src="local/lzg.js"></script> -->
 <script src="gen/devices.js"></script>
 <script src="gen/cpu/MOS6502.js"></script>
-<script src="gen/machine/apple2.js"></script>
+<script src="gen/cpu/ZilogZ80.js"></script>
 
 <script>
 // submenus open on click + hover
diff --git a/src/audio.ts b/src/audio.ts
index 17b7d636..28a6f650 100644
--- a/src/audio.ts
+++ b/src/audio.ts
@@ -465,7 +465,7 @@ export var SampleAudio = function(clockfreq) {
       var inext = (ifill + 1) % bufferlist.length;
       if (inext == idrain) {
         ifill = Math.floor(idrain + nbuffers/2) % bufferlist.length;
-        //console.log('audio skipped', idrain, ifill);
+        console.log('SampleAudio: skipped buffer', idrain, ifill); // TODO
       } else {
         ifill = inext;
       }
diff --git a/src/baseplatform.ts b/src/baseplatform.ts
index 7b92550a..e12fc60e 100644
--- a/src/baseplatform.ts
+++ b/src/baseplatform.ts
@@ -59,6 +59,15 @@ export interface PlatformMetadata {
   name : string; // TODO
 }
 
+export function isDebuggable(arg:any): arg is Debuggable {
+    return typeof arg.getDebugCategories === 'function';
+}
+
+export interface Debuggable {
+  getDebugCategories?() : string[];
+  getDebugInfo?(category:string, state:EmuState) : string;
+}
+
 export interface Platform {
   start() : void;
   reset() : void;
@@ -100,8 +109,6 @@ export interface Platform {
   getOriginPC?() : number;
   newCodeAnalyzer?() : CodeAnalyzer;
 
-  getDebugCategories?() : string[];
-  getDebugInfo?(category:string, state:EmuState) : string;
 
   setRecorder?(recorder : EmuRecorder) : void;
   advance?(novideo? : boolean) : void;
@@ -1347,13 +1354,17 @@ export abstract class Base6502MachinePlatform<T extends Machine> extends BaseMac
     return disassemble6502(pc, read(pc), read(pc+1), read(pc+2));
   }
   getDebugCategories() {
-    return ['CPU','ZPRAM','Stack'];
+    if (isDebuggable(this.machine))
+      return this.machine.getDebugCategories();
+    else
+      return ['CPU','ZPRAM','Stack'];
   }
   getDebugInfo(category:string, state:EmuState) : string {
     switch (category) {
       case 'CPU':   return cpuStateToLongString_6502(state.c);
       case 'ZPRAM': return dumpRAM(state.b||state.ram, 0x0, 0x100);
       case 'Stack': return dumpStackToString(<Platform><any>this, state.b||state.ram, 0x100, 0x1ff, 0x100+state.c.SP, 0x20);
+      default: return isDebuggable(this.machine) && this.machine.getDebugInfo(category, state);
     }
   }
 
diff --git a/src/cpu/MOS6502.ts b/src/cpu/MOS6502.ts
index ee058a56..a28a036f 100644
--- a/src/cpu/MOS6502.ts
+++ b/src/cpu/MOS6502.ts
@@ -1880,12 +1880,16 @@ var _MOS6502 = function() {
       };
     }
 
+    // only call when isPCStable() is true
     this.setNMI = function() {
       instruction = NMI();
+      T = 1;
+      PC = (PC-1) & 0xffff;
     }
-
     this.setIRQ = function() {
       instruction = IRQ();
+      T = 1;
+      PC = (PC-1) & 0xffff;
     }
 
     this.getSP = function() { return SP; }
@@ -1921,6 +1925,7 @@ export class MOS6502 implements CPU, ClockBased, SavesState<MOS6502State>, Inter
         case MOS6502Interrupts.NMI: this.cpu.setNMI(); break;
         case MOS6502Interrupts.IRQ: this.cpu.setIRQ(); break;
       }
+      this.interruptType = 0;
     }
     this.cpu.clockPulse();
   }
@@ -1936,7 +1941,13 @@ export class MOS6502 implements CPU, ClockBased, SavesState<MOS6502State>, Inter
   interrupt(itype:number) {
     this.interruptType = itype;
   }
-    getSP() {
+  NMI() {
+    this.interrupt(MOS6502Interrupts.NMI);
+  }
+  IRQ() {
+    this.interrupt(MOS6502Interrupts.IRQ);
+  }
+  getSP() {
     return this.cpu.getSP();
   }
   getPC() {
diff --git a/src/devices.ts b/src/devices.ts
index b8070848..3c325200 100644
--- a/src/devices.ts
+++ b/src/devices.ts
@@ -78,7 +78,7 @@ export interface CPU extends MemoryBusConnected, Resettable, SavesState<any> {
     isStable() : boolean;
 }
 
-export interface HasCPU {
+export interface HasCPU extends Resettable {
     cpu : CPU;
 }
 
diff --git a/src/emu.ts b/src/emu.ts
index efcd4edc..be55f831 100644
--- a/src/emu.ts
+++ b/src/emu.ts
@@ -470,8 +470,8 @@ function _metakeyflags(e) {
 
 type KeyMapFunction = (o:KeyMapEntry, key:number, code:number, flags:number) => void;
 
-export function setKeyboardFromMap(video:RasterVideo, switches:number[]|Uint8Array, map:KeyCodeMap, func?:KeyMapFunction) {
-  var handler = (key,code,flags) => {
+export function newKeyboardHandler(switches:number[]|Uint8Array, map:KeyCodeMap, func?:KeyMapFunction) {
+  return (key:number,code:number,flags:number) => {
     if (!map) {
       func(null, key, code, flags);
       return;
@@ -496,6 +496,10 @@ export function setKeyboardFromMap(video:RasterVideo, switches:number[]|Uint8Arr
       }
     }
   };
+}
+
+export function setKeyboardFromMap(video:RasterVideo, switches:number[]|Uint8Array, map:KeyCodeMap, func?:KeyMapFunction) {
+  var handler = newKeyboardHandler(switches, map, func);
   video.setKeyboardEvents(handler);
   return new ControllerPoller(map, handler);
 }
diff --git a/src/machine/apple2.ts b/src/machine/apple2.ts
index bac5cda8..2998170a 100644
--- a/src/machine/apple2.ts
+++ b/src/machine/apple2.ts
@@ -30,7 +30,7 @@ interface AppleIIState extends AppleIIStateBase, AppleIIControlsState {
   grswitch : number;
 }
 
-export class AppleII implements HasCPU, Bus, Resettable, RasterFrameBased, SampledAudioSource, AcceptsROM,
+export class AppleII implements HasCPU, Bus, RasterFrameBased, SampledAudioSource, AcceptsROM,
   AppleIIStateBase, SavesState<AppleIIState>, AcceptsInput<AppleIIControlsState> {
 
   ram = new Uint8Array(0x13000); // 64K + 16K LC RAM - 4K hardware + 12K ROM
@@ -55,7 +55,6 @@ export class AppleII implements HasCPU, Bus, Resettable, RasterFrameBased, Sampl
   bank2wroffset=0;
 
   constructor() {
-    // ROM
     this.rom = new lzgmini().decode(APPLEIIGO_LZG);
     this.ram.set(this.rom, 0xd000);
     this.ram[0xbf00] = 0x4c; // fake DOS detect for C
diff --git a/src/machine/atari7800.ts b/src/machine/atari7800.ts
new file mode 100644
index 00000000..31fcc1d5
--- /dev/null
+++ b/src/machine/atari7800.ts
@@ -0,0 +1,665 @@
+"use strict";
+
+import { MOS6502, MOS6502State } from "../cpu/MOS6502";
+import { Bus, RasterFrameBased, SavesState, AcceptsROM, AcceptsInput, noise, Resettable, SampledAudioSource, SampledAudioSink, HasCPU } from "../devices";
+import { KeyFlags } from "../emu"; // TODO
+import { hex, lzgmini, stringToByteArray, lpad, rpad, rgb2bgr } from "../util";
+
+import { newAddressDecoder, padBytes, Keys, makeKeycodeMap, dumpRAM, EmuHalt, newKeyboardHandler } from "../emu";
+import { MasterAudio, POKEYDeviceChannel } from "../audio";
+
+// https://atarihq.com/danb/a7800.shtml
+// https://atarihq.com/danb/files/maria_r1.txt
+// https://sites.google.com/site/atari7800wiki/
+
+interface Atari7800StateBase {
+  ram : Uint8Array;
+  regs6532 : Uint8Array;
+}
+
+interface Atari7800ControlsState {
+  in : Uint8Array;
+}
+
+interface Atari7800State extends Atari7800StateBase, Atari7800ControlsState {
+  c : MOS6502State;
+  tia : {
+    regs : Uint8Array,
+  },
+  maria : {
+    regs : Uint8Array,
+    offset,dll,dlstart : number;
+    dli,h16,h8 : boolean;
+    
+  },
+}
+
+const SWCHA = 0;
+const SWCHB = 2;
+const INPT0 = 8;
+
+const Atari7800_KEYCODE_MAP = makeKeycodeMap([
+  [Keys.A,        INPT0+0, 0x80],
+  [Keys.B,        INPT0+1, 0x80],
+  [Keys.SELECT,   SWCHB, -0x02],
+  [Keys.START,    SWCHB, -0x01],
+  [Keys.UP,       SWCHA, -0x10],
+  [Keys.DOWN,     SWCHA, -0x20],
+  [Keys.LEFT,     SWCHA, -0x40],
+  [Keys.RIGHT,    SWCHA, -0x80],
+  
+  [Keys.P2_A,     INPT0+2, 0x80],
+  [Keys.P2_B,     INPT0+3, 0x80],
+  //[Keys.P2_SELECT, 1, 2],
+  //[Keys.P2_START,  1, 3],
+  [Keys.P2_UP,     SWCHA, -0x01],
+  [Keys.P2_DOWN,   SWCHA, -0x02],
+  [Keys.P2_LEFT,   SWCHA, -0x04],
+  [Keys.P2_RIGHT,  SWCHA, -0x08],
+]);
+
+// http://www.ataripreservation.org/websites/freddy.offenga/megazine/ISSUE5-PALNTSC.html
+// http://7800.8bitdev.org/index.php/7800_Software_Guide#APPENDIX_4:_FRAME_TIMING
+const CLK = 3579545;
+const cpuFrequency = 1789772;
+const linesPerFrame = 262;
+const numVisibleLines = 258-16;
+const colorClocksPerLine = 454; // 456?
+const colorClocksPreDMA = 28;
+const romLength = 0xc000;
+
+// TIA chip
+
+class TIA {
+  regs = new Uint8Array(0x20);
+  
+  reset() {
+    this.regs.fill(0);
+  }
+  read(a : number) : number {
+    return this.regs[a] | 0;
+  }
+  write(a : number, v : number) {
+    this.regs[a] = v;
+  }
+  saveState() {
+    return {
+      regs: this.regs.slice(0)
+    };
+  }
+  loadState(s) {
+    for (let i=0; i<32; i++)
+      this.write(i, s.regs[i]);
+  }
+  static stateToLongString(state) : string {
+    let s = "";
+    s += dumpRAM(state.regs, 0, 32);
+    return s;
+  }
+}
+
+// MARIA chip
+
+class MARIA {
+  bus : Bus;
+  cycles : number = 0;
+  regs = new Uint8Array(0x20);
+  offset : number = -1;
+  dll : number = 0;
+  dlstart : number = 0;
+  dli : boolean = false;
+  h16 : boolean = false;
+  h8 : boolean = false;
+  pixels = new Uint8Array(320);
+  WSYNC : number = 0;
+
+  reset() {
+    this.regs.fill(0);
+    // TODO?
+  }
+  read(a : number) : number {
+    return this.regs[a] | 0;
+  }
+  write(a : number, v : number) {
+    this.regs[a] = v;
+    if (a == 0x04) this.WSYNC++;
+    //console.log(hex(a), '=', hex(v));
+  }
+  saveState() {
+    return {
+      regs: this.regs.slice(0),
+      offset: this.offset,
+      dll: this.dll,
+      dlstart: this.dlstart,
+      dli: this.dli,
+      h16: this.h16,
+      h8: this.h8,
+    };
+  }
+  loadState(s) {
+    for (let i=0; i<32; i++)
+      this.write(i, s.regs[i]|0);
+    this.offset = s.offset|0;
+    this.dll = s.dll|0;
+    this.dlstart = s.dlstart|0;
+    this.dli = !!s.dli;
+    this.h16 = !!s.h16;
+    this.h8 = !!s.h8;
+  }
+  isDMAEnabled() {
+    return (this.regs[0x1c] & 0x60) == 0x40;
+  }
+  getDLLStart() {
+    return (this.regs[0x0c] << 8) + this.regs[0x10];
+  }
+  getCharBaseAddress() {
+    return (this.regs[0x14] << 8) + this.offset;
+  }
+  setVBLANK(b : boolean) {
+    if (b) {
+      this.regs[0x08] |= 0x80;
+      this.offset = -1;
+      this.dll = this.getDLLStart();
+      this.dli = this.bus && (this.bus.read(this.dll) & 0x80) != 0; // if DLI on first zone
+    } else {
+      this.regs[0x08] &= ~0x80;
+    }
+  }
+  readDLLEntry(bus) {
+    //this.profiler && this.profiler.logRead(this.dll);
+    let x = bus.read(this.dll);
+    this.offset = (x & 0xf);
+    this.h16 = (x & 0x40) != 0;
+    this.h8  = (x & 0x20) != 0;
+    this.dlstart = (bus.read(this.dll+1)<<8) + bus.read(this.dll+2);
+    //console.log(hex(this.dll,4), this.offset, hex(this.dlstart,4));
+    this.dll = (this.dll + 3) & 0xffff; // TODO: can also only cross 1 page?
+    this.dli = (bus.read(this.dll) & 0x80) != 0; // DLI flag is from next DLL entry
+  }
+  isHoley(a : number) : boolean {
+    if (a & 0x8000) {
+      if (this.h16 && (a & 0x1000)) return true;
+      if (this.h8  && (a & 0x800))  return true;
+    }
+    return false;
+  }
+  readDMA(a : number) : number {
+    if (this.isHoley(a))
+      return 0;
+    else {
+      this.cycles += 3;
+      //this.profiler && this.profiler.logRead(a);
+      return this.bus.read(a);
+    }
+  }
+  doDMA(platform : Atari7800) {
+    let bus = this.bus = platform;
+    //let profiler = this.profiler = platform.profiler;
+    this.cycles = 0;
+    this.pixels.fill(this.regs[0x0]);
+    if (this.isDMAEnabled()) {
+      this.cycles += 16;
+      // time for a new DLL entry?
+      if (this.offset < 0) {
+        this.readDLLEntry(bus);
+      }
+      // read the DL (only can span two pages)
+      let dlhi = this.dlstart & 0xff00;
+      let dlofs = this.dlstart & 0xff;
+      do {
+        // read DL entry
+        //profiler && profiler.logRead(dlhi + ((dlofs+0) & 0x1ff));
+        let b0 = bus.read(dlhi + ((dlofs+0) & 0x1ff));
+        let b1 = bus.read(dlhi + ((dlofs+1) & 0x1ff));
+        if (b1 == 0) break; // end of DL
+        let b2 = bus.read(dlhi + ((dlofs+2) & 0x1ff));
+        let b3 = bus.read(dlhi + ((dlofs+3) & 0x1ff));
+        let indirect = false;
+        // extended header?
+        if ((b1 & 31) == 0) {
+          var pal = b3 >> 5;
+          var width = 32 - (b3 & 31);
+          var xpos = bus.read(dlhi + ((dlofs+4) & 0x1ff));
+          var writemode = b1 & 0x80;
+          indirect = (b1 & 0x20) != 0;
+          dlofs += 5;
+          this.cycles += 10;
+        } else {
+          // direct mode
+          var xpos = b3;
+          var pal = b1 >> 5;
+          var width = 32 - (b1 & 31);
+          var writemode = 0;
+          dlofs += 4;
+          this.cycles += 8;
+        }
+        let gfxadr = b0 + (((b2 + (indirect?0:this.offset)) & 0xff) << 8);
+        xpos *= 2;
+        // copy graphics data (direct)
+        let readmode = (this.regs[0x1c] & 0x3) + (writemode?4:0);
+        // double bytes?
+        let dbl = indirect && (this.regs[0x1c] & 0x10) != 0;
+        if (dbl) { width *= 2; }
+        //if (this.offset == 0) console.log(hex(dla,4), hex(gfxadr,4), xpos, width, pal, readmode);
+        for (var i=0; i<width; i++) {
+          let data = this.readDMA( dbl ? (gfxadr+(i>>1)) : (gfxadr+i) );
+          if (indirect) {
+            let indadr = ((this.regs[0x14] + this.offset) << 8) + data;
+            if (dbl && (i&1)) indadr++;
+            data = this.readDMA(indadr);
+          }
+          // TODO: more modes
+          switch (readmode) {
+            case 0:	// 160 A/B
+              for (let j=0; j<4; j++) {
+                var col = (data >> 6) & 3;
+                if (col > 0) {
+                  this.pixels[xpos] = this.pixels[xpos+1] = this.regs[(pal<<2) + col];
+                }
+                data <<= 2;
+                xpos = (xpos + 2) & 0x1ff;
+              }
+              break;
+            case 2:	// 320 B/D (TODO?)
+            case 3:	// 320 A/C
+              for (let j=0; j<8; j++) {
+                var col = (data & 128) ? 1 : 0;
+                if (col > 0) {
+                  this.pixels[xpos] = this.regs[(pal<<2) + col];
+                }
+                data <<= 1;
+                xpos = (xpos + 1) & 0x1ff;
+              }
+              break;
+          }
+        }
+      } while (this.cycles < colorClocksPerLine); // TODO?
+      // decrement offset
+      this.offset -= 1;
+    }
+    return this.cycles;
+  }
+  doInterrupt() : boolean {
+    if (this.dli && this.offset < 0) {
+      this.dli = false;
+      return true;
+    } else
+      return false;
+    //return this.dli;// && this.offset == 1;
+  }
+  static stateToLongString(state) : string {
+    let s = "";
+    s += dumpRAM(state.regs, 0, 32);
+    s += "\n   DLL: $" + hex((state.regs[0x0c] << 8) + state.regs[0x10],4) + " @ $" + hex(state.dll,4);
+    s += "\n    DL: $" + hex(state.dlstart,4);
+    s += "\nOffset:  " + state.offset;
+    s += "\n   DLI?  " + state.dli;
+    return s;
+  }
+}
+
+// Atari 7800
+
+export class Atari7800 implements HasCPU, Bus, RasterFrameBased, SampledAudioSource, AcceptsROM,
+  Atari7800StateBase, SavesState<Atari7800State>, AcceptsInput<Atari7800ControlsState> {
+
+  cpu : MOS6502;
+  ram : Uint8Array = new Uint8Array(0x1000);
+  rom : Uint8Array;
+  bios : Uint8Array;
+  inputs = new Uint8Array(16);
+  regs6532 = new Uint8Array(4);
+  scanline : number = 0;
+  tia : TIA = new TIA();
+  maria : MARIA = new MARIA();
+  pokey1; //TODO: type
+  
+  pixels : Uint32Array;
+  audio : SampledAudioSink;
+  handler; // TODO: type, or use ControllerPoller
+  
+  read  : (a:number) => number;
+  write : (a:number, v:number) => void;
+
+  constructor() {
+    this.cpu = new MOS6502();
+    this.read = newAddressDecoder([
+        [0x0008, 0x000d,   0x0f, (a) => { return this.readInput(a); }],
+        [0x0000, 0x001f,   0x1f, (a) => { return this.tia.read(a); }],
+        [0x0020, 0x003f,   0x1f, (a) => { return this.maria.read(a); /*this.profiler && this.profiler.logRead(a+0x20);*/  }],
+        [0x0040, 0x00ff,   0xff, (a) => { return this.ram[a + 0x800]; }],
+        [0x0100, 0x013f,   0xff, (a) => { return this.read(a); }], // shadow
+        [0x0140, 0x01ff,  0x1ff, (a) => { return this.ram[a + 0x800]; }],
+        [0x0280, 0x02ff,    0x3, (a) => { return this.inputs[a]; }],
+        [0x1800, 0x27ff, 0xffff, (a) => { return this.ram[a - 0x1800]; }],
+        [0x2800, 0x3fff,  0x7ff, (a) => { return this.read(a | 0x2000); }], // shadow
+        [0x4000, 0xffff, 0xffff, (a) => { return this.rom ? this.rom[a - 0x4000] : 0; }],
+        [0x0000, 0xffff, 0xffff, (a) => { return 0; }], // TODO
+      ]);
+    this.write = newAddressDecoder([
+        [0x0015, 0x001A,   0x1f, (a,v) => { this.pokey1.setTIARegister(a, v); }],
+        [0x0000, 0x001f,   0x1f, (a,v) => { this.tia.write(a,v); /*this.profiler && this.profiler.logWrite(a);*/ }],
+        [0x0020, 0x003f,   0x1f, (a,v) => { this.maria.write(a,v); /*this.profiler && this.profiler.logWrite(a+0x20);*/ }],
+        [0x0040, 0x00ff,   0xff, (a,v) => { this.ram[a + 0x800] = v; }],
+        [0x0100, 0x013f,   0xff, (a,v) => { this.write(a,v); }], // shadow
+        [0x0140, 0x01ff,  0x1ff, (a,v) => { this.ram[a + 0x800] = v; }],
+        [0x0280, 0x02ff,    0x3, (a,v) => { this.regs6532[a] = v; /*TODO*/ }],
+        [0x1800, 0x27ff, 0xffff, (a,v) => { this.ram[a - 0x1800] = v; }],
+        [0x2800, 0x3fff,  0x7ff, (a,v) => { this.write(a | 0x2000, v); }], // shadow
+        [0xbfff, 0xbfff, 0xffff, (a,v) => { }], // TODO: bank switching?
+        [0x0000, 0xffff, 0xffff, (a,v) => { throw new EmuHalt("Write @ " + hex(a,4) + " " + hex(v,2)); }],
+      ]);
+    this.cpu.connectMemoryBus(this);
+    this.handler = newKeyboardHandler(this.inputs, Atari7800_KEYCODE_MAP);
+    this.pokey1 = new POKEYDeviceChannel();
+    this.pokey1.setBufferLength(4);
+    this.pokey1.setSampleRate(this.getAudioParams().sampleRate);
+  }
+  
+  readConst(a) { return this.read(a); } //TODO?
+
+  readInput(a:number) : number {
+    //this.profiler && this.profiler.logRead(a+0x20);
+    switch (a) {
+      case 0xc: return ~this.inputs[0x8] & 0x80; //INPT4
+      case 0xd: return ~this.inputs[0x9] & 0x80; //INPT5
+      default: return this.inputs[a]|0;
+    }
+  }
+
+  getVideoParams() {
+    return {width:320, height:numVisibleLines};
+  }
+  getAudioParams() {
+    return {sampleRate:linesPerFrame*60*2, stereo:false};
+  }
+  connectVideo(pixels:Uint32Array) {
+    this.pixels = pixels;
+  }
+  connectAudio(audio:SampledAudioSink) {
+    this.audio = audio;
+  }
+
+    //TODO this.bios = new Uint8Array(0x1000);
+    // TODO: TIA access wastes a cycle
+
+  setInput(key:number, code:number, flags:number) : void {
+    this.handler(key,code,flags);
+  }
+  
+  advanceFrame(maxClocks, debugCond) : number {
+    var idata = this.pixels;
+    var iofs = 0;
+    var rgb;
+    var mariaClocks = colorClocksPreDMA; // 7 CPU cycles until DMA
+    var frameClocks = 0;
+    //console.log(hex(this.cpu.getPC()), hex(this.maria.dll));
+    // visible lines
+    for (var sl=0; sl<linesPerFrame; sl++) {
+      this.scanline = sl;
+      var visible = sl < numVisibleLines;
+      this.maria.setVBLANK(!visible);
+      // iterate CPU with free clocks
+      while (mariaClocks > 0) {
+        // wait for WSYNC? (end of line)
+        if (this.maria.WSYNC) {
+          if (mariaClocks >= colorClocksPreDMA) {
+            this.maria.WSYNC--;
+            mariaClocks = colorClocksPreDMA; // 7 CPU cycles until DMA
+          } else {
+            break;
+          }
+        }
+        // next CPU clock
+        mariaClocks -= 4;
+        if (debugCond && debugCond()) {
+          debugCond = null;
+          sl = 999;
+          break;
+        }
+        this.cpu.advanceClock();
+      }
+      mariaClocks += colorClocksPerLine;
+      // is this scanline visible?
+      if (visible) {
+        // do DMA for scanline?
+        mariaClocks -= this.maria.doDMA(this);
+        // copy line to frame buffer
+        if (idata) {
+          for (var i=0; i<320; i++) {
+            idata[iofs++] = COLORS_RGBA[this.maria.pixels[i]];
+          }
+        }
+      }
+      // do interrupt? (if visible or before 1st scanline)
+      if ((visible || sl == linesPerFrame-1) && this.maria.doInterrupt()) {
+        //this.profiler && this.profiler.logInterrupt(0);
+        this.cpu.NMI();
+    //console.log("NMI", hex(this.cpu.getPC()), hex(this.maria.dll));
+      }
+      // audio
+      if (this.audio) {
+        const audioGain = 1.0 / 16384;
+        this.pokey1.generate(4);
+        this.audio.feedSample(this.pokey1.getBuffer()[0] * audioGain, 1);
+        this.audio.feedSample(this.pokey1.getBuffer()[2] * audioGain, 1);
+      }
+    }
+    // update video frame
+    /*
+    if (!novideo) {
+      // set background/border color
+      // TODO let bkcol = this.maria.regs[0x0];
+      // TODO $(this.video.canvas).css('background-color', COLORS_WEB[bkcol]);
+    }
+    */
+    return frameClocks;
+  }
+
+  loadROM(data) {
+    if (data.length == 0xc080) data = data.slice(0x80); // strip header
+    this.rom = padBytes(data, romLength, true);
+  }
+/*
+  loadBIOS(data) {
+    this.bios = padBytes(data, 0x1000);
+  }
+*/
+  reset() {
+    this.cpu.reset();
+    this.tia.reset();
+    this.maria.reset();
+    this.inputs.fill(0x0);
+    this.inputs[SWCHA] = 0xff;
+    this.inputs[SWCHB] = 1+2+8;
+    //this.cpu.advanceClock(); // TODO: needed for test to pass?
+  }
+
+  // TODO: don't log if profiler active
+  readAddress(addr : number) {
+    return this.read(addr) | 0;
+  }
+
+  loadState(state : Atari7800State) {
+    this.cpu.loadState(state.c);
+    this.ram.set(state.ram);
+    this.tia.loadState(state.tia);
+    this.maria.loadState(state.maria);
+    this.regs6532.set(state.regs6532);
+    this.loadControlsState(state);
+  }
+  saveState() : Atari7800State {
+    return {
+      c:this.cpu.saveState(),
+      ram:this.ram.slice(0),
+      tia:this.tia.saveState(),
+      maria:this.maria.saveState(),
+      regs6532:this.regs6532.slice(0),
+      in:this.inputs.slice(0)
+    };
+  }
+  loadControlsState(state:Atari7800ControlsState) {
+    this.inputs.set(state.in);
+  }
+  saveControlsState() : Atari7800ControlsState {
+    return {
+      in:this.inputs.slice(0)
+    };
+  }
+
+  getRasterScanline() {
+    return this.scanline;
+  }
+
+  getDebugCategories() {
+    return ['CPU','Stack','TIA','MARIA'];
+  }
+  getDebugInfo(category, state) {
+    switch (category) {
+      case 'TIA': return TIA.stateToLongString(state.tia);
+      case 'MARIA': return MARIA.stateToLongString(state.maria) + "\nScanline: " + this.scanline;
+      //default: return super.getDebugInfo(category, state);
+    }
+  }
+}
+
+///
+
+const ATARI_NTSC_RGB = [
+    0x000000,		// 00
+    0x404040,		// 02
+    0x6c6c6c,		// 04
+    0x909090,		// 06
+    0xb0b0b0,		// 08
+    0xc8c8c8,		// 0A
+    0xdcdcdc,		// 0C
+    0xf4f4f4,		// 0E
+    0x004444,		// 10
+    0x106464,		// 12
+    0x248484,		// 14
+    0x34a0a0,		// 16
+    0x40b8b8,		// 18
+    0x50d0d0,		// 1A
+    0x5ce8e8,		// 1C
+    0x68fcfc,		// 1E
+    0x002870,		// 20
+    0x144484,		// 22
+    0x285c98,		// 24
+    0x3c78ac,		// 26
+    0x4c8cbc,		// 28
+    0x5ca0cc,		// 2A
+    0x68b4dc,		// 2C
+    0x78c8ec,		// 2E
+    0x001884,		// 30
+    0x183498,		// 32
+    0x3050ac,		// 34
+    0x4868c0,		// 36
+    0x5c80d0,		// 38
+    0x7094e0,		// 3A
+    0x80a8ec,		// 3C
+    0x94bcfc,		// 3E
+    0x000088,		// 40
+    0x20209c,		// 42
+    0x3c3cb0,		// 44
+    0x5858c0,		// 46
+    0x7070d0,		// 48
+    0x8888e0,		// 4A
+    0xa0a0ec,		// 4C
+    0xb4b4fc,		// 4E
+    0x5c0078,		// 50
+    0x74208c,		// 52
+    0x883ca0,		// 54
+    0x9c58b0,		// 56
+    0xb070c0,		// 58
+    0xc084d0,		// 5A
+    0xd09cdc,		// 5C
+    0xe0b0ec,		// 5E
+    0x780048,		// 60
+    0x902060,		// 62
+    0xa43c78,		// 64
+    0xb8588c,		// 66
+    0xcc70a0,		// 68
+    0xdc84b4,		// 6A
+    0xec9cc4,		// 6C
+    0xfcb0d4,		// 6E
+    0x840014,		// 70
+    0x982030,		// 72
+    0xac3c4c,		// 74
+    0xc05868,		// 76
+    0xd0707c,		// 78
+    0xe08894,		// 7A
+    0xeca0a8,		// 7C
+    0xfcb4bc,		// 7E
+    0x880000,		// 80
+    0x9c201c,		// 82
+    0xb04038,		// 84
+    0xc05c50,		// 86
+    0xd07468,		// 88
+    0xe08c7c,		// 8A
+    0xeca490,		// 8C
+    0xfcb8a4,		// 8E
+    0x7c1800,		// 90
+    0x90381c,		// 92
+    0xa85438,		// 94
+    0xbc7050,		// 96
+    0xcc8868,		// 98
+    0xdc9c7c,		// 9A
+    0xecb490,		// 9C
+    0xfcc8a4,		// 9E
+    0x5c2c00,		// A0
+    0x784c1c,		// A2
+    0x906838,		// A4
+    0xac8450,		// A6
+    0xc09c68,		// A8
+    0xd4b47c,		// AA
+    0xe8cc90,		// AC
+    0xfce0a4,		// AE
+    0x2c3c00,		// B0
+    0x485c1c,		// B2
+    0x647c38,		// B4
+    0x809c50,		// B6
+    0x94b468,		// B8
+    0xacd07c,		// BA
+    0xc0e490,		// BC
+    0xd4fca4,		// BE
+    0x003c00,		// C0
+    0x205c20,		// C2
+    0x407c40,		// C4
+    0x5c9c5c,		// C6
+    0x74b474,		// C8
+    0x8cd08c,		// CA
+    0xa4e4a4,		// CC
+    0xb8fcb8,		// CE
+    0x003814,		// D0
+    0x1c5c34,		// D2
+    0x387c50,		// D4
+    0x50986c,		// D6
+    0x68b484,		// D8
+    0x7ccc9c,		// DA
+    0x90e4b4,		// DC
+    0xa4fcc8,		// DE
+    0x00302c,		// E0
+    0x1c504c,		// E2
+    0x347068,		// E4
+    0x4c8c84,		// E6
+    0x64a89c,		// E8
+    0x78c0b4,		// EA
+    0x88d4cc,		// EC
+    0x9cece0,		// EE
+    0x002844,		// F0
+    0x184864,		// F2
+    0x306884,		// F4
+    0x4484a0,		// F6
+    0x589cb8,		// F8
+    0x6cb4d0,		// FA
+    0x7ccce8,		// FC
+    0x8ce0fc		// FE
+];
+
+var COLORS_RGBA = new Uint32Array(256);
+var COLORS_WEB = [];
+for (var i=0; i<256; i++) {
+  COLORS_RGBA[i] = ATARI_NTSC_RGB[i>>1] | 0xff000000;
+  COLORS_WEB[i] = "#"+hex(rgb2bgr(ATARI_NTSC_RGB[i>>1]),6);
+}
+
diff --git a/src/platform/apple2.ts b/src/platform/apple2.ts
index 2075727d..1c12c92f 100644
--- a/src/platform/apple2.ts
+++ b/src/platform/apple2.ts
@@ -5,8 +5,6 @@ import { PLATFORMS, RAM, newAddressDecoder, padBytes, noise, setKeyboardFromMap,
 import { hex, lzgmini } from "../util";
 import { SampleAudio, SampledAudio } from "../audio";
 
-declare var jt; // 6502
-
 const APPLE2_PRESETS = [
   {id:'sieve.c', name:'Sieve'},
   {id:'keyboardtest.c', name:'Keyboard Test'},
diff --git a/src/platform/atari7800.ts b/src/platform/atari7800.ts
index 5c436181..6a57bcb9 100644
--- a/src/platform/atari7800.ts
+++ b/src/platform/atari7800.ts
@@ -1,659 +1,22 @@
 "use strict";
 
-import { Platform, Base6502Platform, BaseMAMEPlatform, getOpcodeMetadata_6502, getToolForFilename_6502 } from "../baseplatform";
-import { PLATFORMS, RAM, newAddressDecoder, padBytes, noise, setKeyboardFromMap, AnimationTimer, RasterVideo, Keys, makeKeycodeMap, dumpRAM, getMousePos, EmuHalt } from "../emu";
-import { hex, lzgmini, stringToByteArray, lpad, rpad, rgb2bgr } from "../util";
-import { MasterAudio, POKEYDeviceChannel, newPOKEYAudio } from "../audio";
-
-declare var jt; // for 6502
-
-// https://atarihq.com/danb/a7800.shtml
-// https://atarihq.com/danb/files/maria_r1.txt
-// https://sites.google.com/site/atari7800wiki/
+import { MOS6502 } from "../cpu/MOS6502";
+import { Atari7800 } from "../machine/atari7800";
+import { Platform, Base6502MachinePlatform } from "../baseplatform";
+import { PLATFORMS } from "../emu";
 
 var Atari7800_PRESETS = [
   {id:'sprites.dasm', name:'Sprites (ASM)'},
 ];
 
-const SWCHA = 0;
-const SWCHB = 2;
-const INPT0 = 8;
+class Atari7800Platform extends Base6502MachinePlatform<Atari7800> implements Platform {
 
-const Atari7800_KEYCODE_MAP = makeKeycodeMap([
-  [Keys.A,        INPT0+0, 0x80],
-  [Keys.B,        INPT0+1, 0x80],
-  [Keys.SELECT,   SWCHB, -0x02],
-  [Keys.START,    SWCHB, -0x01],
-  [Keys.UP,       SWCHA, -0x10],
-  [Keys.DOWN,     SWCHA, -0x20],
-  [Keys.LEFT,     SWCHA, -0x40],
-  [Keys.RIGHT,    SWCHA, -0x80],
-  
-  [Keys.P2_A,     INPT0+2, 0x80],
-  [Keys.P2_B,     INPT0+3, 0x80],
-  //[Keys.P2_SELECT, 1, 2],
-  //[Keys.P2_START,  1, 3],
-  [Keys.P2_UP,     SWCHA, -0x01],
-  [Keys.P2_DOWN,   SWCHA, -0x02],
-  [Keys.P2_LEFT,   SWCHA, -0x04],
-  [Keys.P2_RIGHT,  SWCHA, -0x08],
-]);
+  newMachine()          { return new Atari7800(); }
+  getPresets()          { return Atari7800_PRESETS; }
+  getDefaultExtension() { return ".c"; };
+  readAddress(a)        { return this.machine.readConst(a); }
+  // TODO loadBios(bios)	{ this.machine.loadBIOS(a); }
 
-// http://www.ataripreservation.org/websites/freddy.offenga/megazine/ISSUE5-PALNTSC.html
-// http://7800.8bitdev.org/index.php/7800_Software_Guide#APPENDIX_4:_FRAME_TIMING
-const CLK = 3579545;
-const cpuFrequency = 1789772;
-const linesPerFrame = 262;
-const numVisibleLines = 258-16;
-const colorClocksPerLine = 454; // 456?
-const colorClocksPreDMA = 28;
-const romLength = 0xc000;
-
-// TIA chip
-
-class TIA {
-  regs = new Uint8Array(0x20);
-  
-  reset() {
-    this.regs.fill(0);
-  }
-  read(a : number) : number {
-    return this.regs[a] | 0;
-  }
-  write(a : number, v : number) {
-    this.regs[a] = v;
-  }
-  saveState() {
-    return {
-      regs: this.regs.slice(0)
-    };
-  }
-  loadState(s) {
-    for (let i=0; i<32; i++)
-      this.write(i, s.regs[i]);
-  }
-  static stateToLongString(state) : string {
-    let s = "";
-    s += dumpRAM(state.regs, 0, 32);
-    return s;
-  }
-}
-
-// MARIA chip
-
-class MARIA {
-  bus;
-  profiler;
-  cycles : number = 0;
-  regs = new Uint8Array(0x20);
-  offset : number = -1;
-  dll : number = 0;
-  dlstart : number = 0;
-  dli : boolean = false;
-  h16 : boolean = false;
-  h8 : boolean = false;
-  pixels = new Uint8Array(320);
-  WSYNC : number = 0;
-
-  reset() {
-    this.regs.fill(0);
-  }
-  read(a : number) : number {
-    return this.regs[a] | 0;
-  }
-  write(a : number, v : number) {
-    this.regs[a] = v;
-    if (a == 0x04) this.WSYNC++;
-    //console.log(hex(a), '=', hex(v));
-  }
-  saveState() {
-    return {
-      regs: this.regs.slice(0),
-      offset: this.offset,
-      dll: this.dll,
-      dlstart: this.dlstart,
-      dli: this.dli,
-      h16: this.h16,
-      h8: this.h8,
-    };
-  }
-  loadState(s) {
-    for (let i=0; i<32; i++)
-      this.write(i, s.regs[i]);
-    this.offset = s.offset;
-    this.dll = s.dll;
-    this.dlstart = s.dlstart;
-    this.dli = s.dli;
-    this.h16 = s.h16;
-    this.h8 = s.h8;
-  }
-  isDMAEnabled() {
-    return (this.regs[0x1c] & 0x60) == 0x40;
-  }
-  getDLLStart() {
-    return (this.regs[0x0c] << 8) + this.regs[0x10];
-  }
-  getCharBaseAddress() {
-    return (this.regs[0x14] << 8) + this.offset;
-  }
-  setVBLANK(b : boolean) {
-    if (b) {
-      this.regs[0x08] |= 0x80;
-      this.offset = -1;
-      this.dll = this.getDLLStart();
-      this.dli = this.bus && (this.bus.read(this.dll) & 0x80) != 0; // if DLI on first zone
-    } else {
-      this.regs[0x08] &= ~0x80;
-    }
-  }
-  readDLLEntry(bus) {
-    this.profiler && this.profiler.logRead(this.dll);
-    let x = bus.read(this.dll);
-    this.offset = (x & 0xf);
-    this.h16 = (x & 0x40) != 0;
-    this.h8  = (x & 0x20) != 0;
-    this.dlstart = (bus.read(this.dll+1)<<8) + bus.read(this.dll+2);
-    //console.log(hex(this.dll,4), this.offset, hex(this.dlstart,4));
-    this.dll = (this.dll + 3) & 0xffff; // TODO: can also only cross 1 page?
-    this.dli = (bus.read(this.dll) & 0x80) != 0; // DLI flag is from next DLL entry
-  }
-  isHoley(a : number) : boolean {
-    if (a & 0x8000) {
-      if (this.h16 && (a & 0x1000)) return true;
-      if (this.h8  && (a & 0x800))  return true;
-    }
-    return false;
-  }
-  readDMA(a : number) : number {
-    if (this.isHoley(a))
-      return 0;
-    else {
-      this.cycles += 3;
-      //this.profiler && this.profiler.logRead(a);
-      return this.bus.read(a);
-    }
-  }
-  doDMA(platform : Atari7800Platform) {
-    let bus = this.bus = platform.bus;
-    let profiler = this.profiler = platform.profiler;
-    this.cycles = 0;
-    this.pixels.fill(this.regs[0x0]);
-    if (this.isDMAEnabled()) {
-      this.cycles += 16;
-      // time for a new DLL entry?
-      if (this.offset < 0) {
-        this.readDLLEntry(bus);
-      }
-      // read the DL (only can span two pages)
-      let dlhi = this.dlstart & 0xff00;
-      let dlofs = this.dlstart & 0xff;
-      do {
-        // read DL entry
-        profiler && profiler.logRead(dlhi + ((dlofs+0) & 0x1ff));
-        let b0 = bus.read(dlhi + ((dlofs+0) & 0x1ff));
-        let b1 = bus.read(dlhi + ((dlofs+1) & 0x1ff));
-        if (b1 == 0) break; // end of DL
-        let b2 = bus.read(dlhi + ((dlofs+2) & 0x1ff));
-        let b3 = bus.read(dlhi + ((dlofs+3) & 0x1ff));
-        let indirect = false;
-        // extended header?
-        if ((b1 & 31) == 0) {
-          var pal = b3 >> 5;
-          var width = 32 - (b3 & 31);
-          var xpos = bus.read(dlhi + ((dlofs+4) & 0x1ff));
-          var writemode = b1 & 0x80;
-          indirect = (b1 & 0x20) != 0;
-          dlofs += 5;
-          this.cycles += 10;
-        } else {
-          // direct mode
-          var xpos = b3;
-          var pal = b1 >> 5;
-          var width = 32 - (b1 & 31);
-          var writemode = 0;
-          dlofs += 4;
-          this.cycles += 8;
-        }
-        let gfxadr = b0 + (((b2 + (indirect?0:this.offset)) & 0xff) << 8);
-        xpos *= 2;
-        // copy graphics data (direct)
-        let readmode = (this.regs[0x1c] & 0x3) + (writemode?4:0);
-        // double bytes?
-        let dbl = indirect && (this.regs[0x1c] & 0x10) != 0;
-        if (dbl) { width *= 2; }
-        //if (this.offset == 0) console.log(hex(dla,4), hex(gfxadr,4), xpos, width, pal, readmode);
-        for (var i=0; i<width; i++) {
-          let data = this.readDMA( dbl ? (gfxadr+(i>>1)) : (gfxadr+i) );
-          if (indirect) {
-            let indadr = ((this.regs[0x14] + this.offset) << 8) + data;
-            if (dbl && (i&1)) indadr++;
-            data = this.readDMA(indadr);
-          }
-          // TODO: more modes
-          switch (readmode) {
-            case 0:	// 160 A/B
-              for (let j=0; j<4; j++) {
-                var col = (data >> 6) & 3;
-                if (col > 0) {
-                  this.pixels[xpos] = this.pixels[xpos+1] = this.regs[(pal<<2) + col];
-                }
-                data <<= 2;
-                xpos = (xpos + 2) & 0x1ff;
-              }
-              break;
-            case 2:	// 320 B/D (TODO?)
-            case 3:	// 320 A/C
-              for (let j=0; j<8; j++) {
-                var col = (data & 128) ? 1 : 0;
-                if (col > 0) {
-                  this.pixels[xpos] = this.regs[(pal<<2) + col];
-                }
-                data <<= 1;
-                xpos = (xpos + 1) & 0x1ff;
-              }
-              break;
-          }
-        }
-      } while (this.cycles < colorClocksPerLine); // TODO?
-      // decrement offset
-      this.offset -= 1;
-    }
-    return this.cycles;
-  }
-  doInterrupt() : boolean {
-    if (this.dli && this.offset < 0) {
-      this.dli = false;
-      return true;
-    } else
-      return false;
-    //return this.dli;// && this.offset == 1;
-  }
-  static stateToLongString(state) : string {
-    let s = "";
-    s += dumpRAM(state.regs, 0, 32);
-    s += "\n   DLL: $" + hex((state.regs[0x0c] << 8) + state.regs[0x10],4) + " @ $" + hex(state.dll,4);
-    s += "\n    DL: $" + hex(state.dlstart,4);
-    s += "\nOffset:  " + state.offset;
-    s += "\n   DLI?  " + state.dli;
-    return s;
-  }
-}
-
-// Atari 7800
-
-class Atari7800Platform extends Base6502Platform implements Platform {
-
-  mainElement : HTMLElement;
-  cpu;
-  ram : Uint8Array;
-  rom : Uint8Array;
-  bios : Uint8Array;
-  bus;
-  video;
-  audio;
-  timer : AnimationTimer;
-  inputs = new Uint8Array(16);
-  regs6532 = new Uint8Array(4);
-  scanline : number = 0;
-  tia : TIA = new TIA();
-  maria : MARIA = new MARIA();
-
-  constructor(mainElement : HTMLElement) {
-    super();
-    this.mainElement = mainElement;
-  }
-
-  getPresets() {
-    return Atari7800_PRESETS;
-  }
-  
-  readInput(a:number) : number {
-    this.profiler && this.profiler.logRead(a+0x20);
-    switch (a) {
-      case 0xc: return ~this.inputs[0x8] & 0x80; //INPT4
-      case 0xd: return ~this.inputs[0x9] & 0x80; //INPT5
-      default: return this.inputs[a]|0;
-    }
-  }
-
-  start() {
-    this.cpu = new jt.M6502();
-    this.ram = new Uint8Array(0x1000);
-    //this.bios = new Uint8Array(0x1000); // TODO
-    // TODO: TIA access wastes a cycle
-    this.bus = {
-      read: newAddressDecoder([
-        [0x0008, 0x000d,   0x0f, (a) => { return this.readInput(a); }],
-        [0x0000, 0x001f,   0x1f, (a) => { return this.tia.read(a); }],
-        [0x0020, 0x003f,   0x1f, (a) => { return this.maria.read(a); this.profiler && this.profiler.logRead(a+0x20);  }],
-        [0x0040, 0x00ff,   0xff, (a) => { return this.ram[a + 0x800]; }],
-        [0x0100, 0x013f,   0xff, (a) => { return this.bus.read(a); }], // shadow
-        [0x0140, 0x01ff,  0x1ff, (a) => { return this.ram[a + 0x800]; }],
-        [0x0280, 0x02ff,    0x3, (a) => { return this.inputs[a]; }],
-        [0x1800, 0x27ff, 0xffff, (a) => { return this.ram[a - 0x1800]; }],
-        [0x2800, 0x3fff,  0x7ff, (a) => { return this.bus.read(a | 0x2000); }], // shadow
-        [0x4000, 0xffff, 0xffff, (a) => { return this.rom ? this.rom[a - 0x4000] : 0; }],
-        [0x0000, 0xffff, 0xffff, (a) => { return 0; }], // TODO
-      ]),
-      write: newAddressDecoder([
-        [0x0015, 0x001A,   0x1f, (a,v) => { this.audio.pokey1.setTIARegister(a, v); }],
-        [0x0000, 0x001f,   0x1f, (a,v) => { this.tia.write(a,v); this.profiler && this.profiler.logWrite(a); }],
-        [0x0020, 0x003f,   0x1f, (a,v) => { this.maria.write(a,v); this.profiler && this.profiler.logWrite(a+0x20); }],
-        [0x0040, 0x00ff,   0xff, (a,v) => { this.ram[a + 0x800] = v; }],
-        [0x0100, 0x013f,   0xff, (a,v) => { this.bus.write(a); }], // shadow
-        [0x0140, 0x01ff,  0x1ff, (a,v) => { this.ram[a + 0x800] = v; }],
-        [0x0280, 0x02ff,    0x3, (a,v) => { this.regs6532[a] = v; /*TODO*/ }],
-        [0x1800, 0x27ff, 0xffff, (a,v) => { this.ram[a - 0x1800] = v; }],
-        [0x2800, 0x3fff,  0x7ff, (a,v) => { this.bus.write(a | 0x2000, v); }], // shadow
-        [0xbfff, 0xbfff, 0xffff, (a,v) => { }], // TODO: bank switching?
-        [0x0000, 0xffff, 0xffff, (a,v) => { throw new EmuHalt("Write @ " + hex(a,4) + " " + hex(v,2)); }],
-      ]),
-    };
-    this.cpu.connectBus(this.bus);
-    // create video/audio
-    this.video = new RasterVideo(this.mainElement, 320, numVisibleLines);
-    this.audio = newPOKEYAudio(1);
-    this.video.create();
-    setKeyboardFromMap(this.video, this.inputs, Atari7800_KEYCODE_MAP, (o,key,code,flags) => {
-      // TODO
-    });
-    this.timer = new AnimationTimer(60, this.nextFrame.bind(this));
-    // setup mouse events
-    var rasterPosBreakFn = (e) => {
-      if (e.shiftKey) {
-        var clickpos = getMousePos(e.target, e);
-        this.runEval( (c) => {
-          return (this.getRasterScanline() == (clickpos.y|0));
-        });
-      }
-    };
-    var jacanvas = $("#emulator").find("canvas");
-    jacanvas.mousedown(rasterPosBreakFn);
-  }
-  
-  advance(novideo : boolean) {
-    var idata = this.video.getFrameData();
-    var iofs = 0;
-    var debugCond = this.getDebugCallback();
-    var rgb;
-    var mariaClocks = colorClocksPreDMA; // 7 CPU cycles until DMA
-    // visible lines
-    for (var sl=0; sl<linesPerFrame; sl++) {
-      this.scanline = sl;
-      var visible = sl < numVisibleLines;
-      this.maria.setVBLANK(!visible);
-      // iterate CPU with free clocks
-      while (mariaClocks > 0) {
-        // wait for WSYNC? (end of line)
-        if (this.maria.WSYNC) {
-          if (mariaClocks >= colorClocksPreDMA) {
-            this.maria.WSYNC--;
-            mariaClocks = colorClocksPreDMA; // 7 CPU cycles until DMA
-          } else {
-            break;
-          }
-        }
-        // next CPU clock
-        mariaClocks -= 4;
-        if (debugCond && debugCond()) {
-          debugCond = null;
-          sl = 999;
-          break;
-        }
-        this.cpu.clockPulse();
-      }
-      mariaClocks += colorClocksPerLine;
-      // is this scanline visible?
-      if (visible) {
-        // do DMA for scanline?
-        mariaClocks -= this.maria.doDMA(this);
-        // copy line to frame buffer
-        for (var i=0; i<320; i++) {
-          idata[iofs++] = COLORS_RGBA[this.maria.pixels[i]];
-        }
-      }
-      // do interrupt? (if visible or before 1st scanline)
-      if ((visible || sl == linesPerFrame-1) && this.maria.doInterrupt()) {
-        this.profiler && this.profiler.logInterrupt(0);
-        mariaClocks -= this.cpu.setNMIAndWait() * 4;
-      }
-    }
-    // update video frame
-    if (!novideo) {
-      this.video.updateFrame();
-      // set background/border color
-      let bkcol = this.maria.regs[0x0];
-      $(this.video.canvas).css('background-color', COLORS_WEB[bkcol]);
-    }
-  }
-
-  loadROM(title, data) {
-    if (data.length == 0xc080) data = data.slice(0x80); // strip header
-    this.rom = padBytes(data, romLength, true);
-    this.reset();
-  }
-/*
-  loadBIOS(title, data) {
-    this.bios = padBytes(data, 0x1000);
-    this.reset();
-  }
-*/
-  isRunning() {
-    return this.timer.isRunning();
-  }
-
-  pause() {
-    this.timer.stop();
-    this.audio.stop();
-  }
-
-  resume() {
-    this.timer.start();
-    this.audio.start();
-  }
-
-  reset() {
-    this.cpu.reset();
-    this.tia.reset();
-    this.maria.reset();
-    this.inputs.fill(0x0);
-    this.inputs[SWCHA] = 0xff;
-    this.inputs[SWCHB] = 1+2+8;
-    this.cpu.clockPulse(); // TODO: needed for test to pass?
-  }
-
-  // TODO: don't log if profiler active
-  readAddress(addr : number) {
-    return this.bus.read(addr) | 0;
-  }
-
-  loadState(state) {
-    this.unfixPC(state.c);
-    this.cpu.loadState(state.c);
-    this.fixPC(state.c);
-    this.ram.set(state.b);
-    this.tia.loadState(state.tia);
-    this.maria.loadState(state.maria);
-    this.loadControlsState(state);
-  }
-  saveState() {
-    return {
-      c:this.getCPUState(),
-      b:this.ram.slice(0),
-      tia:this.tia.saveState(),
-      maria:this.maria.saveState(),
-      in:this.inputs.slice(0)
-    };
-  }
-
-  loadControlsState(state) {
-    this.inputs.set(state.in);
-  }
-
-  saveControlsState() {
-    return {
-      in:this.inputs.slice(0)
-    };
-  }
-
-  getCPUState() {
-    return this.fixPC(this.cpu.saveState());
-  }
-
-  getRasterScanline() {
-    return this.scanline;
-  }
-
-  getDebugCategories() {
-    return ['CPU','Stack','TIA','MARIA'];
-  }
-  getDebugInfo(category, state) {
-    switch (category) {
-      case 'TIA': return TIA.stateToLongString(state.tia);
-      case 'MARIA': return MARIA.stateToLongString(state.maria) + "\nScanline: " + this.scanline;
-      default: return super.getDebugInfo(category, state);
-    }
-  }
-}
-
-///
-
-const ATARI_NTSC_RGB = [
-    0x000000,		// 00
-    0x404040,		// 02
-    0x6c6c6c,		// 04
-    0x909090,		// 06
-    0xb0b0b0,		// 08
-    0xc8c8c8,		// 0A
-    0xdcdcdc,		// 0C
-    0xf4f4f4,		// 0E
-    0x004444,		// 10
-    0x106464,		// 12
-    0x248484,		// 14
-    0x34a0a0,		// 16
-    0x40b8b8,		// 18
-    0x50d0d0,		// 1A
-    0x5ce8e8,		// 1C
-    0x68fcfc,		// 1E
-    0x002870,		// 20
-    0x144484,		// 22
-    0x285c98,		// 24
-    0x3c78ac,		// 26
-    0x4c8cbc,		// 28
-    0x5ca0cc,		// 2A
-    0x68b4dc,		// 2C
-    0x78c8ec,		// 2E
-    0x001884,		// 30
-    0x183498,		// 32
-    0x3050ac,		// 34
-    0x4868c0,		// 36
-    0x5c80d0,		// 38
-    0x7094e0,		// 3A
-    0x80a8ec,		// 3C
-    0x94bcfc,		// 3E
-    0x000088,		// 40
-    0x20209c,		// 42
-    0x3c3cb0,		// 44
-    0x5858c0,		// 46
-    0x7070d0,		// 48
-    0x8888e0,		// 4A
-    0xa0a0ec,		// 4C
-    0xb4b4fc,		// 4E
-    0x5c0078,		// 50
-    0x74208c,		// 52
-    0x883ca0,		// 54
-    0x9c58b0,		// 56
-    0xb070c0,		// 58
-    0xc084d0,		// 5A
-    0xd09cdc,		// 5C
-    0xe0b0ec,		// 5E
-    0x780048,		// 60
-    0x902060,		// 62
-    0xa43c78,		// 64
-    0xb8588c,		// 66
-    0xcc70a0,		// 68
-    0xdc84b4,		// 6A
-    0xec9cc4,		// 6C
-    0xfcb0d4,		// 6E
-    0x840014,		// 70
-    0x982030,		// 72
-    0xac3c4c,		// 74
-    0xc05868,		// 76
-    0xd0707c,		// 78
-    0xe08894,		// 7A
-    0xeca0a8,		// 7C
-    0xfcb4bc,		// 7E
-    0x880000,		// 80
-    0x9c201c,		// 82
-    0xb04038,		// 84
-    0xc05c50,		// 86
-    0xd07468,		// 88
-    0xe08c7c,		// 8A
-    0xeca490,		// 8C
-    0xfcb8a4,		// 8E
-    0x7c1800,		// 90
-    0x90381c,		// 92
-    0xa85438,		// 94
-    0xbc7050,		// 96
-    0xcc8868,		// 98
-    0xdc9c7c,		// 9A
-    0xecb490,		// 9C
-    0xfcc8a4,		// 9E
-    0x5c2c00,		// A0
-    0x784c1c,		// A2
-    0x906838,		// A4
-    0xac8450,		// A6
-    0xc09c68,		// A8
-    0xd4b47c,		// AA
-    0xe8cc90,		// AC
-    0xfce0a4,		// AE
-    0x2c3c00,		// B0
-    0x485c1c,		// B2
-    0x647c38,		// B4
-    0x809c50,		// B6
-    0x94b468,		// B8
-    0xacd07c,		// BA
-    0xc0e490,		// BC
-    0xd4fca4,		// BE
-    0x003c00,		// C0
-    0x205c20,		// C2
-    0x407c40,		// C4
-    0x5c9c5c,		// C6
-    0x74b474,		// C8
-    0x8cd08c,		// CA
-    0xa4e4a4,		// CC
-    0xb8fcb8,		// CE
-    0x003814,		// D0
-    0x1c5c34,		// D2
-    0x387c50,		// D4
-    0x50986c,		// D6
-    0x68b484,		// D8
-    0x7ccc9c,		// DA
-    0x90e4b4,		// DC
-    0xa4fcc8,		// DE
-    0x00302c,		// E0
-    0x1c504c,		// E2
-    0x347068,		// E4
-    0x4c8c84,		// E6
-    0x64a89c,		// E8
-    0x78c0b4,		// EA
-    0x88d4cc,		// EC
-    0x9cece0,		// EE
-    0x002844,		// F0
-    0x184864,		// F2
-    0x306884,		// F4
-    0x4484a0,		// F6
-    0x589cb8,		// F8
-    0x6cb4d0,		// FA
-    0x7ccce8,		// FC
-    0x8ce0fc		// FE
-];
-
-var COLORS_RGBA = new Uint32Array(256);
-var COLORS_WEB = [];
-for (var i=0; i<256; i++) {
-  COLORS_RGBA[i] = ATARI_NTSC_RGB[i>>1] | 0xff000000;
-  COLORS_WEB[i] = "#"+hex(rgb2bgr(ATARI_NTSC_RGB[i>>1]),6);
 }
 
 ///
diff --git a/src/ui.ts b/src/ui.ts
index fc4909c1..f152c347 100644
--- a/src/ui.ts
+++ b/src/ui.ts
@@ -7,7 +7,7 @@ import * as bootstrap from "bootstrap";
 import { CodeProject } from "./project";
 import { WorkerResult, WorkerOutput, VerilogOutput, SourceFile, WorkerError, FileData } from "./workertypes";
 import { ProjectWindows } from "./windows";
-import { Platform, Preset, DebugSymbols, DebugEvalCondition } from "./baseplatform";
+import { Platform, Preset, DebugSymbols, DebugEvalCondition, isDebuggable } from "./baseplatform";
 import { PLATFORMS, EmuHalt, Toolbar } from "./emu";
 import * as Views from "./views";
 import { createNewPersistentStore } from "./store";
@@ -89,6 +89,16 @@ function alertInfo(s:string) {
   bootbox.alert(s);
 }
 
+export function loadScript(scriptfn:string) : Promise<Event> {
+  return new Promise( (resolve, reject) => {
+    var script = document.createElement('script');
+    script.onload = resolve;
+    script.onerror = reject;
+    script.src = scriptfn;
+    document.getElementsByTagName('head')[0].appendChild(script);
+  });
+}
+
 function newWorker() : Worker {
   return new Worker("./src/worker/loader.js");
 }
@@ -661,7 +671,7 @@ function _shareEmbedLink(e) {
     return true;
   }
   loadClipboardLibrary();
-  loadScript('lib/liblzg.js', () => {
+  loadScript('lib/liblzg.js').then( () => {
     // TODO: Module is bad var name (conflicts with MAME)
     var lzgrom = compressLZG( window['Module'], Array.from(<Uint8Array>current_output) );
     window['Module'] = null; // so we load it again next time
@@ -686,7 +696,7 @@ function _shareEmbedLink(e) {
 }
 
 function loadClipboardLibrary() {
-  loadScript('lib/clipboard.min.js', () => {
+  loadScript('lib/clipboard.min.js').then( () => {
     var ClipboardJS = exports['ClipboardJS'];
     new ClipboardJS(".btn");
   });
@@ -711,7 +721,7 @@ function _downloadCassetteFile(e) {
     alertError("Cassette export is not supported on this platform.");
     return true;
   }
-  loadScript('lib/c2t.js', () => {
+  loadScript('lib/c2t.js').then( () => {
     var stdout = '';
     var print_fn = function(s) { stdout += s + "\n"; }
     var c2t = window['c2t']({
@@ -828,7 +838,7 @@ function _downloadSourceFile(e) {
 }
 
 function _downloadProjectZipFile(e) {
-  loadScript('lib/jszip.min.js', () => {
+  loadScript('lib/jszip.min.js').then( () => {
     var zip = new JSZip();
     current_project.iterateFiles( (id, data) => {
       if (data) {
@@ -842,7 +852,7 @@ function _downloadProjectZipFile(e) {
 }
 
 function _downloadAllFilesZipFile(e) {
-  loadScript('lib/jszip.min.js', () => {
+  loadScript('lib/jszip.min.js').then( () => {
     var zip = new JSZip();
     store.keys( (err, keys : string[]) => {
       return Promise.all(keys.map( (path) => {
@@ -1010,11 +1020,12 @@ function loadBIOSFromProject() {
 }
 
 function showDebugInfo(state?) {
+  if (!isDebuggable(platform)) return;
   var meminfo = $("#mem_info");
-  var allcats = platform.getDebugCategories && platform.getDebugCategories();
+  var allcats = platform.getDebugCategories();
   if (allcats && !debugCategory)
     debugCategory = allcats[0];
-  var s = state && platform.getDebugInfo && platform.getDebugInfo(debugCategory, state);
+  var s = state && platform.getDebugInfo(debugCategory, state);
   if (s) {
     var hs = lastDebugInfo ? highlightDifferences(lastDebugInfo, s) : s;
     meminfo.show().html(hs);
@@ -1260,7 +1271,7 @@ function setWaitProgress(prog : number) {
 var recordingVideo = false;
 function _recordVideo() {
   if (recordingVideo) return;
- loadScript("gif.js/dist/gif.js", () => {
+ loadScript("gif.js/dist/gif.js").then( () => {
   var canvas = $("#emulator").find("canvas")[0] as HTMLElement;
   if (!canvas) {
     alertError("Could not find canvas element to record video!");
@@ -1815,14 +1826,6 @@ function revealTopBar() {
   setTimeout(() => { $("#controls_dynamic").css('visibility','inherit'); }, 250);
 }
 
-export function loadScript(scriptfn, onload, onerror?) {
-  var script = document.createElement('script');
-  script.onload = onload;
-  script.onerror = onerror;
-  script.src = scriptfn;
-  document.getElementsByTagName('head')[0].appendChild(script);
-}
-
 export function setupSplits() {
   const splitName = 'workspace-split3-' + platform_id;
   var sizes = [0, 50, 50];
@@ -1938,9 +1941,12 @@ export function startUI(loadplatform : boolean) {
 }
 
 function loadAndStartPlatform() {
-  var scriptfn = 'gen/platform/' + platform_id.split(/[.-]/)[0] + '.js';
-  loadScript(scriptfn, () => {
-    console.log("starting platform", platform_id);
+  var platformfn = 'gen/platform/' + platform_id.split(/[.-]/)[0] + '.js'; // required file
+  var machinefn  = platformfn.replace('/platform/', '/machine/'); // optional file
+  loadScript(platformfn).then( () => {
+    return loadScript(machinefn).catch(() => { console.log('skipped',machinefn); }); // optional file skipped
+  }).then( () => {
+    console.log("starting platform", platform_id); // loaded required <platform_id>.js file
     try {
       startPlatform();
       showWelcomeMessage();
@@ -1948,7 +1954,7 @@ function loadAndStartPlatform() {
     } finally {
       revealTopBar();
     }
-  }, () => {
+  }).catch( () => {
     alertError('Platform "' + platform_id + '" not supported.');
   });
 }
diff --git a/test/cli/testplatforms.js b/test/cli/testplatforms.js
index bf213dbe..5f309240 100644
--- a/test/cli/testplatforms.js
+++ b/test/cli/testplatforms.js
@@ -121,6 +121,10 @@ function testPlatform(platid, romname, maxframes, callback) {
     var rom = fs.readFileSync('./test/roms/' + platid + '/' + romname);
     rom = new Uint8Array(rom);
     platform.loadROM("ROM", rom);
+    var state0a = platform.saveState();
+    platform.reset(); // reset again
+    var state0b = platform.saveState();
+    assert.deepEqual(state0a, state0b);
     platform.resume(); // so that recorder works
     platform.setRecorder(rec);
     for (var i=0; i<maxframes; i++) {
@@ -288,5 +292,7 @@ describe('Platform Replay', () => {
         keycallback(Keys.VK_DOWN.c, Keys.VK_DOWN.c, 1);
       }
     });
+    assert.equal(0x1800, platform.saveState().maria.dll);
+    assert.equal(39, platform.readAddress(0x81)); // player y pos
   });
 });