diff --git a/src/platform/nes.ts b/src/platform/nes.ts
index e03cda1d..a8f8409c 100644
--- a/src/platform/nes.ts
+++ b/src/platform/nes.ts
@@ -1,7 +1,7 @@
 
 import { Platform, Base6502Platform, getOpcodeMetadata_6502, getToolForFilename_6502, Preset } from "../common/baseplatform";
 import { PLATFORMS, setKeyboardFromMap, AnimationTimer, RasterVideo, Keys, makeKeycodeMap, KeyFlags, EmuHalt, ControllerPoller } from "../common/emu";
-import { hex, byteArrayToString } from "../common/util";
+import { hex, byteArrayToString, replaceAll } from "../common/util";
 import { CodeAnalyzer_nes } from "../common/analysis";
 import { SampleAudio } from "../common/audio";
 import { ProbeRecorder } from "../common/probe";
@@ -71,16 +71,17 @@ const JSNES_KEYCODE_MAP = makeKeycodeMap([
 
 class JSNESPlatform extends Base6502Platform implements Platform, Probeable {
 
-  mainElement;
+  mainElement : HTMLElement;
   nes;
-  video;
+  video: RasterVideo;
   audio;
-  timer;
+  timer: AnimationTimer;
   poller : ControllerPoller;
   audioFrequency = 44030; //44100
   frameindex = 0;
-  ntvideo;
-  ntlastbuf;
+  ntvideo: RasterVideo;
+  ntlastbuf: Uint32Array;
+  showDebugView = false;
   
   machine = { cpuCyclesPerLine: 114 }; // TODO: hack for width of probe scope
   
@@ -93,21 +94,22 @@ class JSNESPlatform extends Base6502Platform implements Platform, Probeable {
 
   start() {
     this.debugPCDelta = 1;
-    var debugbar = $("<div>").appendTo(this.mainElement);
     this.audio = new SampleAudio(this.audioFrequency);
     this.video = new RasterVideo(this.mainElement,256,224,{overscan:true});
     this.video.create();
     // debugging view
     this.ntvideo = new RasterVideo(this.mainElement,512,480,{overscan:false});
     this.ntvideo.create();
-    $(this.ntvideo.canvas).hide();
+    this.ntvideo.canvas.style.display = 'none';
     this.ntlastbuf = new Uint32Array(0x1000);
     if (Mousetrap.bind) Mousetrap.bind('ctrl+shift+alt+n', () => {
-      $(this.video.canvas).toggle()
-      $(this.ntvideo.canvas).toggle()
+      this.showDebugView = !this.showDebugView;
+      this.video.canvas.style.display = !this.showDebugView ? '' : 'none';
+      this.ntvideo.canvas.style.display = this.showDebugView ? '' : 'none';
     });
     // toggle buttons (TODO)
     /*
+    var debugbar = $("<div>").appendTo(this.mainElement);
     $('<button>').text("Video").appendTo(debugbar).click(() => { $(this.video.canvas).toggle() });
     $('<button>').text("Nametable").appendTo(debugbar).click(() => { $(this.ntvideo.canvas).toggle() });
     */
@@ -162,12 +164,12 @@ class JSNESPlatform extends Base6502Platform implements Platform, Probeable {
 
   advance(novideo : boolean) : number {
     this.nes.frame();
-    return 29780; //TODO
+    return 29780; //TODO: PAL or NTSC?
   }
 
   updateDebugViews() {
    // don't update if view is hidden
-   if (! $(this.ntvideo.canvas).is(":visible"))
+   if (!this.showDebugView)
      return;
    var a = 0;
    var attraddr = 0;
@@ -496,28 +498,29 @@ class JSNESPlatform extends Base6502Platform implements Platform, Probeable {
   getDebugSymbolFile() {
     var sym = this.debugSymbols.addr2symbol;
     var text = "";
-    $.each(sym, function(k, v) {
+    for (let [k, v] of Object.entries(sym)) {
+      let numK = Number(k);
       let symType;
-      if (k < 0x2000) {
-        k = k % 0x800;
+      if (numK < 0x2000) {
+        numK = numK % 0x800;
         symType = "R";
-      } else if (k < 0x6000) symType = "G";
-      else if (k < 0x8000) {
-        k = k - 0x6000;
+      } else if (numK < 0x6000) symType = "G";
+      else if (numK < 0x8000) {
+        numK = numK - 0x6000;
         symType = "S";
-      } else { 
-        k = k - 0x8000;
+      } else {
+        numK = numK - 0x8000;
         symType = "P";
       }
-      let addr = Number(k).toString(16).padStart(4, '0').toUpperCase();
+      let addr = numK.toString(16).padStart(4, '0').toUpperCase();
       // Mesen doesn't allow lables to start with digits
-      if (v[0] >= '0' && v[0] <= '9') {
-      v = "L" + v;
+      if ((v as string)[0] >= '0' && (v as string)[0] <= '9') {
+        v = "L" + v;
       }
       // nor does it allow dots
-      v = (v as any).replaceAll('.', '_');
+      v = replaceAll(v, '.', '_');
       text += `${symType}:${addr}:${v}\n`;
-    });
+    }
     return {
       extension:".mlb", 
       blob: new Blob([text], {type:"text/plain"})
diff --git a/src/tools/8bws.ts b/src/tools/8bws.ts
index 3ddf016a..9351cada 100644
--- a/src/tools/8bws.ts
+++ b/src/tools/8bws.ts
@@ -4,6 +4,8 @@
 
 import * as fs from 'fs';
 import { initialize, compile, compileSourceFile, preload, listTools, listPlatforms, getToolForFilename, PLATFORM_PARAMS, TOOLS, TOOL_PRELOADFS } from './testlib';
+import { isDebuggable } from '../common/baseplatform';
+import { hex } from '../common/util';
 
 interface CLIResult {
   success: boolean;
@@ -150,6 +152,8 @@ function formatGeneric(data: any): void {
   }
 }
 
+var BOOLEAN_FLAGS = new Set(['json', 'info']);
+
 function parseArgs(argv: string[]): { command: string; args: { [key: string]: string }; positional: string[] } {
   var command = argv[2];
   var args: { [key: string]: string } = {};
@@ -158,7 +162,9 @@ function parseArgs(argv: string[]): { command: string; args: { [key: string]: st
   for (var i = 3; i < argv.length; i++) {
     if (argv[i].startsWith('--')) {
       var key = argv[i].substring(2);
-      if (i + 1 < argv.length && !argv[i + 1].startsWith('--')) {
+      if (BOOLEAN_FLAGS.has(key)) {
+        args[key] = 'true';
+      } else if (i + 1 < argv.length && !argv[i + 1].startsWith('--')) {
         args[key] = argv[++i];
       } else {
         args[key] = 'true';
@@ -179,7 +185,7 @@ function usage(): void {
       commands: {
         'compile': 'compile --platform <platform> [--tool <tool>] [--output <file>] <source>',
         'check': 'check --platform <platform> [--tool <tool>] <source>',
-        'run': 'run (--platform <id> | --machine <module:ClassName>) [--frames N] [--output <file.png>] <rom>',
+        'run': 'run (--platform <id> | --machine <module:ClassName>) [--frames N] [--output <file.png>] [--memdump start,end] [--info] <rom>',
         'list-tools': 'list-tools',
         'list-platforms': 'list-platforms',
       }
@@ -301,11 +307,13 @@ async function doRun(args: { [key: string]: string }, positional: string[]): Pro
   var romData = new Uint8Array(fs.readFileSync(romFile));
   var pixels: Uint32Array | null = null;
   var vid: { width: number; height: number } | null = null;
+  var platformRunner: any = null;
+  var machineInstance: any = null;
 
   if (platformId) {
     // Platform mode: load platform module, mock video, run via Platform API
     var { PlatformRunner, loadPlatform } = await import('./runmachine');
-    var platformRunner = new PlatformRunner(await loadPlatform(platformId));
+    platformRunner = new PlatformRunner(await loadPlatform(platformId));
     await platformRunner.start();
     platformRunner.loadROM("ROM", romData);
     for (var i = 0; i < frames; i++) {
@@ -326,7 +334,7 @@ async function doRun(args: { [key: string]: string }, positional: string[]): Pro
     }
     var [modname, clsname] = parts;
     var { MachineRunner, loadMachine } = await import('./runmachine');
-    var machineInstance = await loadMachine(modname, clsname);
+    machineInstance = await loadMachine(modname, clsname);
     var runner = new MachineRunner(machineInstance);
     runner.setup();
     machineInstance.loadROM(romData);
@@ -337,19 +345,6 @@ async function doRun(args: { [key: string]: string }, positional: string[]): Pro
     vid = pixels ? (machineInstance as any).getVideoParams() : null;
   }
 
-  // Encode framebuffer as PNG if video is available
-  var pngData: Uint8Array | null = null;
-  if (pixels && vid) {
-    var { encode } = await import('fast-png');
-    var rgba = new Uint8Array(pixels.buffer);
-    pngData = encode({ width: vid.width, height: vid.height, data: rgba, channels: 4 });
-  }
-
-  // Write PNG to file if requested
-  if (outputFile && pngData) {
-    fs.writeFileSync(outputFile, pngData);
-  }
-
   output({
     success: true,
     command: 'run',
@@ -364,6 +359,90 @@ async function doRun(args: { [key: string]: string }, positional: string[]): Pro
     }
   });
 
+  // --info: print debug info for all categories + disassembly at PC
+  if (args['info'] === 'true') {
+    var plat = platformId ? platformRunner.platform : null;
+    var mach = machine ? machineInstance : null;
+    var debugTarget: any = plat || mach;
+    if (debugTarget && isDebuggable(debugTarget)) {
+      var state = plat?.saveState?.() ?? mach?.saveState?.();
+      if (state) {
+        var categories = debugTarget.getDebugCategories();
+        for (var cat of categories) {
+          var info = debugTarget.getDebugInfo(cat, state);
+          if (info) {
+            process.stderr.write(`${c.bold}${c.magenta}[${cat}]${c.reset}\n`);
+            process.stderr.write(info);
+            if (!info.endsWith('\n')) process.stderr.write('\n');
+          }
+        }
+      }
+    }
+    // Disassembly around current PC
+    if (debugTarget?.getPC && debugTarget?.disassemble && debugTarget?.readAddress) {
+      var pc = debugTarget.getPC();
+      var readFn = (addr: number) => debugTarget.readAddress(addr);
+      process.stderr.write(`${c.bold}${c.magenta}[Disassembly]${c.reset}\n`);
+      var addr = pc;
+      for (var i = 0; i < 16; i++) {
+        var disasm = debugTarget.disassemble(addr, readFn);
+        var prefix = (addr === pc) ? `${c.green}>${c.reset}` : ' ';
+        // show hex bytes
+        var bytesStr = '';
+        for (var b = 0; b < disasm.nbytes; b++) {
+          bytesStr += hex(readFn(addr + b)) + ' ';
+        }
+        process.stderr.write(`${prefix}${c.cyan}$${hex(addr, 4)}${c.reset}  ${c.dim}${bytesStr.padEnd(12)}${c.reset} ${disasm.line}\n`);
+        addr += disasm.nbytes;
+      }
+    }
+  }
+
+  // --memdump start,end: hexdump memory range
+  if (args['memdump']) {
+    var mdparts = args['memdump'].split(',');
+    var start = parseInt(mdparts[0], 16);
+    var end = parseInt(mdparts[1], 16);
+    if (isNaN(start) || isNaN(end) || end < start) {
+      output({ success: false, command: 'run', error: `Invalid --memdump range: ${args['memdump']} (use hex addresses like 0000,00ff)` });
+      process.exit(1);
+    }
+    var plat2 = platformId ? platformRunner.platform : null;
+    var mach2 = machine ? machineInstance : null;
+    var readFn2: ((addr: number) => number) | null = null;
+    if (plat2?.readAddress) readFn2 = (addr) => plat2.readAddress(addr);
+    else if (mach2 && typeof (mach2 as any).read === 'function') readFn2 = (addr) => (mach2 as any).read(addr);
+    if (!readFn2) {
+      output({ success: false, command: 'run', error: 'Platform/machine does not support readAddress' });
+      process.exit(1);
+    }
+    var len = end - start + 1;
+    for (var ofs = 0; ofs < len; ofs += 16) {
+      var line = `${c.cyan}$${hex(start + ofs, 4)}${c.reset}:`;
+      var ascii = '';
+      for (var i = 0; i < 16 && ofs + i < len; i++) {
+        if (i === 8) line += ' ';
+        var byte = readFn2(start + ofs + i);
+        line += ` ${hex(byte)}`;
+        ascii += (byte >= 0x20 && byte < 0x7f) ? String.fromCharCode(byte) : '.';
+      }
+      process.stderr.write(`${line}  ${c.dim}${ascii}${c.reset}\n`);
+    }
+  }
+
+  // Encode framebuffer as PNG if video is available
+  var pngData: Uint8Array | null = null;
+  if (pixels && vid) {
+    var { encode } = await import('fast-png');
+    var rgba = new Uint8Array(pixels.buffer);
+    pngData = encode({ width: vid.width, height: vid.height, data: rgba, channels: 4 });
+  }
+
+  // Write PNG to file if requested
+  if (outputFile && pngData) {
+    fs.writeFileSync(outputFile, pngData);
+  }
+
   // Display image in terminal if connected to a TTY
   if (pngData && process.stdout.isTTY) {
     var { displayImageInTerminal } = await import('./termimage');
@@ -443,6 +522,7 @@ async function main() {
         process.exit(1);
     }
   } catch (e) {
+    console.log(e);
     output({
       success: false,
       command: command,
diff --git a/src/tools/nodemock.ts b/src/tools/nodemock.ts
new file mode 100644
index 00000000..9a158cab
--- /dev/null
+++ b/src/tools/nodemock.ts
@@ -0,0 +1,58 @@
+
+import { SampledAudioSink } from "../common/devices";
+
+import fs from 'fs';
+
+export function mockGlobals() {
+    global.atob = require('atob');
+    global.btoa = require('btoa');
+    (global as any).window = global;
+    (global as any).window.addEventListener = (global as any).window.addEventListener || function () { };
+    (global as any).window.removeEventListener = (global as any).window.removeEventListener || function () { };
+    (global as any).document = (global as any).document || { addEventListener() { }, removeEventListener() { } };
+    try { (global as any).navigator = (global as any).navigator || {}; } catch (e) { }
+}
+
+export class NullAudio implements SampledAudioSink {
+    feedSample(value: number, count: number): void {
+    }
+}
+
+export function mockAudio() {
+    class NullPsgDeviceChannel {
+        setMode() { }
+        setDevice() { }
+        generate() { }
+        setBufferLength() { }
+        setSampleRate() { }
+        getBuffer() { return []; }
+        writeRegister() { }
+        writeRegisterSN() { }
+        writeRegisterAY() { }
+    }
+    class NullMasterChannel {
+        addChannel() { }
+    }
+    global.MasterChannel = NullMasterChannel;
+    global.PsgDeviceChannel = NullPsgDeviceChannel;
+}
+
+export function mockFetch() {
+    global.fetch = async (path, init) => {
+        let bin = fs.readFileSync(path);
+        let blob = new Blob([bin]);
+        return new Response(blob);
+    }
+}
+
+export function mockDOM() {
+  const jsdom = require('jsdom');
+  const { JSDOM } = jsdom;
+  const dom = new JSDOM(`<!DOCTYPE html><div id="emulator"><div id="javatari-screen"></div></div>`);
+  global.window = dom.window;
+  global.document = dom.window.document;
+  //global['$'] = require("jquery/jquery.min.js");
+  dom.window.Audio = null;
+  //global.Image = function () { };
+  return dom;
+}
diff --git a/src/tools/runmachine.ts b/src/tools/runmachine.ts
index 15fba9a9..96ebbab9 100644
--- a/src/tools/runmachine.ts
+++ b/src/tools/runmachine.ts
@@ -1,24 +1,10 @@
 
 import { hasAudio, hasSerialIO, hasVideo, Machine, Platform } from "../common/baseplatform";
-import { SampledAudioSink, SerialIOInterface } from "../common/devices";
+import { SerialIOInterface } from "../common/devices";
 import { PLATFORMS } from "../common/emu";
 import * as emu from "../common/emu";
 import { getRootBasePlatform } from "../common/util";
-
-global.atob = require('atob');
-global.btoa = require('btoa');
-if (typeof window === 'undefined') {
-    (global as any).window = global;
-    (global as any).window.addEventListener = (global as any).window.addEventListener || function () { };
-    (global as any).window.removeEventListener = (global as any).window.removeEventListener || function () { };
-    (global as any).document = (global as any).document || { addEventListener() { }, removeEventListener() { } };
-}
-try { (global as any).navigator = (global as any).navigator || {}; } catch (e) { }
-
-class NullAudio implements SampledAudioSink {
-    feedSample(value: number, count: number): void {
-    }
-}
+import { mockAudio, mockDOM, mockFetch, mockGlobals, NullAudio } from "./nodemock";
 
 // TODO: merge with platform
 class SerialTestHarness implements SerialIOInterface {
@@ -91,6 +77,7 @@ function installHeadlessVideo() {
         this.fillRect = function () { };
         this.fillStyle = '';
         this.putImageData = function () { };
+        this.style = {};
     };
     (emu as any).VectorVideo = function (_mainElement: any, _width: number, _height: number, _options?: any) {
         this.create = function () { this.drawops = 0; };
@@ -115,6 +102,10 @@ export class PlatformRunner {
     private headless: ReturnType<typeof installHeadlessVideo>;
 
     constructor(platform: Platform) {
+        mockGlobals();
+        mockAudio();
+        mockFetch();
+        mockDOM();
         this.platform = platform;
         this.headless = installHeadlessVideo();
     }
diff --git a/test/cli/testplatforms.js b/test/cli/testplatforms.js
index cc51cd83..7b5b9485 100644
--- a/test/cli/testplatforms.js
+++ b/test/cli/testplatforms.js
@@ -83,6 +83,7 @@ emu.RasterVideo = function(mainElement, width, height, options) {
   this.fillRect = function() { }
   this.fillStyle = '';
   this.putImageData = function() { }
+  this.style = {};
 }
 
 emu.VectorVideo = function(mainElement, width, height, options) {
diff --git a/test/roms/gb/cpu_instrs.gb b/test/roms/gb/cpu_instrs.gb
new file mode 100644
index 00000000..7b06221b
Binary files /dev/null and b/test/roms/gb/cpu_instrs.gb differ