Refactor PlatformSpecific functions with time and setTimeout, optimize RewindStep substeps handling, update MTMCClock timing logic, enhance frame processing, and integrate updateJsDisplay for dynamic updates in Main.

.idea/misc.xml

@@ -3,7 +3,7 @@
   <component name="FrameworkDetectionExcludesConfiguration">
     <file type="web" url="file://$PROJECT_DIR$" />
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" project-jdk-name="corretto-21" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="corretto-21" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
   <component name="accountSettings">

.idea/runConfigurations/MTMC_debug.xml

@@ -0,0 +1,7 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="MTMC debug" type="JavascriptDebugType" uri="http://localhost:4001/">
+    <method v="2">
+      <option name="Gradle.BeforeRunTask" enabled="true" tasks="jsBrowserDevelopmentExecutableDistribution" externalProjectPath="$PROJECT_DIR$" vmOptions="" scriptParameters="" />
+    </method>
+  </configuration>
+</component>

.idea/runConfigurations/MainKt.xml

@@ -0,0 +1,10 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="MainKt" type="JetRunConfigurationType" nameIsGenerated="true">
+    <option name="MAIN_CLASS_NAME" value="mtmc.MainKt" />
+    <module name="mtmc-web.jvmMain" />
+    <shortenClasspath name="NONE" />
+    <method v="2">
+      <option name="Make" enabled="true" />
+    </method>
+  </configuration>
+</component>

LICENSE.txt

@@ -0,0 +1,13 @@
+Zero-Clause BSD
+=============
+
+Permission to use, copy, modify, and/or distribute this software for
+any purpose with or without fee is hereby granted.
+
+THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL
+WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE
+FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY
+DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

build.gradle.kts

@@ -1,70 +1,81 @@
 @file:OptIn(ExperimentalDistributionDsl::class)
 
-import org.codehaus.groovy.tools.shell.util.Logger.io
+import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
 import org.jetbrains.kotlin.gradle.targets.js.dsl.ExperimentalDistributionDsl
 
 plugins {
-    kotlin("multiplatform") version "2.1.20"
+  kotlin("multiplatform") version "2.1.20"
 }
 
 group = "nl.astraeus"
 version = "0.1.0-SNAPSHOT"
 
 repositories {
-    mavenCentral()
-    maven {
-        url = uri("https://gitea.astraeus.nl/api/packages/rnentjes/maven")
-    }
-    maven {
-        url = uri("https://gitea.astraeus.nl:8443/api/packages/rnentjes/maven")
-    }
+  mavenCentral()
+  maven {
+    url = uri("https://gitea.astraeus.nl/api/packages/rnentjes/maven")
+  }
+  maven {
+    url = uri("https://gitea.astraeus.nl:8443/api/packages/rnentjes/maven")
+  }
 }
 
 kotlin {
-    jvmToolchain(17)
-    jvm()
-    js {
-        binaries.executable()
-        browser {
-            distribution {
-                outputDirectory.set(File("$projectDir/web/"))
-            }
-        }
+  jvmToolchain(21)
+  jvm {
+    @OptIn(ExperimentalKotlinGradlePluginApi::class)
+    binaries {
+      // Configures a JavaExec task named "runJvm" and a Gradle distribution for the "main" compilation in this target
+      executable {
+        mainClass.set("mtmc.MainKt")
+      }
     }
-    sourceSets {
-        val commonMain by getting {
-            dependencies {
-                api("nl.astraeus:kotlin-simple-logging:1.1.1")
-                api("nl.astraeus:kotlin-css-generator:1.0.10")
-
-                implementation("org.jetbrains.kotlinx:kotlinx-datetime:0.6.0")
-            }
-        }
-        val commonTest by getting
-        val jvmMain by getting {
-            dependencies {
-                implementation("io.undertow:undertow-core:2.3.14.Final")
-                implementation("org.jetbrains.kotlinx:kotlinx-html-jvm:0.11.0")
-
-                implementation("org.xerial:sqlite-jdbc:3.32.3.2")
-                implementation("com.zaxxer:HikariCP:4.0.3")
-                implementation("nl.astraeus:simple-jdbc-stats:1.6.1") {
-                    exclude(group = "org.slf4j", module = "slf4j-api")
-                }
-
-              implementation("io.pebbletemplates:pebble:3.2.3")
-              implementation("com.google.code.gson:gson:2.12.1")
-            }
-        }
-        val jvmTest by getting {
-            dependencies {
-            }
-        }
-        val jsMain by getting {
-            dependencies {
-                implementation("nl.astraeus:kotlin-komponent:1.2.5")
-            }
-        }
-        val jsTest by getting
+  }
+  js {
+    binaries.executable()
+    browser {
+      distribution {
+        outputDirectory.set(File("$projectDir/web/"))
+      }
     }
+  }
+
+  // Add this to enable ExperimentalStdlibApi globally
+  sourceSets.all {
+    languageSettings.optIn("kotlin.ExperimentalStdlibApi")
+  }
+
+  sourceSets {
+    val commonMain by getting {
+      dependencies {
+        api("nl.astraeus:kotlin-simple-logging:1.1.1")
+      }
+    }
+    val commonTest by getting
+    val jvmMain by getting {
+      dependencies {
+        implementation("io.undertow:undertow-core:2.3.14.Final")
+        implementation("org.jetbrains.kotlinx:kotlinx-html-jvm:0.11.0")
+
+        implementation("org.xerial:sqlite-jdbc:3.32.3.2")
+        implementation("com.zaxxer:HikariCP:4.0.3")
+        implementation("nl.astraeus:simple-jdbc-stats:1.6.1") {
+          exclude(group = "org.slf4j", module = "slf4j-api")
+        }
+
+        implementation("io.pebbletemplates:pebble:3.2.3")
+        implementation("com.google.code.gson:gson:2.12.1")
+      }
+    }
+    val jvmTest by getting {
+      dependencies {
+      }
+    }
+    val jsMain by getting {
+      dependencies {
+        implementation("nl.astraeus:kotlin-komponent:1.2.8")
+      }
+    }
+    val jsTest by getting
+  }
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 #Sun Apr 28 09:54:33 CEST 2024
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.11-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

src/commonMain/kotlin/mtmc/asm/ASMElement.kt

@@ -4,9 +4,8 @@ import mtmc.tokenizer.MTMCToken
 
 abstract class ASMElement(
   val labels: List<MTMCToken>,
-  @JvmField var lineNumber: Int
+  var lineNumber: Int
 ) : HasLocation {
-  @JvmField
   var errors: MutableList<ASMError> = ArrayList()
   override var location: Int = 0
   override var sizeInBytes: Int = 0

src/commonMain/kotlin/mtmc/asm/ASMError.kt

@@ -2,10 +2,9 @@ package mtmc.asm
 
 import mtmc.tokenizer.MTMCToken
 
-@JvmRecord
 data class ASMError(
-  @JvmField val token: MTMCToken,
-  @JvmField val error: String
+  val token: MTMCToken,
+  val error: String
 ) {
   fun formattedErrorMessage(): String {
     return "Line " + token.line + ": " + error

src/commonMain/kotlin/mtmc/asm/Assembler.kt

@@ -25,12 +25,16 @@ import mtmc.emulator.Register.Companion.isReadable
 import mtmc.emulator.Register.Companion.isWriteable
 import mtmc.os.SysCall
 import mtmc.os.exec.Executable
+import mtmc.os.fs.File
 import mtmc.tokenizer.MTMCToken
 import mtmc.tokenizer.MTMCTokenizer
-import java.io.File
-import java.nio.charset.StandardCharsets
-import java.util.*
-import java.util.stream.Collectors
+
+fun MutableList<MTMCToken>.poll() = this.removeFirst()
+fun MutableList<MTMCToken>.peekFirst() = if (this.isEmpty()) {
+  null
+} else {
+  this[0]
+}
 
 class Assembler {
   var instructions: MutableList<Instruction> = ArrayList<Instruction>()
@@ -88,7 +92,7 @@ class Assembler {
 
     var location = 0
     var originalLineNumber = 0
-    val currentLocals: MutableMap<String?, LocalInfo?> = TreeMap<String?, LocalInfo?>()
+    val currentLocals: MutableMap<String?, LocalInfo?> = mutableMapOf()
     for (instruction in instructions) {
       val asmLineNumber = instruction.lineNumber
       if (instruction is MetaInstruction) {
@@ -145,10 +149,8 @@ class Assembler {
     val result = assemble(srcName, asm)
     if (!result.errors.isEmpty()) {
       throw RuntimeException(
-        "Errors:\n" + result.errors
-          .stream()
-          .map<String> { e: ASMError? -> " - " + e!!.formattedErrorMessage() }
-          .collect(Collectors.joining("\n")))
+        "Errors:\n" + result.errors.joinToString("\n") { e: ASMError? -> " - " + e!!.formattedErrorMessage() }
+      )
     }
 
     return Executable(
@@ -261,7 +263,10 @@ class Assembler {
       for (labelToken in labelTokens) {
         val labelData = Data(labelTokens, labelToken.line)
         if (hasLabel(labelToken.stringValue)) {
-          labelData.addError(tokens.poll(), "Label already defined: " + labelToken.stringValue)
+          labelData.addError(
+            tokens.removeFirst(),
+            "Label already defined: " + labelToken.stringValue
+          )
         } else {
           this.labels.put(labelToken.labelValue(), labelData)
         }
@@ -274,7 +279,7 @@ class Assembler {
     }
   }
 
-  private fun parseMetaDirective(tokens: LinkedList<MTMCToken>): Boolean {
+  private fun parseMetaDirective(tokens: MutableList<MTMCToken>): Boolean {
     if (tokens.size >= 2 && tokens.get(0).type == MTMCToken.TokenType.AT) {
       tokens.removeFirst()
       val metaInstruction = MetaInstruction(tokens.removeFirst())
@@ -306,26 +311,26 @@ class Assembler {
     return false
   }
 
-  private fun parseModeFlag(tokens: LinkedList<MTMCToken>): ASMMode? {
+  private fun parseModeFlag(tokens: MutableList<MTMCToken>): ASMMode? {
     if (tokens.size >= 2 && tokens.get(0).type == MTMCToken.TokenType.DOT && tokens.get(1).type == MTMCToken.TokenType.IDENTIFIER && tokens.get(
         0
       ).end == tokens.get(1).start && (tokens.get(1).stringValue == "data" ||
           tokens.get(1).stringValue == "text")
     ) {
-      return ASMMode.valueOf(tokens.get(1).stringValue.uppercase(Locale.getDefault()))
+      return ASMMode.valueOf(tokens.get(1).stringValue.uppercase())
     }
     return null
   }
 
-  private fun parseData(tokens: LinkedList<MTMCToken>, labelTokens: MutableList<MTMCToken>) {
+  private fun parseData(tokens: MutableList<MTMCToken>, labelTokens: MutableList<MTMCToken>) {
     lastLabels = mutableListOf()
-    var dataToken = tokens.poll()
+    var dataToken = tokens.removeFirst()
     var dataElt = Data(labelTokens, if (dataToken == null) 0 else dataToken.line)
     if (dataToken != null) {
       if (dataToken.type == MTMCToken.TokenType.STRING) {
-        val stringBytes = dataToken.stringValue.toByteArray(StandardCharsets.US_ASCII)
+        val stringBytes = dataToken.stringValue.encodeToByteArray()
         val nullTerminated = ByteArray(stringBytes.size + 1)
-        System.arraycopy(stringBytes, 0, nullTerminated, 0, stringBytes.size)
+        stringBytes.copyInto(nullTerminated, 0, 0, stringBytes.size)
         nullTerminated[stringBytes.size] = '\u0000'.code.toByte()
         dataElt.setValue(dataToken, nullTerminated)
       } else if (isInteger(dataToken)) {
@@ -338,7 +343,7 @@ class Assembler {
           byteArrayOf((integerValue ushr 8).toByte(), integerValue.toByte())
         )
       } else if (dataToken.type == MTMCToken.TokenType.DOT) {
-        dataToken = tokens.poll()
+        dataToken = tokens.removeFirst()
         dataElt = Data(labelTokens, dataToken.line)
         if (dataToken.stringValue == "int") {
           val intToken = requireIntegerToken(tokens, dataElt, MonTanaMiniComputer.MEMORY_SIZE)
@@ -359,7 +364,7 @@ class Assembler {
           dataElt.addError(dataToken, "only data types are .int, .byte, and .image")
         }
       } else if (dataToken.type == MTMCToken.TokenType.MINUS) {
-        val nextToken = tokens.poll() // get next
+        val nextToken = tokens.removeFirst() // get next
         if (nextToken == null || (nextToken.type != MTMCToken.TokenType.INTEGER && nextToken.type != MTMCToken.TokenType.HEX && nextToken.type != MTMCToken.TokenType.BINARY)) {
           dataElt.addError(dataToken, "Number is too negative")
         } else {
@@ -380,7 +385,7 @@ class Assembler {
 
     for (labelToken in labelTokens) {
       if (hasLabel(labelToken.stringValue)) {
-        dataElt.addError(tokens.poll(), "Label already defined: " + labelToken.stringValue)
+        dataElt.addError(tokens.removeFirst(), "Label already defined: " + labelToken.stringValue)
       } else {
         labels.put(labelToken.labelValue(), dataElt)
       }
@@ -395,7 +400,7 @@ class Assembler {
   ): Graphic {
     val graphic = Graphic(labelTokens, token.line)
     val filename = token.stringValue
-    val file = File(File(this.srcName).getParent(), filename)
+    val file = File(File(this.srcName).parent, filename)
     val index = graphics.size
 
     data.setValue(token, byteArrayOf(((index shr 8) and 0xFF).toByte(), (index and 0xFF).toByte()))
@@ -405,9 +410,16 @@ class Assembler {
     return graphic
   }
 
-  private fun parseInstruction(tokens: LinkedList<MTMCToken>, labelTokens: MutableList<MTMCToken>) {
+  private fun parseInstruction(
+    tokens: MutableList<MTMCToken>,
+    labelTokens: MutableList<MTMCToken>
+  ) {
     var tokens = tokens
-    var instructionToken = tokens.peekFirst()
+    var instructionToken = if (tokens.isEmpty()) {
+      null
+    } else {
+      tokens[0]
+    }
     if (instructionToken == null) return
 
     lastLabels = mutableListOf()
@@ -510,7 +522,7 @@ class Assembler {
       }
 
       // if there is a stack register specified, consume it
-      if (!tokens.isEmpty() && tokens.peekFirst().type == MTMCToken.TokenType.IDENTIFIER) {
+      if (!tokens.isEmpty() && tokens.peekFirst()?.type == MTMCToken.TokenType.IDENTIFIER) {
         val stackReg = requireReadableRegister(tokens, stackInst)
         stackInst.setStackRegister(stackReg)
       }
@@ -550,7 +562,7 @@ class Assembler {
       loadInst.setPointerToken(pointerReg)
 
       // if there is an offset register specified, consume it
-      if (!tokens.isEmpty() && tokens.peekFirst().type == MTMCToken.TokenType.IDENTIFIER) {
+      if (!tokens.isEmpty() && tokens.peekFirst()?.type == MTMCToken.TokenType.IDENTIFIER) {
         val offsetReg = requireReadableRegister(tokens, loadInst)
         loadInst.setOffsetToken(offsetReg)
       }
@@ -598,7 +610,7 @@ class Assembler {
   //===================================================
   // tokenization helper functions
   //===================================================
-  private fun requireSysCall(tokens: LinkedList<MTMCToken>, inst: Instruction): MTMCToken {
+  private fun requireSysCall(tokens: MutableList<MTMCToken>, inst: Instruction): MTMCToken {
     val sysCallType = tokens.poll()
     if (sysCallType == null) {
       inst.addError("Syscall required")
@@ -610,7 +622,7 @@ class Assembler {
     return sysCallType!!
   }
 
-  private fun requireAluOp(tokens: LinkedList<MTMCToken>, inst: Instruction): MTMCToken {
+  private fun requireAluOp(tokens: MutableList<MTMCToken>, inst: Instruction): MTMCToken {
     val sysCallType = tokens.poll()
     if (sysCallType == null) {
       inst.addError("Syscall required")
@@ -623,7 +635,7 @@ class Assembler {
   }
 
   private fun requireWriteableRegister(
-    tokens: LinkedList<MTMCToken>,
+    tokens: MutableList<MTMCToken>,
     instruction: Instruction
   ): MTMCToken {
     val nextToken = tokens.poll()
@@ -638,7 +650,7 @@ class Assembler {
   }
 
   private fun requireReadableRegister(
-    tokens: LinkedList<MTMCToken>,
+    tokens: MutableList<MTMCToken>,
     instruction: Instruction
   ): MTMCToken {
     val nextToken = tokens.poll()
@@ -652,7 +664,7 @@ class Assembler {
     return nextToken!!
   }
 
-  private fun requireALUOp(tokens: LinkedList<MTMCToken>, instruction: Instruction): MTMCToken {
+  private fun requireALUOp(tokens: MutableList<MTMCToken>, instruction: Instruction): MTMCToken {
     val nextToken = tokens.poll()
     if (nextToken == null || nextToken.type != MTMCToken.TokenType.IDENTIFIER || !isALUOp(nextToken.stringValue)) {
       instruction.addError("ALU operation required")
@@ -660,7 +672,7 @@ class Assembler {
     return nextToken!!
   }
 
-  private fun requireString(tokens: LinkedList<MTMCToken>, instruction: ASMElement): MTMCToken {
+  private fun requireString(tokens: MutableList<MTMCToken>, instruction: ASMElement): MTMCToken {
     val nextToken = tokens.poll()
     if (nextToken == null || nextToken.type != MTMCToken.TokenType.STRING) {
       instruction.addError("String required")
@@ -669,7 +681,7 @@ class Assembler {
   }
 
   private fun requireIntegerToken(
-    tokens: LinkedList<MTMCToken>,
+    tokens: MutableList<MTMCToken>,
     inst: ASMElement,
     max: Int
   ): MTMCToken {
@@ -688,7 +700,7 @@ class Assembler {
   }
 
   private fun requireToken(
-    tokens: LinkedList<MTMCToken>,
+    tokens: MutableList<MTMCToken>,
     type: MTMCToken.TokenType,
     inst: ASMElement
   ): MTMCToken? {
@@ -700,7 +712,7 @@ class Assembler {
   }
 
   private fun requireIntegerOrLabelReferenceToken(
-    tokens: LinkedList<MTMCToken>,
+    tokens: MutableList<MTMCToken>,
     inst: LoadStoreInstruction
   ): MTMCToken {
     val token = tokens.poll()
@@ -713,14 +725,14 @@ class Assembler {
   }
 
 
-  private val tokensForLine: LinkedList<MTMCToken>
+  private val tokensForLine: MutableList<MTMCToken>
     get() {
-      val tokens = LinkedList<MTMCToken>()
+      val tokens = mutableListOf<MTMCToken>()
       if (tokenizer!!.more()) {
         val first = tokenizer!!.consume()
         tokens.add(first)
         while (tokenizer!!.more() &&
-          first.line == tokenizer!!.currentToken().line
+          first.line == tokenizer!!.getCurrentToken().line
         ) {
           tokens.add(tokenizer!!.consume())
         }
@@ -742,51 +754,51 @@ class Assembler {
   }
 
   companion object {
-    fun transformSyntheticInstructions(tokens: LinkedList<MTMCToken>): LinkedList<MTMCToken> {
+    fun transformSyntheticInstructions(tokens: MutableList<MTMCToken>): MutableList<MTMCToken> {
       if (!tokens.isEmpty()) {
-        val first = tokens.peekFirst()
+        val first = tokens.first()
         if (first.type == MTMCToken.TokenType.IDENTIFIER) {
           val stringVal = first.stringValue
           if (stringVal.endsWith("i")) {
             val op = stringVal.substring(0, stringVal.length - 1)
             if (isALUOp(op)) {
               val syntheticImmediate = tokens.removeFirst()
-              tokens.addFirst(syntheticImmediate.cloneWithVal(op))
-              tokens.addFirst(syntheticImmediate.cloneWithVal("imm"))
+              tokens.add(0, syntheticImmediate.cloneWithVal(op))
+              tokens.add(0, syntheticImmediate.cloneWithVal("imm"))
             }
           } else if (stringVal.startsWith("s")) {
             val op = stringVal.substring(1, stringVal.length)
             if (isALUOp(op)) {
               val syntheticImmediate = tokens.removeFirst()
-              tokens.addFirst(syntheticImmediate.cloneWithVal(op))
-              tokens.addFirst(syntheticImmediate.cloneWithVal("sop"))
+              tokens.add(0, syntheticImmediate.cloneWithVal(op))
+              tokens.add(0, syntheticImmediate.cloneWithVal("sop"))
             }
           } else if (stringVal == "la") {
             val syntheticImmediate = tokens.removeFirst()
-            tokens.addFirst(syntheticImmediate.cloneWithVal("li"))
+            tokens.add(0, syntheticImmediate.cloneWithVal("li"))
           } else if (stringVal == "ret") {
             val syntheticImmediate = tokens.removeFirst()
-            tokens.addFirst(syntheticImmediate.cloneWithVal("ra"))
-            tokens.addFirst(syntheticImmediate.cloneWithVal("jr"))
+            tokens.add(0, syntheticImmediate.cloneWithVal("ra"))
+            tokens.add(0, syntheticImmediate.cloneWithVal("jr"))
           }
         }
       }
       return tokens
     }
 
-    private fun maybeGetLabels(tokens: LinkedList<MTMCToken>): MutableList<MTMCToken> {
-      val labels = LinkedList<MTMCToken>()
-      while (!tokens.isEmpty() && tokens.getFirst().type == MTMCToken.TokenType.LABEL) {
-        val label = tokens.poll()
+    private fun maybeGetLabels(tokens: MutableList<MTMCToken>): MutableList<MTMCToken> {
+      val labels = mutableListOf<MTMCToken>()
+      while (!tokens.isEmpty() && tokens.first().type == MTMCToken.TokenType.LABEL) {
+        val label = tokens.removeFirst()
         labels.add(label!!)
       }
       return labels
     }
 
-    private fun maybeGetLabelReference(tokens: LinkedList<MTMCToken>): MTMCToken? {
+    private fun maybeGetLabelReference(tokens: MutableList<MTMCToken>): MTMCToken? {
       var label: MTMCToken? = null
-      if (tokens.getFirst().type == MTMCToken.TokenType.IDENTIFIER) {
-        label = tokens.poll()
+      if (tokens.first().type == MTMCToken.TokenType.IDENTIFIER) {
+        label = tokens.removeFirst()
       }
       return label
     }

src/commonMain/kotlin/mtmc/asm/AssemblyResult.kt

@@ -2,13 +2,12 @@ package mtmc.asm
 
 import mtmc.emulator.DebugInfo
 
-@JvmRecord
 data class AssemblyResult(
-  @JvmField val code: ByteArray,
+  val code: ByteArray,
   val data: ByteArray,
   val graphics: Array<ByteArray>,
-  @JvmField val debugInfo: DebugInfo?,
-  @JvmField val errors: MutableList<ASMError>
+  val debugInfo: DebugInfo?,
+  val errors: MutableList<ASMError>
 ) {
   fun printErrors(): String {
     val builder = StringBuilder("Errors:\n")

src/commonMain/kotlin/mtmc/asm/data/Data.kt

@@ -34,4 +34,4 @@ class Data(labels: MutableList<MTMCToken>, lineNumber: Int) : ASMElement(labels,
   override fun addError(err: String) {
     addError(labels.last(), err)
   }
-}
+}

src/commonMain/kotlin/mtmc/asm/graphics/Graphic.kt

@@ -0,0 +1,45 @@
+package mtmc.asm.graphics
+
+import mtmc.asm.ASMElement
+import mtmc.tokenizer.MTMCToken
+
+/**
+ *
+ * @author jbanes
+ */
+class Graphic(labels: MutableList<MTMCToken>, lineNumber: Int) : ASMElement(labels, lineNumber) {
+  private var filename: String? = null
+  var imageData: ByteArray = ByteArray(0)
+
+  fun setImage(filename: String) {
+    /*    try {
+          var image = ImageIO.read(File(filename))
+          val buffer = ByteArrayOutputStream()
+
+          if (image.getWidth() > 1024 || image.getHeight() > 1024) {
+            addError(filename + " is too large. Maximum image size is 1024x1024")
+          }
+
+          image = convertImage(image)
+
+          ImageIO.write(image, "png", buffer)
+
+          this.filename = filename
+          this.imageData = buffer.toByteArray()
+        } catch (e: FileNotFoundException) {
+          e.printStackTrace()
+          addError("$filename not found")
+        } catch (e: IOException) {
+          e.printStackTrace()
+          addError(e.message ?: "error in Graphic") // TODO: Verify these messages are meaningful
+        }*/
+  }
+
+  override fun addError(err: String) {
+    addError(labels.last(), err)
+  }
+
+  override var sizeInBytes: Int
+    get() = 2
+    set(value) {}
+}

src/commonMain/kotlin/mtmc/asm/instructions/ALUInstruction.kt

@@ -5,7 +5,6 @@ import mtmc.emulator.Register.Companion.fromInteger
 import mtmc.emulator.Register.Companion.toInteger
 import mtmc.tokenizer.MTMCToken
 import mtmc.util.BinaryUtils
-import java.util.Locale
 
 class ALUInstruction(
   type: InstructionType,
@@ -38,7 +37,7 @@ class ALUInstruction(
   }
 
   val isBinaryOp: Boolean
-    get() = !ALUOp.valueOf(instructionToken.stringValue.uppercase(Locale.getDefault())).isUnary
+    get() = !ALUOp.valueOf(instructionToken.stringValue.uppercase()).isUnary
 
   override fun genCode(output: ByteArray, assembler: Assembler) {
     val opCode = ALUOp.toInteger(instructionToken.stringValue)
@@ -62,13 +61,12 @@ class ALUInstruction(
   }
 
   companion object {
-    @JvmStatic
     fun disassemble(instruction: Short): String? {
       if (BinaryUtils.getBits(16, 4, instruction).toInt() == 1) {
         val builder = StringBuilder()
         val opCode = BinaryUtils.getBits(12, 4, instruction)
         val op = ALUOp.fromInt(opCode)
-        val aluOp = ALUOp.valueOf(op.uppercase(Locale.getDefault()))
+        val aluOp = ALUOp.valueOf(op.uppercase())
         if (aluOp == ALUOp.IMM) {
           builder.append(op).append(" ")
           builder.append(fromInteger(BinaryUtils.getBits(8, 4, instruction).toInt())).append(" ")

src/commonMain/kotlin/mtmc/asm/instructions/ALUOp.kt

@@ -1,7 +1,5 @@
 package mtmc.asm.instructions
 
-import java.util.*
-
 enum class ALUOp(val opCode: Int, val isUnary: Boolean) {
   ADD(0x0000, false),
   SUB(0x0001, false),
@@ -21,20 +19,17 @@ enum class ALUOp(val opCode: Int, val isUnary: Boolean) {
   IMM(0x000F, true);
 
   companion object {
-    @JvmStatic
     fun toInteger(instruction: String): Int {
-      return valueOf(instruction.uppercase(Locale.getDefault())).opCode
+      return valueOf(instruction.uppercase()).opCode
     }
 
-    @JvmStatic
     fun fromInt(opCode: Short): String {
-      return entries[opCode.toInt()].name.lowercase(Locale.getDefault())
+      return entries[opCode.toInt()].name.lowercase()
     }
 
-    @JvmStatic
     fun isALUOp(op: String): Boolean {
       try {
-        val aluOp = valueOf(op.uppercase(Locale.getDefault()))
+        val aluOp = valueOf(op.uppercase())
         return true
       } catch (e: IllegalArgumentException) {
         return false

src/commonMain/kotlin/mtmc/asm/instructions/Instruction.kt

@@ -7,9 +7,9 @@ import mtmc.emulator.MonTanaMiniComputer.Companion.isDoubleWordInstruction
 import mtmc.tokenizer.MTMCToken
 
 abstract class Instruction(
-  @JvmField val type: InstructionType,
+  val type: InstructionType,
   labels: List<MTMCToken>,
-  @JvmField val instructionToken: MTMCToken
+  val instructionToken: MTMCToken
 ) : ASMElement(labels, instructionToken.line) {
   open fun validateLabel(assembler: Assembler) {
     // default does nothing
@@ -25,7 +25,6 @@ abstract class Instruction(
     get() = type.sizeInBytes
 
   companion object {
-    @JvmStatic
     fun isInstruction(cmd: String): Boolean {
       return InstructionType.fromString(cmd) != null
     }
@@ -58,7 +57,7 @@ abstract class Instruction(
       if (ls != null) {
         return ls
       }
-      val jumpReg = JumpInstruction.disassemble(instruction)
+      val jumpReg = JumpRegisterInstruction.disassemble(instruction)
       if (jumpReg != null) {
         return jumpReg
       }
@@ -66,7 +65,7 @@ abstract class Instruction(
       if (jump != null) {
         return jump
       }
-      return "<unknown>"
+      return ""
     }
   }
 }

src/commonMain/kotlin/mtmc/asm/instructions/InstructionType.kt

@@ -1,9 +1,7 @@
 package mtmc.asm.instructions
 
-import java.util.*
-
-enum class InstructionType @JvmOverloads constructor(
-  @JvmField val instructionClass: InstructionClass?,
+enum class InstructionType constructor(
+  val instructionClass: InstructionClass?,
   val sizeInBytes: Int = 2
 ) {
   SYS(InstructionClass.MISC),
@@ -86,10 +84,9 @@ enum class InstructionType @JvmOverloads constructor(
   }
 
   companion object {
-    @JvmStatic
     fun fromString(string: String): InstructionType? {
       try {
-        return valueOf(string.uppercase(Locale.getDefault()))
+        return valueOf(string.uppercase())
       } catch (e: IllegalArgumentException) {
         return null
       }

src/commonMain/kotlin/mtmc/asm/instructions/JumpRegisterInstruction.kt

@@ -26,10 +26,16 @@ class JumpRegisterInstruction(
 
   companion object {
     fun disassemble(instruction: Short): String? {
-      if (BinaryUtils.getBits(16, 5, instruction).toInt() == 9) {
+      if (BinaryUtils.getBits(16, 4, instruction).toInt() == 9) {
         val reg = BinaryUtils.getBits(4, 4, instruction)
-        val sb = StringBuilder("jr")
-        sb.append(fromInteger(reg.toInt()))
+        if (reg.toInt() == 11) {
+          return "ret"
+        } else {
+          val sb = StringBuilder("jr")
+          sb.append(" ")
+          sb.append(fromInteger(reg.toInt()))
+          return sb.toString()
+        }
       }
       return null
     }

src/commonMain/kotlin/mtmc/emulator/BufferedImage.kt

@@ -0,0 +1,20 @@
+package mtmc.emulator
+
+expect fun createBufferedImage(width: Int, height: Int): BufferedImage
+
+expect fun createCanvasImage(width: Int, height: Int): BufferedImage
+
+expect fun createGLImage(width: Int, height: Int): BufferedImage
+
+interface BufferedImage {
+  val width: Int
+  val height: Int
+
+  fun getRGB(x: Int, y: Int): Int
+  fun setRGB(x: Int, y: Int, intVal: Int)
+}
+
+class Dimension(
+  val width: Int,
+  val height: Int
+)

src/commonMain/kotlin/mtmc/emulator/Color.kt

@@ -0,0 +1,8 @@
+package mtmc.emulator
+
+class Color(
+  val r: Int,
+  val g: Int,
+  val b: Int,
+) {
+}

src/commonMain/kotlin/mtmc/emulator/DebugInfo.kt

@@ -0,0 +1,47 @@
+package mtmc.emulator
+
+import nl.astraeus.logger.getTimestamp
+
+data class DebugInfo(
+  val debugStrings: MutableList<String>,
+  val assemblyFile: String?,
+  val assemblySource: String,
+  val assemblyLineNumbers: IntArray,
+  val originalFile: String,
+  val originalLineNumbers: IntArray,
+  val globals: Array<GlobalInfo>,
+  val locals: Array<Array<LocalInfo?>>
+) {
+  fun handleDebugString(
+    debugIndex: Short,
+    monTanaMiniComputer: MonTanaMiniComputer
+  ) {
+    val debugString = debugStrings!!.get(debugIndex.toInt())
+    /*
+        val compile = Pattern.compile("(\\$[a-zA-Z][a-zA-Z0-9])")
+        val matcher = compile.matcher(debugString)
+        val formattedString = StringBuilder()
+        var start = 0
+        var end: Int
+        while (matcher.find()) {
+          val match = matcher.group().substring(1)
+          try {
+            end = matcher.start()
+            formattedString.append(debugString, start, end)
+            val register = Register.valueOf(match.uppercase())
+            formattedString.append(monTanaMiniComputer.getRegisterValue(register).toInt())
+            start = matcher.end()
+          } catch (e: Exception) {
+            formattedString.append(match)
+          }
+        }
+        formattedString.append(debugString.substring(start))
+        println("DEBUG[" + getTimestamp() + "] : " + formattedString)
+    */
+    println("DEBUG[" + getTimestamp() + "] : " + debugString)
+  }
+
+  data class GlobalInfo(val name: String?, val location: Int, val type: String?)
+
+  data class LocalInfo(val name: String?, val offset: Int, val type: String?)
+}

src/commonMain/kotlin/mtmc/emulator/MTMCClock.kt

@@ -0,0 +1,94 @@
+package mtmc.emulator
+
+import mtmc.emulator.MonTanaMiniComputer.ComputerStatus
+import mtmc.util.currentTimeMillis
+import mtmc.util.requestAnimationFrame
+import mtmc.util.setTimeout
+import mtmc.util.time
+import kotlin.math.max
+import kotlin.math.min
+
+/**
+ *
+ * @author jbanes
+ */
+class MTMCClock(
+  private val computer: MonTanaMiniComputer
+) {
+  var instructions: Long = 0
+  var ips: Long = 0
+  var expected: Long = 0
+  var virtual: Long = 0
+
+  var startTime = currentTimeMillis()
+  var lastFrame = 0.0
+
+  var speed: Long = 0
+
+  var instructionsToRun = 0.0
+  var frame = 0
+
+  fun run() {
+    requestAnimationFrame { handleFrame() }
+  }
+
+  fun handleFrame() {
+    // figure out how many instructions to execute this 'time' duration
+    // maximize time so we don't hang if the emulator is too slow
+    val time = time()
+    if (lastFrame == 0.0) {
+      lastFrame = time
+      requestAnimationFrame { handleFrame() }
+      return
+    }
+    val delta = time - lastFrame
+    lastFrame = time
+
+    val timeToProcess = min(delta, 16.0)
+
+    // assume 1Hz = 1 instruction/second
+    if (computer.getStatus() == ComputerStatus.EXECUTING) {
+      speed = max(computer.speed, 0).toLong()
+      if (speed == 0L) {
+        speed = 1L
+      }
+
+      instructionsToRun += timeToProcess * speed / 1000.0
+      val pulse: Long = instructionsToRun.toLong() + 1
+      instructionsToRun -= pulse
+
+      val start = time()
+      val ir = computer.pulse(pulse)
+      instructions += ir
+      val duration = (time() - start)
+      val actual = ir / (delta / 1000.0)
+      if (frame % 100 == 0) {
+        println("Instructions ran: $ir (delta = ${delta.toFloat()}, timeToProcess = ${timeToProcess.toFloat()}, speed = $speed (actual=${actual.toLong()}), duration = $duration)")
+      }
+
+      virtual += instructions
+      ips = (instructions / timeToProcess).toLong()
+      frame++
+
+      if (duration > timeToProcess) {
+        setTimeout({ handleFrame() })
+      } else {
+        requestAnimationFrame { handleFrame() }
+      }
+    }
+
+    //println("Executed " + instructions + " instructions at a rate of " + ips + " ips (speed = " + speed + ")")
+  }
+
+  fun step() {
+    computer.fetchAndExecute()
+    computer.fetchCurrentInstruction()
+    computer.notifyOfStepExecution()
+  }
+
+  fun back() {
+    computer.rewind()
+    computer.fetchCurrentInstruction()
+    computer.notifyOfStepExecution()
+  }
+}

src/commonMain/kotlin/mtmc/emulator/MTMCConsole.kt

@@ -1,16 +1,16 @@
 package mtmc.emulator
 
+import mtmc.os.fs.Console
 import mtmc.os.shell.Shell
 import mtmc.tokenizer.MTMCScanner
 import mtmc.tokenizer.MTMCToken
-import java.io.Console
 
 class MTMCConsole(private val computer: MonTanaMiniComputer) {
-  var mode: Mode = Mode.NON_INTERACTIVE
+  var mode: Mode = Mode.INTERACTIVE
   var sysConsole: Console? = null
 
   // non-interactive data
-  private val output = StringBuffer()
+  private var output = StringBuilder()
   private var shortValueSet = false
   private var shortValue: Short = 0
   private var stringValue: String? = null
@@ -18,12 +18,7 @@ class MTMCConsole(private val computer: MonTanaMiniComputer) {
   // TODO invert so shell is driving and console is just IO
   fun start() {
     mode = Mode.INTERACTIVE
-    sysConsole = System.console()
     Shell.printShellWelcome(computer)
-    while (true) {
-      val cmd = sysConsole!!.readLine("mtmc > ")
-      computer.oS.processCommand(cmd)
-    }
   }
 
   fun println(x: String) {
@@ -48,7 +43,7 @@ class MTMCConsole(private val computer: MonTanaMiniComputer) {
     if (mode == Mode.INTERACTIVE) {
       val tokens = MTMCScanner(sysConsole!!.readLine(), "#").tokenize()
       val token = tokens.first()
-      assert(token.type === MTMCToken.TokenType.CHAR)
+      check(token.type === MTMCToken.TokenType.CHAR)
       return token.charValue()
     } else {
       this.shortValueSet = false
@@ -88,7 +83,9 @@ class MTMCConsole(private val computer: MonTanaMiniComputer) {
     val text = if (index >= 0) output.substring(0, index + 1) else ""
 
     if (index >= 0) {
-      output.delete(0, index + 1)
+      val updated = StringBuilder()
+      updated.append(output.removeRange(0, index + 1))
+      output = updated
     }
 
     return text
@@ -121,7 +118,7 @@ class MTMCConsole(private val computer: MonTanaMiniComputer) {
   }
 
   fun resetOutput() {
-    output.delete(0, output.length)
+    output.clear()
   }
 
   enum class Mode {

src/commonMain/kotlin/mtmc/emulator/MTMCIO.kt

@@ -1,7 +1,5 @@
 package mtmc.emulator
 
-import java.util.*
-
 class MTMCIO {
   var value: Int = 0
 
@@ -17,12 +15,12 @@ class MTMCIO {
   }
 
   fun keyPressed(key: String) {
-    val button = Buttons.valueOf(key.uppercase(Locale.getDefault()))
+    val button = Buttons.valueOf(key.uppercase())
     value = value or button.mask
   }
 
   fun keyReleased(key: String) {
-    val button = Buttons.valueOf(key.uppercase(Locale.getDefault()))
+    val button = Buttons.valueOf(key.uppercase())
     value = value and button.mask.inv()
   }
 }

src/commonMain/kotlin/mtmc/emulator/MonTanaMiniComputer.kt

@@ -4,19 +4,7 @@ import mtmc.asm.instructions.Instruction
 import mtmc.os.MTOS
 import mtmc.os.fs.FileSystem
 import mtmc.util.BinaryUtils.getBits
-import java.lang.Byte
-import java.util.*
-import java.util.function.Consumer
-import java.util.stream.IntStream
-import kotlin.Array
-import kotlin.Boolean
-import kotlin.ByteArray
-import kotlin.Int
-import kotlin.IntArray
-import kotlin.Long
-import kotlin.Short
-import kotlin.ShortArray
-import kotlin.String
+import mtmc.util.Runnable
 import kotlin.experimental.and
 import kotlin.experimental.inv
 import kotlin.experimental.or
@@ -30,7 +18,7 @@ class MonTanaMiniComputer {
   var memory: ByteArray = ByteArray(MEMORY_SIZE)
   var breakpoints: ByteArray = ByteArray(MEMORY_SIZE)
   private var status: ComputerStatus? = ComputerStatus.READY
-  var speed: Int = 1000000
+  var speed: Int = 1
     set(speed) {
       field = speed
       this.notifyOfExecutionUpdate()
@@ -43,10 +31,12 @@ class MonTanaMiniComputer {
   var display: MTMCDisplay = MTMCDisplay(this)
   var clock: MTMCClock = MTMCClock(this)
   var fileSystem: FileSystem = FileSystem(this)
-  var rewindSteps: LinkedList<RewindStep>? = LinkedList<RewindStep>()
+
+  var rewindSteps = Array(MAX_REWIND_STEPS) { RewindStep() }
+  var rewindIndex = -1
 
   // listeners
-  private val observers: MutableList<MTMCObserver> = ArrayList<MTMCObserver>()
+  private val observers = mutableListOf<MTMCObserver>()
   var debugInfo: DebugInfo? = null
   private var currentRewindStep: RewindStep? = null
 
@@ -58,32 +48,33 @@ class MonTanaMiniComputer {
     registerFile = ShortArray(Register.entries.size)
     memory = ByteArray(MEMORY_SIZE)
     breakpoints = ByteArray(MEMORY_SIZE)
-    rewindSteps = null
     setRegisterValue(
       Register.SP,
       MEMORY_SIZE.toShort().toInt()
     ) // default the stack pointer to the top of memory
-    rewindSteps = LinkedList<RewindStep>()
-    observers!!.forEach(Consumer { obj: MTMCObserver? -> obj!!.computerReset() })
+    rewindIndex = -1
+    observers.forEach { obj ->
+      obj.computerReset()
+    }
   }
 
-  fun load(code: ByteArray, data: ByteArray, debugInfo: DebugInfo?) {
-    load(code, data, Array(0) { ByteArray(0) }, debugInfo)
-  }
-
-  fun load(code: ByteArray, data: ByteArray, graphics: Array<ByteArray>, debugInfo: DebugInfo?) {
+  fun load(
+    code: ByteArray,
+    data: ByteArray,
+    graphics: Array<ByteArray> = arrayOf(),
+    debugInfo: DebugInfo? = null
+  ) {
     this.debugInfo = debugInfo
 
     // reset memory
     initMemory()
 
-
     val codeBoundary = code.size
-    System.arraycopy(code, 0, memory, 0, codeBoundary)
+    code.copyInto(memory, 0, 0, codeBoundary)
     setRegisterValue(Register.CB, codeBoundary - 1)
 
     val dataBoundary = codeBoundary + data.size
-    System.arraycopy(data, 0, memory, codeBoundary, data.size)
+    data.copyInto(memory, codeBoundary, 0, data.size)
     setRegisterValue(Register.DB, dataBoundary - 1)
 
 
@@ -142,8 +133,9 @@ class MonTanaMiniComputer {
   }
 
   fun fetchAndExecute() {
-    currentRewindStep = RewindStep()
-    rewindSteps!!.push(currentRewindStep)
+    rewindIndex = (rewindIndex + 1) % rewindSteps.size
+    rewindSteps[rewindIndex].index = 0
+
     fetchCurrentInstruction()
     val instruction = getRegisterValue(Register.IR)
     if (isDoubleWordInstruction(instruction)) {
@@ -158,7 +150,7 @@ class MonTanaMiniComputer {
   }
 
   fun execInstruction(instruction: Short) {
-    observers!!.forEach(Consumer { o: MTMCObserver? -> o!!.beforeExecution(instruction) })
+    observers!!.forEach({ o: MTMCObserver? -> o!!.beforeExecution(instruction) })
     val instructionType: Short = getBits(16, 4, instruction)
     if (instructionType.toInt() == 0x0000) { // MISC
       val topNibble: Int = getBits(12, 4, instruction).toInt()
@@ -710,7 +702,9 @@ class MonTanaMiniComputer {
     } else {
       badInstruction(instruction)
     }
-    observers.forEach(Consumer { o: MTMCObserver? -> o!!.afterExecution(instruction) })
+    observers.forEach { o: MTMCObserver? ->
+      o!!.afterExecution(instruction)
+    }
   }
 
   val isFlagTestBitSet: Boolean
@@ -733,7 +727,11 @@ class MonTanaMiniComputer {
   private fun badInstruction(instruction: Short) {
     setStatus(ComputerStatus.PERMANENT_ERROR)
     // TODO implement flags
-    console.println("BAD INSTRUCTION: 0x" + Integer.toHexString(instruction.toInt() and 0xFFFF))
+    console.println(
+      "BAD INSTRUCTION: 0x" + (instruction.toHexString()) + " at PC " + getRegisterValue(
+        Register.PC
+      )
+    )
   }
 
   fun fetchCurrentInstruction() {
@@ -746,14 +744,16 @@ class MonTanaMiniComputer {
     } else {
       setRegisterValue(Register.DR, 0)
     }
-    observers!!.forEach(Consumer { o: MTMCObserver? -> o!!.instructionFetched(instruction) })
+    observers.forEach { o: MTMCObserver? ->
+      o!!.instructionFetched(instruction)
+    }
   }
 
   fun fetchWordFromMemory(address: Int): Short {
     val upperByte = fetchByteFromMemory(address).toShort()
     val lowerByte = fetchByteFromMemory(address + 1)
     var value = (upperByte.toInt() shl 8).toShort()
-    val i = value.toInt() or Byte.toUnsignedInt(lowerByte)
+    val i = value.toInt() + (lowerByte.toInt() and 255)
     value = i.toShort()
     return value
   }
@@ -762,9 +762,8 @@ class MonTanaMiniComputer {
     if (address < 0 || address >= memory.size) {
       setStatus(ComputerStatus.PERMANENT_ERROR)
       console.println(
-        "BAD MEMORY LOCATION ON READ: " + address + " (0x" + Integer.toHexString(
-          address and 0xFFFF
-        ) + ")"
+        "BAD MEMORY LOCATION ON READ: $address (0x" +
+            (address and 0xFFFF).toHexString() + ")"
       )
       return 0
     } else {
@@ -782,24 +781,22 @@ class MonTanaMiniComputer {
     if (address < 0 || address >= memory.size) {
       setStatus(ComputerStatus.PERMANENT_ERROR)
       console.println(
-        "BAD MEMORY LOCATION ON WRITE: " + address + " (0x" + Integer.toHexString(
-          address and 0xFFFF
-        ) + ")"
+        "BAD MEMORY LOCATION ON WRITE: " + address + " (0x" +
+            (address and 0xFFFF).toHexString() + ")"
       )
       return
     }
     val currentValue = memory[address]
-    addRewindStep(Runnable { memory[address] = currentValue })
+    addRewindStep { memory[address] = currentValue }
     memory[address] = value
-    observers!!.forEach(Consumer { o: MTMCObserver? -> o!!.memoryUpdated(address, value) })
+    observers.forEach { o: MTMCObserver? ->
+      o!!.memoryUpdated(address, value)
+    }
   }
 
   private fun addRewindStep(runnable: Runnable?) {
-    if (currentRewindStep != null && rewindSteps != null) {
+    if (currentRewindStep != null) {
       currentRewindStep!!.addSubStep(runnable)
-      if (rewindSteps!!.size > MAX_REWIND_STEPS) {
-        rewindSteps!!.removeLast()
-      }
     }
   }
 
@@ -812,11 +809,13 @@ class MonTanaMiniComputer {
       // TODO mark as overflow
     }
     val currentValue = registerFile[register]
-    addRewindStep(Runnable {
+    addRewindStep {
       registerFile[register] = currentValue
-    })
+    }
     registerFile[register] = value.toShort()
-    observers!!.forEach(Consumer { o: MTMCObserver? -> o!!.registerUpdated(register, value) })
+    observers.forEach { o: MTMCObserver? ->
+      o!!.registerUpdated(register, value)
+    }
   }
 
   fun getRegisterValue(register: Register): Short {
@@ -845,12 +844,14 @@ class MonTanaMiniComputer {
     breakpoints[address] = (if (active) 1.toByte() else 0.toByte())
   }
 
-  private fun start() {
+  fun start() {
     console.start() // start the interactive console
   }
 
   fun getBytesFromMemory(address: Int, length: Int): ByteArray {
-    return Arrays.copyOfRange(memory, address, address + length)
+    val result = ByteArray(length)
+    memory.copyInto(result, 0, address, address + length)
+    return result
   }
 
   val oS: MTOS
@@ -858,18 +859,15 @@ class MonTanaMiniComputer {
 
   val memoryAddresses: Iterable<Int?>
     get() = Iterable {
-      IntStream.range(
-        0,
-        MEMORY_SIZE
-      ).iterator()
+      (0..MEMORY_SIZE).iterator()
     }
 
   fun addObserver(observer: MTMCObserver?) {
-    observers!!.add(observer!!)
+    observers.add(observer!!)
   }
 
   fun removeObserver(observer: MTMCObserver?) {
-    observers!!.remove(observer!!)
+    observers.remove(observer!!)
   }
 
   fun pause() {
@@ -936,7 +934,7 @@ class MonTanaMiniComputer {
   fun setArg(arg: String) {
     if (!arg.isEmpty()) {
       val start = getRegisterValue(Register.BP)
-      val bytes = arg.toByteArray()
+      val bytes = arg.encodeToByteArray()
       writeStringToMemory(start.toInt(), bytes)
       setRegisterValue(Register.A0, start.toInt())
       setRegisterValue(Register.BP, start + bytes.size + 1)
@@ -953,12 +951,15 @@ class MonTanaMiniComputer {
   }
 
   fun rewind() {
-    val latestRewindStep = rewindSteps!!.pop()
-    latestRewindStep.rewind()
+    if (rewindIndex >= 0) {
+      val latestRewindStep = rewindSteps[rewindIndex]
+      rewindIndex--
+      latestRewindStep?.rewind()
+    }
   }
 
   val isBackAvailable: Boolean
-    get() = !rewindSteps!!.isEmpty()
+    get() = rewindIndex >= 0
 
   enum class ComputerStatus {
     READY,
@@ -1014,17 +1015,8 @@ class MonTanaMiniComputer {
         return true
       }
       val isMcp = getBits(16, 8, instruction) == 5.toShort()
-      if (isMcp) {
-        return true
-      }
-      return false
-    }
 
-    @JvmStatic
-    fun main(args: Array<String>) {
-      val computer = MonTanaMiniComputer()
-      computer.speed = 1 // default to 1hz
-      computer.start()
+      return isMcp
     }
   }
 }

src/commonMain/kotlin/mtmc/emulator/Register.kt

@@ -73,4 +73,4 @@ enum class Register {
             }
         }
     }
-}
+}

src/commonMain/kotlin/mtmc/emulator/RewindStep.kt

@@ -0,0 +1,18 @@
+package mtmc.emulator
+
+import mtmc.util.Runnable
+
+class RewindStep {
+  var subSteps: Array<Runnable> = Array(10) { {} }
+  var index = 0
+
+  fun rewind() {
+    subSteps.reversed().forEach({ obj: Runnable? -> obj!!.invoke() })
+  }
+
+  fun addSubStep(subStep: Runnable?) {
+    if (subStep != null && index < subSteps.size) {
+      subSteps[index++] = subStep
+    }
+  }
+}

src/commonMain/kotlin/mtmc/os/MTOS.kt

@@ -3,18 +3,17 @@ package mtmc.os
 import mtmc.emulator.MonTanaMiniComputer
 import mtmc.emulator.Register
 import mtmc.os.SysCall.Companion.getValue
+import mtmc.os.fs.File
+import mtmc.os.fs.Files
 import mtmc.os.shell.Shell
-import java.io.File
-import java.io.IOException
-import java.nio.file.Files
-import java.util.*
+import mtmc.util.currentTimeMillis
 import kotlin.math.max
 import kotlin.math.min
-import kotlin.text.Charsets.US_ASCII
+import kotlin.random.Random
 
 class MTOS(private val computer: MonTanaMiniComputer) {
-  private var timer: Long = 0
-  var random: Random = Random()
+  private var timer: Double = 0.0
+  var random: Random = Random.Default
 
   // Editor support
   var currentFile: String? = null
@@ -52,59 +51,59 @@ class MTOS(private val computer: MonTanaMiniComputer) {
   fun handleSysCall(syscallNumber: Short) {
     if (syscallNumber == getValue("exit").toShort()) {
       computer.setStatus(MonTanaMiniComputer.ComputerStatus.FINISHED)
-    } else if (syscallNumber == getValue("rint").toShort()) {
-      // rint
-      if (!computer.console.hasShortValue()) {
-        computer.notifyOfRequestInteger()
-      }
-      while (!computer.console.hasShortValue() && computer.getStatus() == MonTanaMiniComputer.ComputerStatus.EXECUTING) {
-        try {
-          Thread.sleep(10)
-        } catch (e: InterruptedException) {
-        }
-      }
-      val `val` = computer.console.readInt()
-      computer.setRegisterValue(Register.RV, `val`.toInt())
+//    } else if (syscallNumber == getValue("rint").toShort()) {
+//      // rint
+//      if (!computer.console.hasShortValue()) {
+//        computer.notifyOfRequestInteger()
+//      }
+//      while (!computer.console.hasShortValue() && computer.getStatus() == MonTanaMiniComputer.ComputerStatus.EXECUTING) {
+//        try {
+//          Thread.sleep(10)
+//        } catch (e: InterruptedException) {
+//        }
+//      }
+//      val `val` = computer.console.readInt()
+//      computer.setRegisterValue(Register.RV, `val`.toInt())
     } else if (syscallNumber == getValue("wint").toShort()) {
       // wint
       val value = computer.getRegisterValue(Register.A0)
       computer.console.writeInt(value)
-    } else if (syscallNumber == getValue("rchr").toShort()) {
-      if (!computer.console.hasShortValue()) {
-        computer.notifyOfRequestCharacter()
-      }
-      while (!computer.console.hasShortValue() && computer.getStatus() == MonTanaMiniComputer.ComputerStatus.EXECUTING) {
-        try {
-          Thread.sleep(10)
-        } catch (e: InterruptedException) {
-        }
-      }
-      val `val` = computer.console.readChar()
-      computer.setRegisterValue(Register.RV, `val`.code)
+//    } else if (syscallNumber == getValue("rchr").toShort()) {
+//      if (!computer.console.hasShortValue()) {
+//        computer.notifyOfRequestCharacter()
+//      }
+//      while (!computer.console.hasShortValue() && computer.getStatus() == MonTanaMiniComputer.ComputerStatus.EXECUTING) {
+//        try {
+//          Thread.sleep(10)
+//        } catch (e: InterruptedException) {
+//        }
+//      }
+//      val `val` = computer.console.readChar()
+//      computer.setRegisterValue(Register.RV, `val`.code)
     } else if (syscallNumber == getValue("wchr").toShort()) {
       val value = computer.getRegisterValue(Register.A0)
       computer.console.print("" + Char(value.toUShort()))
-    } else if (syscallNumber == getValue("rstr").toShort()) {
-      // rstr
-      val pointer = computer.getRegisterValue(Register.A0)
-      val maxLen = computer.getRegisterValue(Register.A1)
-      if (!computer.console.hasReadString()) {
-        computer.notifyOfRequestString()
-      }
-      while (!computer.console.hasReadString() && computer.getStatus() == MonTanaMiniComputer.ComputerStatus.EXECUTING) {
-        try {
-          Thread.sleep(10)
-        } catch (e: InterruptedException) {
-        }
-      }
-      val string = computer.console.readString()
-      val bytes = string!!.toByteArray(US_ASCII)
-      val bytesToRead = min(bytes.size, maxLen.toInt())
-      for (i in 0..<bytesToRead) {
-        val aByte = bytes[i]
-        computer.writeByteToMemory(pointer + i, aByte)
-      }
-      computer.setRegisterValue(Register.RV, bytesToRead)
+//    } else if (syscallNumber == getValue("rstr").toShort()) {
+//      // rstr
+//      val pointer = computer.getRegisterValue(Register.A0)
+//      val maxLen = computer.getRegisterValue(Register.A1)
+//      if (!computer.console.hasReadString()) {
+//        computer.notifyOfRequestString()
+//      }
+//      while (!computer.console.hasReadString() && computer.getStatus() == MonTanaMiniComputer.ComputerStatus.EXECUTING) {
+//        try {
+//          Thread.sleep(10)
+//        } catch (e: InterruptedException) {
+//        }
+//      }
+//      val string = computer.console.readString()
+//      val bytes = string!!.encodeToByteArray()
+//      val bytesToRead = min(bytes.size, maxLen.toInt())
+//      for (i in 0..<bytesToRead) {
+//        val aByte = bytes[i]
+//        computer.writeByteToMemory(pointer + i, aByte)
+//      }
+//      computer.setRegisterValue(Register.RV, bytesToRead)
     } else if (syscallNumber == getValue("wstr").toShort()) {
       // wstr
       val pointer = computer.getRegisterValue(Register.A0)
@@ -172,14 +171,14 @@ class MTOS(private val computer: MonTanaMiniComputer) {
       }
 
       computer.setRegisterValue(Register.RV, random.nextInt(low.toInt(), high + 1))
-    } else if (syscallNumber == getValue("sleep").toShort()) {
-      // sleep
-      val millis = computer.getRegisterValue(Register.A0)
-      try {
-        if (millis > 0) Thread.sleep(millis.toLong())
-      } catch (e: InterruptedException) {
-        throw RuntimeException(e)
-      }
+//    } else if (syscallNumber == getValue("sleep").toShort()) {
+//      // sleep
+//      val millis = computer.getRegisterValue(Register.A0)
+//      try {
+//        if (millis > 0) Thread.sleep(millis.toLong())
+//      } catch (e: InterruptedException) {
+//        throw RuntimeException(e)
+//      }
     } else if (syscallNumber == getValue("fbreset").toShort()) {
       // fbreset
       computer.display.reset()
@@ -241,9 +240,40 @@ class MTOS(private val computer: MonTanaMiniComputer) {
       try {
         // special handling for game-of-life cell files
         if ("cells" == fileType) {
-          val str = Files.readString(file.toPath())
-          val lines = Arrays
-            .stream<String>(str.split("\n".toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray())
+          //val str = Files.readString(file.toPath())
+          val str = """
+            ! galaxy
+            ! Kok's galaxy - a whirling oscillator
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+            ...............OOOOOO.OO.....
+            ...............OOOOOO.OO
+            ......................OO
+            ...............OO.....OO
+            ...............OO.....OO
+            ...............OO.....OO
+            ...............OO.......
+            ...............OO.OOOOOO
+            ...............OO.OOOOOO.......................................
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+            .......................................
+          """.trimIndent()
+          val lines: List<String> =
+            str.split("\n".toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray()
             .filter { s: String? -> !s!!.startsWith("!") }
             .toList()
 
@@ -251,7 +281,7 @@ class MTOS(private val computer: MonTanaMiniComputer) {
           val cappedLines = min(linesTotal, maxSize2.toInt())
 
           for (lineNum in 0..<cappedLines) {
-            val line = lines.get(lineNum)
+            val line: String = lines.get(lineNum)
             for (colNum in 0..<maxSize1) {
               val offset = lineNum * maxSize1 + colNum
               val byteOffset = offset / 8
@@ -275,7 +305,7 @@ class MTOS(private val computer: MonTanaMiniComputer) {
           }
         }
         computer.setRegisterValue(Register.RV, 0)
-      } catch (e: IOException) {
+      } catch (e: Exception) {
         computer.setRegisterValue(Register.RV, -1)
         e.printStackTrace() // debugging
       }
@@ -290,7 +320,6 @@ class MTOS(private val computer: MonTanaMiniComputer) {
         computer.writeByteToMemory(destination + i, aByte)
       }
 
-
       //TODO: Should this return the length with or without the null terminator?
       computer.writeByteToMemory(destination + maxSize - 1, 0.toByte())
       computer.setRegisterValue(Register.RV, maxSize - 1)
@@ -300,18 +329,18 @@ class MTOS(private val computer: MonTanaMiniComputer) {
 
       if (computer.fileSystem.exists(dir)) {
         computer.setRegisterValue(Register.RV, 0)
-        computer.fileSystem.setCWD(dir)
+        computer.fileSystem.cWD = dir
       } else {
         computer.setRegisterValue(Register.RV, 1)
       }
     } else if (syscallNumber == getValue("timer").toShort()) {
       val value = computer.getRegisterValue(Register.A0)
 
-      if (value > 0) this.timer = System.currentTimeMillis() + value
+      if (value > 0) this.timer = currentTimeMillis() + value
 
       computer.setRegisterValue(
         Register.RV,
-        max(0, this.timer - System.currentTimeMillis()).toInt()
+        max(0.0, this.timer - currentTimeMillis()).toInt()
       )
     } else if (syscallNumber == getValue("drawimg").toShort()) {
       val image = computer.getRegisterValue(Register.A0)
@@ -401,10 +430,13 @@ class MTOS(private val computer: MonTanaMiniComputer) {
         }
 
         val file = list[offset.toInt()]
-        val name = file.getName()
+        val name = file.name
         val size = min(maxSizeOut - 1, name.length)
 
-        computer.writeWordToMemory(destination.toInt(), if (file.isDirectory()) 1 else 0)
+        computer.writeWordToMemory(
+          destination.toInt(),
+          if (file.directory) 1 else 0
+        )
 
         for (i in 0..<size) {
           val aByte = name.get(i).code.toByte()
@@ -433,9 +465,9 @@ class MTOS(private val computer: MonTanaMiniComputer) {
       length++
     }
     try {
-      val outputString = String(computer.memory, pointer.toInt(), length.toInt(), US_ASCII)
+      val outputString = computer.memory.decodeToString(pointer.toInt(), pointer.toInt() + length)
       return outputString
-    } catch (ignored: StringIndexOutOfBoundsException) {
+    } catch (ignored: IndexOutOfBoundsException) {
       computer.setStatus(MonTanaMiniComputer.ComputerStatus.PERMANENT_ERROR)
       return ""
     }
@@ -447,9 +479,12 @@ class MTOS(private val computer: MonTanaMiniComputer) {
     }
   }
 
-  fun loadFile(path: String?): File {
-    val fs = computer.fileSystem
-    val file = fs.getRealPath(path).toFile()
-    return file
-  }
+  fun loadFile(path: String?): File = File(path ?: "<empty>")
+  /*
+    {
+      val fs = computer.fileSystem
+      val file = fs.getRealPath(path).toFile()
+      return file
+    }
+  */
 }

src/commonMain/kotlin/mtmc/os/SysCall.kt

@@ -1,7 +1,5 @@
 package mtmc.os
 
-import java.util.*
-
 enum class SysCall(value: Int) {
   EXIT(0x00),
   RINT(0x01),
@@ -50,25 +48,24 @@ enum class SysCall(value: Int) {
   companion object {
     fun isSysCall(call: String): Boolean {
       try {
-        valueOf(call.uppercase(Locale.getDefault()))
+        valueOf(call.uppercase())
         return true
       } catch (e: IllegalArgumentException) {
         return false
       }
     }
 
-    @JvmStatic
     fun getValue(call: String): Byte {
-      return valueOf(call.uppercase(Locale.getDefault())).value
+      return valueOf(call.uppercase()).value
     }
 
     fun getString(syscallCode: Byte): String? {
       for (o in entries) {
         if (o.value == syscallCode) {
-          return o.name.lowercase(Locale.getDefault())
+          return o.name.lowercase()
         }
       }
       return null
     }
   }
-}
+}

src/commonMain/kotlin/mtmc/os/exec/Executable.kt

@@ -0,0 +1,58 @@
+package mtmc.os.exec
+
+import mtmc.emulator.DebugInfo
+import mtmc.os.fs.Path
+
+data class Executable(
+  val format: Format,
+  val code: ByteArray,
+  val data: ByteArray,
+  val graphics: Array<ByteArray>,
+  val sourceName: String,
+  val debugInfo: DebugInfo?
+) {
+  enum class Format(val formatName: String) {
+    Orc1("orc1");
+  }
+
+  fun dump(): String? {
+    return null //Gson().toJson(this)
+  }
+
+  fun dump(path: Path) {
+    /*
+        FileWriter(path.toFile()).use { fw ->
+          dump(fw)
+        }
+    */
+  }
+
+  /*
+    fun dump(writer: Writer?) {
+      val gson = Gson()
+      gson.toJson(this, writer)
+    }
+  */
+
+  companion object {
+    fun load(exe: String?): Executable? {
+      return null //Gson().fromJson<Executable?>(exe, Executable::class.java)
+    }
+
+    fun load(path: Path): Executable? = null
+    /*
+        {
+          FileReader(path.toFile()).use { fw ->
+            return load(fw)
+          }
+        }
+    */
+
+    /*
+        fun load(reader: Reader): Executable? {
+          val gson = Gson()
+          return gson.fromJson<Executable?>(reader, Executable::class.java)
+        }
+    */
+  }
+}

src/commonMain/kotlin/mtmc/os/fs/Console.kt

@@ -0,0 +1,11 @@
+package mtmc.os.fs
+
+object System {
+  val console: Console = Console()
+}
+
+class Console {
+  fun readLine(prompt: String? = ""): String {
+    TODO("Not yet implemented")
+  }
+}

src/commonMain/kotlin/mtmc/os/fs/File.kt

@@ -0,0 +1,43 @@
+package mtmc.os.fs
+
+object Files {
+  fun readString(toPath: Path): String {
+    TODO("Not yet implemented")
+  }
+
+  fun readAllBytes(toPath: Path): ByteArray {
+    TODO("Not yet implemented")
+  }
+
+}
+
+class File(
+  val parent: File? = null,
+  val name: String
+) {
+
+  var directory: Boolean = false
+
+  constructor(name: String) : this(null, name)
+
+  fun getPath(): String = if (parent == null) {
+    name
+  } else {
+    "${parent.getPath()}/$name"
+  }
+
+  fun exists(): Boolean = true
+
+  fun getAbsolutePath(): String {
+    TODO("Not yet implemented")
+  }
+
+  fun toPath(): Path {
+    TODO("Not yet implemented")
+  }
+
+  fun listFiles(): Array<File> {
+    TODO("Not yet implemented")
+  }
+
+}

src/commonMain/kotlin/mtmc/os/fs/FileSystem.kt

@@ -0,0 +1,213 @@
+package mtmc.os.fs
+
+import mtmc.emulator.MonTanaMiniComputer
+import kotlin.jvm.JvmField
+
+class FileSystem(
+  val computer: MonTanaMiniComputer
+) {
+  private var cwd = "/home"
+
+  init {
+    initFileSystem()
+  }
+
+  private fun initFileSystem() {
+    /*
+        if (DISK_PATH.toFile().exists()) return
+
+
+        // Make the disk/ directory
+        DISK_PATH.toFile().mkdirs()
+
+        try {
+          ZipInputStream(getClass().getResourceAsStream("/disk.zip")).use { `in` ->
+            var entry: ZipEntry?
+            var file: File?
+
+            val data = ByteArray(4096)
+            var count: Int
+            while ((`in`.getNextEntry().also { entry = it }) != null) {
+              file = File(entry.getName())
+
+              if (entry.isDirectory()) {
+                file.mkdirs()
+              } else {
+                file.getParentFile().mkdirs()
+
+                FileOutputStream(file).use { out ->
+                  while ((`in`.read(data).also { count = it }) > 0) {
+                    out.write(data, 0, count)
+                  }
+                }
+              }
+            }
+          }
+        } catch (e: IOException) {
+          e.printStackTrace()
+        }
+    */
+  }
+
+  private fun notifyOfFileSystemUpdate() {
+    if (this.computer != null) {
+      computer.notifyOfFileSystemUpdate()
+    }
+  }
+
+  var cWD: String
+    get() = this.cwd
+    set(cwd) {
+      this.cwd = resolve(cwd)
+      this.notifyOfFileSystemUpdate()
+    }
+
+  fun exists(path: String): Boolean {
+    return false //File(DISK_PATH.toFile(), resolve(path)).exists()
+  }
+
+  fun mkdir(path: String): Boolean {
+    /*
+        val success: Boolean = File(DISK_PATH.toFile(), resolve(path)).mkdir()
+
+        if (success) {
+          computer.notifyOfFileSystemUpdate()
+        }
+
+        return success
+    */
+    return true
+  }
+
+  fun delete(path: String): Boolean {
+    /*
+        val success: Boolean = File(DISK_PATH.toFile(), resolve(path)).delete()
+
+        if (success) {
+          computer.notifyOfFileSystemUpdate()
+        }
+
+        return success
+    */
+    return true
+  }
+
+  fun resolve(filename: String): String = filename
+  /*
+    {
+      val root: File = DISK_PATH.toFile()
+      var directory = if (filename.startsWith("/")) root else File(root, cwd)
+      val path: Array<String> = filename.split("/")
+
+      for (name in path) {
+        if (name.equals(".")) {
+          continue
+        } else if (name.equals("..") && directory.equals(root)) {
+          continue
+        } else if (name.equals("..")) {
+          directory = directory.getParentFile()
+        } else {
+          directory = File(directory, name)
+        }
+      }
+
+      if (directory.equals(root)) {
+        return "/"
+      }
+
+      return directory.getAbsolutePath().substring(root.getAbsolutePath().length())
+    }
+  */
+
+  fun getRealPath(path: String): Path { // Resolves given path and returns /disk/ + path
+    val resolvedPath = resolve(path)
+    val slashGone: String = if (resolvedPath.length > 0) resolvedPath.substring(1) else ""
+    val file: File = DISK_PATH.resolve(slashGone).toFile()
+
+    if (file.getAbsolutePath().length < DISK_PATH.toFile().getAbsolutePath().length) {
+      return DISK_PATH
+    }
+
+    return file.toPath()
+  }
+
+  fun getFileList(path: String): Array<File> {
+    val resolvedPath: File = getRealPath(path).toFile()
+
+    if (!resolvedPath.directory) return arrayOf<File>(resolvedPath)
+
+    return resolvedPath.listFiles()
+  }
+
+  fun listFiles(path: String): Listing {
+    val resolvedPath: File = getRealPath(path).toFile()
+
+    return Listing(this, resolvedPath)
+  }
+
+  fun listCWD(): Listing {
+    return listFiles(cwd)
+  }
+
+  fun listRoot(): Listing {
+    return listFiles("/")
+  }
+
+  fun writeFile(path: String, contents: String?) {
+    val filePath: Path = getRealPath(path)
+    //Files.writeString(filePath, contents)
+  }
+
+  fun readFile(path: String): String? {
+    val filePath: Path = getRealPath(path)
+    val contents = ""  //Files.readString(filePath)
+    return contents
+  }
+
+  fun getMimeType(path: String): String {
+    val file: Path = getRealPath(path)
+    val name = file.toFile().name.lowercase()
+    val probed = file.probeContentType()
+
+    if (name.endsWith(".asm")) return "text/x-asm"
+    if (name.endsWith(".c")) return "text/x-csrc"
+    if (name.endsWith(".sea")) return "text/x-csrc"
+    if (name.endsWith(".h")) return "text/x-csrc"
+    if (probed != null) return probed
+
+    return "application/octet-stream"
+  }
+
+  /*
+    fun openFile(path: String): InputStream? {
+      val file: Unit */
+  /* TODO: class org.jetbrains.kotlin.nj2k.types.JKJavaNullPrimitiveType *//*
+? =
+      getRealPath(path).toFile()
+
+    return FileInputStream(file)
+  }
+*/
+
+  /*
+    fun saveFile(path: String, contents: InputStream) {
+      val file: Unit */
+  /* TODO: class org.jetbrains.kotlin.nj2k.types.JKJavaNullPrimitiveType *//*
+? =
+      getRealPath(path).toFile()
+    val data = ByteArray(4096)
+    var count: Int
+
+    FileOutputStream(file).use { out ->
+      while ((contents.read(data).also { count = it }) > 0) {
+        out.write(data, 0, count)
+      }
+    }
+  }
+*/
+
+  companion object {
+    @JvmField
+    val DISK_PATH: Path = Path() //.of(System.getProperty("user.dir"), "disk").toAbsolutePath()
+  }
+}

src/commonMain/kotlin/mtmc/os/fs/Listing.kt

@@ -0,0 +1,45 @@
+package mtmc.os.fs
+
+class Listing(
+  val fs: FileSystem,
+  val file: File
+) {
+  val path: String
+  val name: String
+  val directory: Boolean
+  val root: Boolean
+
+  init {
+    val root = FileSystem.DISK_PATH.toFile().getAbsolutePath().replace('\\', '/')
+    val path = file.getAbsolutePath().substring(root.length).replace('\\', '/')
+
+    this.path = if (path.length > 0) path else "/"
+    this.name = if (path.length > 0) file.name else "/"
+    this.directory = file.directory
+    this.root = this.path.equals("/")
+  }
+
+  val parent: Listing?
+    get() = if (file.parent != null) {
+      Listing(fs, file.parent)
+    } else {
+      null
+    }
+
+  fun list(): List<Listing> {
+    if (!directory) {
+      return ArrayList()
+    }
+
+    val list = ArrayList<Listing>()
+    val children = file.listFiles()
+
+    list.sortBy { it.name }
+
+    for (child in children) {
+      list.add(Listing(fs, child))
+    }
+
+    return list
+  }
+}

src/commonMain/kotlin/mtmc/os/fs/Path.kt

@@ -0,0 +1,25 @@
+package mtmc.os.fs
+
+class Path {
+  fun toFile(): File {
+    TODO("Not yet implemented")
+  }
+
+  fun probeContentType(): String? {
+    TODO("Not yet implemented")
+  }
+
+  fun resolve(filename: String): Path {
+    TODO("Not yet implemented")
+  }
+
+  fun toAbsolutePath(): Path {
+    TODO("Not yet implemented")
+  }
+
+  companion object {
+    fun of(string: String): Path {
+      TODO()
+    }
+  }
+}

src/commonMain/kotlin/mtmc/os/shell/Shell.kt

@@ -0,0 +1,165 @@
+package mtmc.os.shell
+
+import mtmc.asm.Assembler
+import mtmc.asm.instructions.Instruction.Companion.isInstruction
+import mtmc.asm.peekFirst
+import mtmc.emulator.MonTanaMiniComputer
+import mtmc.emulator.Register
+import mtmc.os.fs.FileSystem
+import mtmc.os.shell.builtins.AssembleCommand
+import mtmc.os.shell.builtins.DisplayCommand
+import mtmc.os.shell.builtins.ExitCommand
+import mtmc.os.shell.builtins.GetCommand
+import mtmc.os.shell.builtins.HelpCommand
+import mtmc.os.shell.builtins.LoadCommand
+import mtmc.os.shell.builtins.PauseCommand
+import mtmc.os.shell.builtins.RunCommand
+import mtmc.os.shell.builtins.SeacCommand
+import mtmc.os.shell.builtins.SetCommand
+import mtmc.os.shell.builtins.SpeedCommand
+import mtmc.os.shell.builtins.StepCommand
+import mtmc.os.shell.builtins.WebCommand
+import mtmc.tokenizer.MTMCToken
+import mtmc.tokenizer.MTMCTokenizer
+
+object Shell {
+  private val COMMANDS: MutableMap<String?, ShellCommand> = LinkedHashMap<String?, ShellCommand>()
+
+  init {
+    COMMANDS.put("help", HelpCommand())
+    COMMANDS.put("exit", ExitCommand())
+    COMMANDS.put("set", SetCommand())
+    COMMANDS.put("get", GetCommand())
+    COMMANDS.put("web", WebCommand())
+    COMMANDS.put("disp", DisplayCommand())
+    COMMANDS.put("asm", AssembleCommand())
+    COMMANDS.put("load", LoadCommand())
+    COMMANDS.put("step", StepCommand())
+    COMMANDS.put("run", RunCommand())
+    COMMANDS.put("pause", PauseCommand())
+    COMMANDS.put("speed", SpeedCommand())
+    COMMANDS.put("sc", SeacCommand())
+  }
+
+  fun isCommand(cmd: String): Boolean {
+    return COMMANDS.containsKey(cmd.lowercase())
+  }
+
+  private fun findExecutable(path: String?, fs: FileSystem): Boolean {
+    if (path == null || path == "") return false
+    //if (fs.exists(path) && !fs.listFiles(path).directory) return true
+    //if (fs.exists("/bin/" + path) && !fs.listFiles("/bin/" + path).directory) return true
+
+    return false
+  }
+
+  @Throws(Exception::class)
+  private fun runExecutable(
+    file: String,
+    command: String,
+    tokens: MTMCTokenizer,
+    computer: MonTanaMiniComputer
+  ) {
+    val fs = computer.fileSystem
+    /*
+        var srcPath = Path.of("disk/" + fs.resolve(file))
+        if (!srcPath.toFile().exists()) {
+          srcPath = Path.of("disk" + fs.resolve("/bin/" + file))
+        }
+        val exec = load(srcPath)
+        computer.load(exec!!.code, exec.data, exec.graphics, exec.debugInfo)
+        tokens.consume()
+        val arg = command.substring(file.length).trim()
+        computer.oS.applyBreakpoints()
+        computer.setArg(arg)
+        computer.run()
+    */
+  }
+
+  fun execCommand(command: String, computer: MonTanaMiniComputer) {
+    println("Exec: $command")
+    val tokens = MTMCTokenizer(command, "#")
+    try {
+      val identifier = tokens.matchAndConsume(MTMCToken.TokenType.IDENTIFIER)
+      val cmd: String?
+      if (identifier == null) {
+        val question = tokens.matchAndConsume(MTMCToken.TokenType.QUESTION_MARK)
+        val executable = tokens.collapseTokensAsString()
+
+
+        // alias ? to help
+        if (question != null) {
+          cmd = "help"
+        } else if (findExecutable(executable, computer.fileSystem)) {
+          cmd = executable
+        } else {
+          printShellHelp(computer)
+          return
+        }
+      } else {
+        cmd = identifier.stringValue
+      }
+      if (isCommand(cmd)) {
+        COMMANDS[cmd.lowercase()]!!.exec(tokens, computer)
+      } else {
+        println("Executing: $command")
+        tokens.reset()
+        val asm = mutableListOf<MTMCToken>()
+        asm.addAll(tokens.tokens)
+        val updatedAsm = Assembler.transformSyntheticInstructions(asm)
+        val firstToken = updatedAsm.peekFirst()
+        val firstTokenStr = firstToken?.stringValue ?: error("Unexpected null token")
+        if (!updatedAsm.isEmpty() && isInstruction(firstTokenStr)) {
+          val assembler = Assembler()
+          val result = assembler.assemble(command)
+          if (result.errors.isEmpty()) {
+            val code = result.code
+            if (code.size == 4) {
+              val data = (code[2].toInt() shl 8) or code[3].toInt()
+              computer.setRegisterValue(Register.DR, data)
+            }
+            val lower = code[1].toInt() and 0xFF
+            val higher = code[0].toInt() and 0xFF
+            val inst = (higher shl 8) or lower
+            val originalDebugInfo = computer.debugInfo
+            computer.debugInfo = result.debugInfo
+            computer.execInstruction(inst.toShort())
+            computer.debugInfo = originalDebugInfo
+          } else {
+            computer.console.println(result.printErrors())
+          }
+        } else {
+          if (findExecutable(cmd, computer.fileSystem)) {
+            runExecutable(cmd, command, tokens, computer)
+          } else {
+            printShellHelp(computer)
+          }
+        }
+      }
+      /*
+          } catch (e: NoSuchFileException) {
+            computer.console.println("No such file: " + e.getFile())
+      */
+    } catch (e: Exception) {
+      computer.console.println(e.message!!)
+      e.printStackTrace()
+    }
+  }
+
+  fun printShellHelp(computer: MonTanaMiniComputer) {
+    computer.console.println("Shell BuiltIns: \n")
+    for (value in COMMANDS.values) {
+      computer.console.println(value.help!!)
+    }
+    computer.console.println("Also: ")
+    computer.console.println("   <asm instruction>")
+    computer.console.println(
+      "or \n" +
+          "  <executable>\n\n"
+    )
+  }
+
+  fun printShellWelcome(computer: MonTanaMiniComputer) {
+    computer.console.println("Welcome to MtOS!  Type ? for help")
+  }
+}

src/commonMain/kotlin/mtmc/os/shell/UsageException.kt

@@ -0,0 +1,7 @@
+package mtmc.os.shell
+
+class UsageException(
+  cmd: ShellCommand
+) : RuntimeException(
+  "Usage:\n\n" + cmd.help
+)

src/commonMain/kotlin/mtmc/os/shell/builtins/AssembleCommand.kt

@@ -0,0 +1,45 @@
+package mtmc.os.shell.builtins
+
+import mtmc.emulator.MonTanaMiniComputer
+import mtmc.os.shell.ShellCommand
+import mtmc.tokenizer.MTMCTokenizer
+
+class AssembleCommand : ShellCommand() {
+  @Throws(Exception::class)
+  public override fun exec(tokens: MTMCTokenizer, computer: MonTanaMiniComputer) {
+    val fs = computer.fileSystem
+    val src = tokens.collapseTokensAsString()
+    require(!(src == null || src.isBlank())) { "missing or required argument 'src'" }
+    /*
+        val srcPath: Path = getDiskPath(src, fs)
+
+        val dst = tokens.collapseTokensAsString()
+        require(!(dst == null || dst.isBlank())) { "missing required argument 'dst'" }
+        val dstPath: Path = getDiskPath(dst, fs)
+
+        val contents = Files.readString(srcPath)
+        val assembler = Assembler()
+        val file_name =
+          fs.resolve(src) // srcPath.toString().substring(DISK_PATH.toString().length()).replaceAll("\\\\", "/");
+        val executable = assembler.assembleExecutable(file_name, contents)
+        executable.dump(dstPath)
+        computer.notifyOfFileSystemUpdate()
+    */
+  }
+
+  override val help: String
+    get() = """
+                asm <src> <dst>
+                    - src : path to a .asm file
+                    - dst : path to a target output binary
+                    """.trimIndent()
+
+  companion object {
+    /*
+        fun getDiskPath(pathString: String, fs: FileSystem): Path {
+          val path = Path.of("disk" + fs.resolve(pathString))
+          return path.toAbsolutePath()
+        }
+    */
+  }
+}

src/commonMain/kotlin/mtmc/os/shell/builtins/DisplayCommand.kt

@@ -2,15 +2,14 @@ package mtmc.os.shell.builtins
 
 import mtmc.emulator.MTMCDisplay
 import mtmc.emulator.MonTanaMiniComputer
+import mtmc.os.fs.File
 import mtmc.os.shell.ShellCommand
 import mtmc.tokenizer.MTMCToken
 import mtmc.tokenizer.MTMCTokenizer
-import java.io.File
-import java.util.*
-import javax.imageio.ImageIO
+import kotlin.random.Random
 
 class DisplayCommand : ShellCommand() {
-  var random: Random = Random()
+  var random: Random = Random.Default
 
   @Throws(Exception::class)
   public override fun exec(tokens: MTMCTokenizer, computer: MonTanaMiniComputer) {
@@ -42,8 +41,8 @@ class DisplayCommand : ShellCommand() {
           if (tokens.more()) {
             val imagePath = tokens.collapseTokensAsString()
             val file = computer.oS.loadFile(imagePath)
-            val img = ImageIO.read(file)
-            computer.display.loadScaledImage(img)
+            //val img = ImageIO.read(file)
+            //computer.display.loadScaledImage(img)
           } else {
             usageException()
           }
@@ -54,11 +53,15 @@ class DisplayCommand : ShellCommand() {
     } else if (tokens.match(MTMCToken.TokenType.INTEGER)) {
       val row = tokens.consumeAsInteger()
       val col = tokens.require(
-        mtmc.tokenizer.MTMCToken.TokenType.INTEGER,
-        java.lang.Runnable { this.usageException() })!!.intValue()
+        mtmc.tokenizer.MTMCToken.TokenType.INTEGER
+      ) {
+        this.usageException()
+      }!!.intValue()
       val color = tokens.require(
-        mtmc.tokenizer.MTMCToken.TokenType.INTEGER,
-        java.lang.Runnable { this.usageException() })!!.intValue()
+        mtmc.tokenizer.MTMCToken.TokenType.INTEGER
+      ) {
+        this.usageException()
+      }!!.intValue()
       computer.display.setPixel(row, col, color)
     } else {
       usageException()

src/commonMain/kotlin/mtmc/os/shell/builtins/ExitCommand.kt

@@ -7,7 +7,7 @@ import mtmc.tokenizer.MTMCTokenizer
 class ExitCommand : ShellCommand() {
   public override fun exec(tokens: MTMCTokenizer, computer: MonTanaMiniComputer) {
     computer.console.println("Goodbye!")
-    System.exit(1)
+    //System.exit(1)
   }
 
   override val help: String

src/commonMain/kotlin/mtmc/os/shell/builtins/GetCommand.kt

@@ -17,11 +17,11 @@ class GetCommand : ShellCommand() {
     if (memLocation == null) {
       val register = tokens.matchAndConsume(MTMCToken.TokenType.IDENTIFIER)
       if (register == null) usageException()
-      val reg = Register.toInteger(register!!.stringValue())
+      val reg = Register.toInteger(register!!.stringValue)
       if (reg >= 0) {
-        computer.console.println(register.stringValue() + ": " + computer.getRegisterValue(reg))
+        computer.console.println(register.stringValue + ": " + computer.getRegisterValue(reg))
       } else {
-        throw IllegalArgumentException("Bad register: " + register.stringValue())
+        throw IllegalArgumentException("Bad register: " + register.stringValue)
       }
     } else {
       if (memLocation.type === MTMCToken.TokenType.INTEGER || memLocation.type === MTMCToken.TokenType.BINARY || memLocation.type === MTMCToken.TokenType.HEX) {

src/commonMain/kotlin/mtmc/os/shell/builtins/LoadCommand.kt

@@ -3,13 +3,13 @@ package mtmc.os.shell.builtins
 import mtmc.emulator.MonTanaMiniComputer
 import mtmc.os.exec.Executable.Companion.load
 import mtmc.os.fs.FileSystem
+import mtmc.os.fs.Path
 import mtmc.os.shell.ShellCommand
 import mtmc.tokenizer.MTMCTokenizer
-import java.nio.file.Path
 
 class LoadCommand : ShellCommand() {
   @Throws(Exception::class)
-  public override fun exec(tokens: MTMCTokenizer, computer: MonTanaMiniComputer) {
+  override fun exec(tokens: MTMCTokenizer, computer: MonTanaMiniComputer) {
     val fs = computer.fileSystem
     val program = tokens.collapseTokensAsString()
     require(!(program == null || program.isBlank())) { "missing or required argument 'src'" }

src/commonMain/kotlin/mtmc/os/shell/builtins/SeacCommand.kt

@@ -1,10 +1,8 @@
 package mtmc.os.shell.builtins
 
 import mtmc.emulator.MonTanaMiniComputer
-import mtmc.lang.sea.SeaLanguage
 import mtmc.os.shell.ShellCommand
 import mtmc.tokenizer.MTMCTokenizer
-import mtmc.util.StringEscapeUtils.escapeString
 
 class SeacCommand : ShellCommand() {
   @Throws(Exception::class)
@@ -24,15 +22,18 @@ class SeacCommand : ShellCommand() {
 
     requireNotNull(filename) { "expected source file" }
 
-    require(fs.exists(filename)) { "file " + escapeString(filename) + " does not exist" }
+    require(fs.exists(filename)) { "file " + filename + " does not exist" }
     println(fs.resolve(filename))
-    val lang = SeaLanguage()
-    val content = fs.readFile(filename)
-    val exec = lang.compileExecutable(fs.resolve(filename), content)
 
-    val bin = exec.dump()
-    computer.fileSystem.writeFile(output, bin)
-    computer.notifyOfFileSystemUpdate()
+    /*
+        val lang = SeaLanguage()
+        val content = fs.readFile(filename)
+        val exec = lang.compileExecutable(fs.resolve(filename), content)
+
+        val bin = exec.dump()
+        computer.fileSystem.writeFile(output, bin)
+        computer.notifyOfFileSystemUpdate()
+    */
   }
 
   override val help: String

src/commonMain/kotlin/mtmc/os/shell/builtins/SetCommand.kt

@@ -23,11 +23,11 @@ class SetCommand : ShellCommand() {
         MTMCToken.TokenType.BINARY
       )
       if (value == null) usageException()
-      val reg = Register.toInteger(register!!.stringValue())
+      val reg = Register.toInteger(register!!.stringValue)
       if (reg >= 0) {
         computer.setRegisterValue(reg, value!!.intValue())
       } else {
-        throw IllegalArgumentException("Bad register: " + register.stringValue())
+        throw IllegalArgumentException("Bad register: " + register.stringValue)
       }
     } else {
       val value = tokens.matchAndConsume(
@@ -40,7 +40,10 @@ class SetCommand : ShellCommand() {
       if (value?.type === MTMCToken.TokenType.INTEGER || value?.type === MTMCToken.TokenType.BINARY || value?.type === MTMCToken.TokenType.HEX) {
         computer.writeWordToMemory(memLocation.intValue(), value.intValue())
       } else {
-        computer.writeStringToMemory(memLocation.intValue(), value!!.stringValue().toByteArray())
+        computer.writeStringToMemory(
+          memLocation.intValue(),
+          value!!.stringValue.encodeToByteArray()
+        )
       }
     }
   }

src/commonMain/kotlin/mtmc/os/shell/builtins/SpeedCommand.kt

@@ -4,13 +4,10 @@ import mtmc.emulator.MonTanaMiniComputer
 import mtmc.os.shell.ShellCommand
 import mtmc.tokenizer.MTMCToken
 import mtmc.tokenizer.MTMCTokenizer
-import java.util.*
 
 class SpeedCommand : ShellCommand() {
-  private val speeds: MutableList<Int?> = Arrays.asList<Int?>(
-    *arrayOf<Int>(
+  private val speeds = listOf(
       1, 10, 100, 1000, 10000, 100000, 1000000
-    )
   )
 
   @Throws(Exception::class)

src/commonMain/kotlin/mtmc/tokenizer/MTMCScanner.kt

@@ -1,14 +1,16 @@
 package mtmc.tokenizer
 
-import java.util.*
+fun Char.isHexDigit(): Boolean {
+  return this in '0'..'9' || this in 'a'..'f' || this in 'A'..'F'
+}
 
 class MTMCScanner(private val src: String, private val lineCommentStart: String) {
   var position: Int = 0
   var line: Int = 1
   var lineOffset: Int = 0
-  var tokens: LinkedList<MTMCToken> = LinkedList<MTMCToken>()
+  var tokens = mutableListOf<MTMCToken>()
 
-  fun tokenize(): LinkedList<MTMCToken> {
+  fun tokenize(): MutableList<MTMCToken> {
     consumeWhitespace()
     while (!scanEnd()) {
       scanToken()
@@ -38,7 +40,7 @@ class MTMCScanner(private val src: String, private val lineCommentStart: String)
   }
 
   private fun scanLineComment(): Boolean {
-    val bytes = lineCommentStart.toByteArray()
+    val bytes = lineCommentStart.encodeToByteArray()
     for (i in bytes.indices) {
       val aChar = bytes[i]
       if (peek(i).code.toByte() != aChar) {
@@ -188,7 +190,7 @@ class MTMCScanner(private val src: String, private val lineCommentStart: String)
   private fun scanHex(start: Int): Boolean {
     takeChar() // take leading zero
     takeChar() // take 'x'
-    while (HexFormat.isHexDigit(peek().code)) {
+    while (peek().isHexDigit()) {
       takeChar()
     }
     tokens.add(makeToken(MTMCToken.TokenType.HEX, strValueFrom(start), start))

src/commonMain/kotlin/mtmc/tokenizer/MTMCToken.kt

@@ -1,22 +1,17 @@
 package mtmc.tokenizer
 
-@JvmRecord
 data class MTMCToken(
-  @JvmField val start: Int,
-  @JvmField val end: Int,
+  val start: Int,
+  val end: Int,
   val line: Int,
   val lineOffset: Int,
-  @JvmField val stringValue: String,
-  @JvmField val type: TokenType?
+  val stringValue: String,
+  val type: TokenType?
 ) {
   override fun toString(): String {
     return stringValue
   }
 
-  fun stringValue(): String {
-    return stringValue
-  }
-
   fun charValue(): Char {
     return stringValue.get(0)
   }

src/commonMain/kotlin/mtmc/tokenizer/MTMCTokenizer.kt

@@ -1,14 +1,13 @@
 package mtmc.tokenizer
 
-import java.util.*
-import java.util.stream.Stream
+import mtmc.util.Runnable
 import kotlin.math.max
 
 class MTMCTokenizer(var source: String, lineCommentStart: String) {
-  var tokens: LinkedList<MTMCToken> = MTMCScanner(source, lineCommentStart).tokenize()
+  var tokens: MutableList<MTMCToken> = MTMCScanner(source, lineCommentStart).tokenize()
   var currentToken: Int = 0
 
-  fun currentToken(): MTMCToken {
+  fun getCurrentToken(): MTMCToken {
     return tokens.get(currentToken)
   }
 
@@ -29,8 +28,8 @@ class MTMCTokenizer(var source: String, lineCommentStart: String) {
   }
 
   fun matchAndConsume(identifier: String?): Boolean {
-    if (currentToken().type == MTMCToken.TokenType.IDENTIFIER &&
-      currentToken().stringValue == identifier
+    if (getCurrentToken().type == MTMCToken.TokenType.IDENTIFIER &&
+      getCurrentToken().stringValue == identifier
     ) {
       return true
     } else {
@@ -40,7 +39,7 @@ class MTMCTokenizer(var source: String, lineCommentStart: String) {
 
   fun match(vararg type: MTMCToken.TokenType?): Boolean {
     for (tokenType in type) {
-      if (currentToken().type == tokenType) {
+      if (getCurrentToken().type == tokenType) {
         return true
       }
     }
@@ -52,17 +51,13 @@ class MTMCTokenizer(var source: String, lineCommentStart: String) {
   }
 
   fun more(): Boolean {
-    return currentToken().type != MTMCToken.TokenType.EOF
+    return getCurrentToken().type != MTMCToken.TokenType.EOF
   }
 
   fun previousToken(): MTMCToken? {
     return tokens.get(max(0, currentToken - 1))
   }
 
-  fun stream(): Stream<MTMCToken?> {
-    return tokens.stream()
-  }
-
   override fun toString(): String {
     val sb = StringBuilder()
     for (i in tokens.indices) {
@@ -88,7 +83,7 @@ class MTMCTokenizer(var source: String, lineCommentStart: String) {
       do {
         last = consume()
         sb.append(last.stringValue)
-        next = currentToken()
+        next = getCurrentToken()
       } while (more() && last.end == next.start)
       return sb.toString()
     } else {
@@ -104,7 +99,7 @@ class MTMCTokenizer(var source: String, lineCommentStart: String) {
     if (match(tokenType)) {
       return consume()
     } else {
-      notFound.run()
+      notFound.invoke()
       return null
     }
   }

src/commonMain/kotlin/mtmc/util/BinaryUtils.kt

@@ -11,38 +11,28 @@ object BinaryUtils {
       return 0
     }
     val returnValue = (value.toInt() and 0xffff) ushr (start - totalBits)
-    var mask = 0
-    var toShift = totalBits
-    while (toShift > 0) {
-      toShift--
-      mask = mask shl 1
-      mask = mask + 1
-    }
+    var mask = 1
+    mask = mask shl totalBits
+    mask--
     return (returnValue and mask).toShort()
   }
 
   fun toBinary(aByte: Byte): String {
-    val binaryString = Integer.toBinaryString(aByte.toInt())
-    val formatted = String.format("%8s", binaryString)
-    val zeroed = formatted.replace(" ".toRegex(), "0")
+    val zeroed = aByte.toInt().toString(2).padStart(8, '0')
     val underScored = zeroed.replace("....".toRegex(), "$0_")
     val noTrailingUnderscore = underScored.substring(0, underScored.length - 1)
     return "0b" + noTrailingUnderscore
   }
 
   fun toBinary(aShort: Short): String {
-    val binaryString = Integer.toBinaryString(aShort.toInt())
-    val formatted = String.format("%16s", binaryString)
-    val zeroed = formatted.replace(" ".toRegex(), "0")
+    val zeroed = aShort.toInt().toString(2).padStart(16, '0')
     val underScored = zeroed.replace("....".toRegex(), "$0_")
     val noTrailingUnderscore = underScored.substring(0, underScored.length - 1)
     return "0b" + noTrailingUnderscore
   }
 
   fun toBinary(anInt: Int): String {
-    val binaryString = Integer.toBinaryString(anInt)
-    val formatted = String.format("%32s", binaryString)
-    val zeroed = formatted.replace(" ".toRegex(), "0")
+    val zeroed = anInt.toString(2).padStart(32, '0')
     val underScored = zeroed.replace("....".toRegex(), "$0_")
     val noTrailingUnderscore = underScored.substring(0, underScored.length - 1)
     return "0b" + noTrailingUnderscore

src/commonMain/kotlin/mtmc/util/PlatformSpecific.kt

@@ -0,0 +1,11 @@
+package mtmc.util
+
+expect fun currentTimeMillis(): Double
+
+expect fun time(): Double
+
+expect fun requestAnimationFrame(action: (Double) -> Unit)
+
+expect fun setTimeout(action: () -> Unit)
+
+expect fun immediateTimeout(action: (Double) -> Unit): Int

src/commonMain/kotlin/mtmc/util/Runnable.kt

@@ -0,0 +1,3 @@
+package mtmc.util
+
+typealias Runnable = () -> Unit

src/jsMain/kotlin/mtmc/Main.kt

@@ -1,18 +1,43 @@
 package mtmc
 
 import kotlinx.browser.document
-import kotlinx.html.div
-import nl.astraeus.komp.HtmlBuilder
+import kotlinx.browser.window
+import mtmc.emulator.MonTanaMiniComputer
+import mtmc.util.currentTimeMillis
+import mtmc.view.DisplayView
+import mtmc.view.MTMCView
 import nl.astraeus.komp.Komponent
 
-class HelloKomponent : Komponent() {
-  override fun HtmlBuilder.render() {
-    div {
-      + "Hello, world!"
-    }
-  }
-}
+val computer = MonTanaMiniComputer()
+val mainView = MTMCView(computer)
+val display = DisplayView(computer)
 
 fun main() {
-  Komponent.create(document.body!!, HelloKomponent())
+  computer.speed = 1000000
+  computer.load(lifeCode, lifeData)
+  //computer.load(snakeCode, snakeData)
+
+  Komponent.create(document.body!!, mainView)
+
+  computer.start()
+
+  mainView.requestUpdate()
+  display.requestUpdate()
+
+  window.requestAnimationFrame { updateJsDisplay() }
+}
+
+var lastMemoryUpdate = currentTimeMillis()
+var updateState = true
+
+fun updateJsDisplay() {
+  display.requestUpdate()
+  if (currentTimeMillis() - lastMemoryUpdate > 125) {
+    if (updateState) {
+      mainView.registerView.requestUpdate()
+      mainView.memoryView.requestUpdate()
+    }
+    lastMemoryUpdate = currentTimeMillis()
+  }
+  window.requestAnimationFrame { updateJsDisplay() }
 }

src/jsMain/kotlin/mtmc/emulator/BufferedImage.js.kt

@@ -0,0 +1,116 @@
+package mtmc.emulator
+
+import kotlinx.browser.document
+import org.khronos.webgl.Uint8Array
+import org.khronos.webgl.get
+import org.khronos.webgl.set
+import org.w3c.dom.CanvasRenderingContext2D
+import org.w3c.dom.HTMLCanvasElement
+import org.w3c.dom.ImageData
+
+actual fun createBufferedImage(
+  width: Int,
+  height: Int
+): BufferedImage = BufferedImageImpl(width, height, 1)
+
+class BufferedImageImpl(
+  override val width: Int,
+  override val height: Int,
+  val type: Int
+) : BufferedImage {
+  val display = ByteArray(width * height * 4)
+
+  override fun getRGB(x: Int, y: Int): Int {
+    check(x in 0 until width && y in 0 until height)
+
+    val offset = (x + y * width) * 4
+    return display[offset + 0].toInt() +
+        display[offset + 1].toInt() shl 8 +
+        display[offset + 2].toInt() shl 16
+  }
+
+  override fun setRGB(x: Int, y: Int, intVal: Int) {
+    check(x in 0 until width && y in 0 until height)
+
+    val offset = (x + y * width) * 4
+    display[offset + 0] = (intVal shr 16).toByte()
+    display[offset + 1] = (intVal shr 8).toByte()
+    display[offset + 2] = intVal.toByte()
+    display[offset + 3] = 255.toByte()
+  }
+}
+
+class BufferedImageData(
+  val imageData: ImageData,
+) : BufferedImage {
+  override val width: Int = imageData.width
+  override val height: Int = imageData.height
+
+  override fun getRGB(x: Int, y: Int): Int {
+    check(x in 0 until width && y in 0 until height)
+
+    val offset = (x * 4 + y * width * 4)
+    val display = imageData.data
+    return (display[offset + 0].toInt() and 0xff) shl 16 +
+        (display[offset + 1].toInt() and 0xff) shl 8 +
+        (display[offset + 2].toInt() and 0xff)
+  }
+
+  override fun setRGB(x: Int, y: Int, intVal: Int) {
+    check(x in 0 until width && y in 0 until height)
+
+    val offset = (x * 4 + y * width * 4)
+    val display = imageData.data
+    display[offset + 0] = ((intVal shr 16) and 0xff).toShort().asDynamic()
+    display[offset + 1] = ((intVal shr 8) and 0xff).toShort().asDynamic()
+    display[offset + 2] = (intVal and 0xff).toShort().asDynamic()
+    display[offset + 3] = 255.toShort().asDynamic()
+  }
+}
+
+class BufferedImageDataWebGl(
+  override val width: Int,
+  override val height: Int,
+  val data: Uint8Array = Uint8Array(width * height * 4)
+) : BufferedImage {
+  init {
+    for (x in 0 until width) {
+      for (y in 0 until height) {
+        val offset = (x * 4 + y * width * 4)
+        data[offset + 3] = 255.toShort().asDynamic()
+      }
+    }
+  }
+
+  override fun getRGB(x: Int, y: Int): Int {
+    check(x in 0 until width && y in 0 until height)
+
+    val offset = (x * 4 + y * width * 4)
+    val display = data
+    return (display[offset + 0].toInt() and 0xff) shl 16 +
+        (display[offset + 1].toInt() and 0xff) shl 8 +
+        (display[offset + 2].toInt() and 0xff) shl 0 + 255
+  }
+
+  override fun setRGB(x: Int, y: Int, intVal: Int) {
+    check(x in 0 until width && y in 0 until height)
+
+    val offset = (x * 4 + y * width * 4)
+
+    data[offset + 0] = ((intVal shr 16) and 0xff).toShort().asDynamic()
+    data[offset + 1] = ((intVal shr 8) and 0xff).toShort().asDynamic()
+    data[offset + 2] = ((intVal shr 0) and 0xff).toShort().asDynamic()
+    //data[offset + 3] = 255.toShort().asDynamic()
+  }
+}
+
+val canvas = document.createElement("canvas") as HTMLCanvasElement
+val ctx = canvas.getContext("2d") as CanvasRenderingContext2D
+
+actual fun createCanvasImage(width: Int, height: Int): BufferedImage {
+  return BufferedImageData(ctx.createImageData(width.toDouble(), height.toDouble()));
+}
+
+actual fun createGLImage(width: Int, height: Int): BufferedImage {
+  return BufferedImageDataWebGl(width, height)
+}

src/jsMain/kotlin/mtmc/util/PlatformSpecific.js.kt

@@ -0,0 +1,19 @@
+package mtmc.util
+
+import kotlinx.browser.window
+import kotlin.js.Date
+
+actual fun currentTimeMillis(): Double = Date().getTime()
+actual fun requestAnimationFrame(action: (Double) -> Unit) {
+  window.requestAnimationFrame {
+    action(it)
+  }
+}
+
+actual fun immediateTimeout(action: (Double) -> Unit): Int = window.setTimeout(action, 0)
+
+actual fun time(): Double = window.performance.now()
+
+actual fun setTimeout(action: () -> Unit) {
+  window.setTimeout(action)
+}

src/jsMain/kotlin/mtmc/view/ConsoleView.kt

@@ -0,0 +1,86 @@
+package mtmc.view
+
+import kotlinx.browser.window
+import kotlinx.html.div
+import kotlinx.html.input
+import kotlinx.html.js.onClickFunction
+import kotlinx.html.js.onKeyUpFunction
+import kotlinx.html.span
+import mtmc.display
+import mtmc.emulator.MonTanaMiniComputer
+import mtmc.mainView
+import mtmc.os.shell.Shell
+import nl.astraeus.komp.HtmlBuilder
+import nl.astraeus.komp.Komponent
+import nl.astraeus.komp.currentElement
+import org.w3c.dom.HTMLInputElement
+import org.w3c.dom.events.KeyboardEvent
+
+class ConsoleView(
+  val computer: MonTanaMiniComputer
+) : Komponent() {
+  var input: String = ""
+  var output = StringBuilder()
+  private var inputElement: HTMLInputElement? = null
+
+  init {
+    output.append(computer.console.consumeLines())
+  }
+
+  override fun HtmlBuilder.render() {
+    div("console") {
+      onClickFunction = {
+        inputElement?.focus()
+      }
+      div("console-history") {
+        div {
+          +output.toString()
+        }
+      }
+      div("console-input") {
+        span("console-prompt") {
+          +"mtmc$"
+        }
+        input(classes = "console-input") {
+          value = input
+          autoFocus = true
+          inputElement = currentElement() as? HTMLInputElement
+          currentElement().scrollIntoView()
+          window.setTimeout({
+            inputElement?.focus()
+          }, 0)
+          onKeyUpFunction = { it ->
+            (it as? KeyboardEvent)?.let { ke ->
+              (ke.target as? HTMLInputElement)?.let { inp ->
+                if (ke.key == "Enter") {
+                  handleCommand()
+                } else {
+                  input = inp.value
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+
+  private fun handleCommand() {
+    computer.console.print("mtmc$ ")
+    computer.console.println(input)
+
+    Shell.execCommand(input, computer)
+
+    input = ""
+    output.append(computer.console.consumeLines())
+    if (output.length > 1000 && output.contains("\n")) {
+      output = output.deleteRange(0, output.indexOf("\n"))
+    }
+
+    mainView.registerView.requestUpdate()
+    mainView.memoryView.requestUpdate()
+    display.requestUpdate()
+    requestUpdate()
+  }
+
+}

src/jsMain/kotlin/mtmc/view/ControlView.kt

@@ -0,0 +1,157 @@
+package mtmc.view
+
+import kotlinx.html.InputType
+import kotlinx.html.button
+import kotlinx.html.div
+import kotlinx.html.i
+import kotlinx.html.input
+import kotlinx.html.js.onChangeFunction
+import kotlinx.html.js.onClickFunction
+import kotlinx.html.label
+import kotlinx.html.option
+import kotlinx.html.select
+import kotlinx.html.span
+import mtmc.display
+import mtmc.emulator.MonTanaMiniComputer
+import mtmc.mainView
+import mtmc.updateState
+import nl.astraeus.komp.HtmlBuilder
+import nl.astraeus.komp.Komponent
+import org.w3c.dom.HTMLSelectElement
+import kotlin.text.Typography.nbsp
+
+class ControlView(
+  val computer: MonTanaMiniComputer
+) : Komponent() {
+
+  override fun HtmlBuilder.render() {
+    div("control-panel") {
+      div("control-header") {
+        span {
+          +"m"
+        }
+        span {
+          +"s"
+        }
+        span {
+          +"u"
+        }
+        nbsp
+        i {
+          +"MTMC-16"
+        }
+      }
+      div("control-secondary") {
+        +"MonTana Mini-Computer"
+      }
+      div("control-buttons") {
+        label {
+          +"Update:"
+          htmlFor = "update-state"
+          input {
+            type = InputType.checkBox
+            checked = updateState
+            onClickFunction = {
+              updateState = !updateState
+              requestUpdate()
+            }
+          }
+        }
+        label {
+          select {
+            name = "speed"
+
+            option {
+              value = "1"
+              +"1 Hz"
+            }
+            option {
+              value = "10"
+              +"10 Hz"
+            }
+            option {
+              value = "100"
+              +"100 Hz"
+            }
+            option {
+              value = "1000"
+              +"1 Khz"
+            }
+            option {
+              value = "1000000"
+              selected = true
+              +"1 Mhz"
+            }
+            option {
+              value = "2000000"
+              +"2 Mhz"
+            }
+            option {
+              value = "5000000"
+              +"5 Mhz"
+            }
+            option {
+              value = "10000000"
+              +"10 Mhz"
+            }
+
+            onChangeFunction = {
+              val target = it.target as? HTMLSelectElement
+              target?.value?.toIntOrNull()?.let { speed ->
+                computer.speed = speed
+              }
+            }
+          }
+        }
+
+        // Buttons with fx-* attributes
+        button {
+          if (computer.getStatus() != MonTanaMiniComputer.ComputerStatus.EXECUTING) {
+            +"run"
+            onClickFunction = {
+              computer.run()
+              requestUpdate()
+            }
+          } else {
+            +"pause"
+            onClickFunction = {
+              computer.pause()
+              requestUpdate()
+            }
+          }
+        }
+        button {
+          disabled =
+            computer.getStatus() == MonTanaMiniComputer.ComputerStatus.WAITING && computer.rewindIndex >= 0
+
+          +"back"
+
+          onClickFunction = {
+            computer.back()
+            mainView.requestUpdate()
+            display.requestUpdate()
+          }
+        }
+        button {
+          +"step"
+
+          onClickFunction = {
+            computer.step()
+            mainView.requestUpdate()
+            display.requestUpdate()
+          }
+        }
+        button {
+          +"reset"
+
+          onClickFunction = {
+            computer.initMemory()
+            mainView.requestUpdate()
+            display.requestUpdate()
+          }
+        }
+      }
+    }
+  }
+
+}

src/jsMain/kotlin/mtmc/view/DisplayView.kt

@@ -0,0 +1,173 @@
+package mtmc.view
+
+import kotlinx.html.canvas
+import kotlinx.html.div
+import mtmc.display
+import mtmc.emulator.BufferedImageData
+import mtmc.emulator.BufferedImageDataWebGl
+import mtmc.emulator.MonTanaMiniComputer
+import nl.astraeus.komp.HtmlBuilder
+import nl.astraeus.komp.Komponent
+import nl.astraeus.komp.currentElement
+import org.khronos.webgl.Float32Array
+import org.khronos.webgl.WebGLBuffer
+import org.khronos.webgl.WebGLProgram
+import org.khronos.webgl.WebGLRenderingContext
+import org.khronos.webgl.WebGLShader
+import org.khronos.webgl.WebGLTexture
+import org.w3c.dom.HTMLCanvasElement
+
+// language=GLSL
+val vertexShader = """
+  attribute vec2 a_pos;
+  attribute vec2 a_uv;
+  varying vec2 v_uv;
+  void main() {
+    v_uv = a_uv;
+    gl_Position = vec4(a_pos, 0.0, 1.0);
+  }
+  """
+
+// language=GLSL
+val fragmentShader = """
+  precision mediump float;
+  varying vec2 v_uv;
+  uniform sampler2D u_tex;
+
+  void main() {
+    gl_FragColor = texture2D(u_tex, v_uv);
+  }
+""".trimIndent()
+
+typealias GL = WebGLRenderingContext
+
+class DiplayControlView(
+  val computer: MonTanaMiniComputer
+) : Komponent() {
+
+  override fun HtmlBuilder.render() {
+    div("display") {
+      include(display)
+    }
+  }
+}
+
+class DisplayView(
+  val computer: MonTanaMiniComputer
+) : Komponent() {
+  var ctx: WebGLRenderingContext? = null
+  var program: WebGLProgram? = null
+  var texture: WebGLTexture? = null
+  var buffer: WebGLBuffer? = null
+
+  override fun HtmlBuilder.render() {
+    canvas("display-canvas") {
+      width = "160px"
+      height = "144px"
+
+      val cv = currentElement() as? HTMLCanvasElement
+
+      ctx = cv?.getContext("webgl")?.unsafeCast<WebGLRenderingContext>()
+
+      if (program == null) {
+        createProgram()
+        createBuffer()
+        createTexture()
+      }
+    }
+  }
+
+  private fun createTexture() {
+    ctx?.let { gl: WebGLRenderingContext ->
+      texture = gl.createTexture()
+      gl.bindTexture(GL.TEXTURE_2D, texture)
+
+// Set texture parameters for pixel-perfect rendering
+      gl.texParameteri(GL.TEXTURE_2D, GL.TEXTURE_WRAP_S, GL.CLAMP_TO_EDGE)
+      gl.texParameteri(GL.TEXTURE_2D, GL.TEXTURE_WRAP_T, GL.CLAMP_TO_EDGE)
+      gl.texParameteri(GL.TEXTURE_2D, GL.TEXTURE_MIN_FILTER, GL.NEAREST)
+      gl.texParameteri(GL.TEXTURE_2D, GL.TEXTURE_MAG_FILTER, GL.NEAREST)
+    }
+  }
+
+  private fun createBuffer() {
+    ctx?.let { gl ->
+      // Create quad vertices
+      val vertices = Float32Array(
+        arrayOf(
+          -1f, -1f, 0f, 1f,  // position, texCoord
+          1f, -1f, 1f, 1f,
+          -1f, 1f, 0f, 0f,
+          1f, 1f, 1f, 0f
+        )
+      )
+
+      buffer = gl.createBuffer();
+      gl.bindBuffer(GL.ARRAY_BUFFER, buffer);
+      gl.bufferData(GL.ARRAY_BUFFER, vertices, GL.STATIC_DRAW);
+    }
+  }
+
+
+  private fun createProgram() {
+    val vs = createShader(WebGLRenderingContext.VERTEX_SHADER, vertexShader)
+    val fs = createShader(WebGLRenderingContext.FRAGMENT_SHADER, fragmentShader)
+    val prog = ctx?.createProgram()
+    if (vs != null && fs != null && prog != null) {
+      ctx?.attachShader(prog, vs)
+      ctx?.attachShader(prog, fs)
+      ctx?.linkProgram(prog)
+    }
+    program = prog
+  }
+
+  private fun createShader(type: Int, source: String): WebGLShader? {
+    var result: WebGLShader? = null
+    ctx?.let { gl ->
+      result = gl.createShader(type)
+      result?.let { shader ->
+        gl.shaderSource(shader, source)
+        gl.compileShader(shader)
+      }
+    }
+    return result
+  }
+
+  override fun renderUpdate() {
+    // move data to canvas
+    val buffer = computer.display.buffer
+    if (buffer is BufferedImageData) {
+      //ctx?.putImageData(buffer.imageData, 0.0, 0.0)
+    } else if (buffer is BufferedImageDataWebGl) {
+      ctx?.let { gl ->
+        gl.clear(GL.COLOR_BUFFER_BIT)
+
+        gl.useProgram(program)
+
+        val positionLocation = gl.getAttribLocation(program, "a_pos")
+        val texCoordLocation = gl.getAttribLocation(program, "a_uv")
+
+        gl.bindBuffer(GL.ARRAY_BUFFER, this.buffer)
+        gl.enableVertexAttribArray(positionLocation)
+        gl.vertexAttribPointer(positionLocation, 2, GL.FLOAT, false, 16, 0)
+        gl.enableVertexAttribArray(texCoordLocation)
+        gl.vertexAttribPointer(texCoordLocation, 2, GL.FLOAT, false, 16, 8)
+        gl.bindTexture(GL.TEXTURE_2D, texture);
+        gl.texImage2D(
+          GL.TEXTURE_2D,
+          0,              // level
+          GL.RGBA,         // internal format
+          buffer.width,
+          buffer.height,
+          0,              // border
+          GL.RGBA,         // format
+          GL.UNSIGNED_BYTE, // type
+          buffer.data // data
+        )
+
+        // Draw quad
+        gl.drawArrays(GL.TRIANGLE_STRIP, 0, 4);
+      }
+    }
+  }
+}

src/jsMain/kotlin/mtmc/view/MTMCView.kt

@@ -0,0 +1,34 @@
+package mtmc.view
+
+import kotlinx.html.div
+import mtmc.emulator.MonTanaMiniComputer
+import nl.astraeus.komp.HtmlBuilder
+import nl.astraeus.komp.Komponent
+
+class MTMCView(
+  val computer: MonTanaMiniComputer
+) : Komponent() {
+  val controlView = ControlView(computer)
+  val registerView = RegisterView(computer)
+  val memoryView = MemoryView(computer)
+  val displayView = DiplayControlView(computer)
+  val consoleView = ConsoleView(computer)
+
+  override fun HtmlBuilder.render() {
+    div("container") {
+      div("left-column") {
+        include(controlView)
+        include(registerView)
+        include(memoryView)
+      }
+      div("middle-column") {
+        include(displayView)
+        include(consoleView)
+      }
+      div("right-column") {
+        +"Files"
+      }
+    }
+  }
+
+}

src/jsMain/kotlin/mtmc/view/MemoryView.kt

@@ -0,0 +1,147 @@
+package mtmc.view
+
+import kotlinx.html.classes
+import kotlinx.html.div
+import kotlinx.html.table
+import kotlinx.html.td
+import kotlinx.html.title
+import kotlinx.html.tr
+import mtmc.asm.instructions.Instruction
+import mtmc.emulator.MonTanaMiniComputer
+import mtmc.emulator.Register
+import nl.astraeus.komp.HtmlBuilder
+import nl.astraeus.komp.Komponent
+
+fun ByteArray.asHex(address: Int): String {
+  val value = getShort(address)
+  return value.toHexString()
+}
+
+fun ByteArray.getShort(address: Int): Short {
+  val value = (this[address].toInt() and 0xff) * 256 + (this[address + 1].toInt() and 0xff)
+  return value.toShort()
+}
+
+
+enum class DisplayFormat {
+  DYN,
+  HEX,
+  DEC,
+  INS,
+  STR
+}
+
+private val ASCII_CODES = arrayOf<String>(
+  "NUL", "SOH", "STX", "ETX",
+  "EOT", "ENT", "ACK", "BEL",
+  "BS", "\\t", "\\n", "VT",
+  "\\f", "\\r", "SO", "SI",
+  "DLE", "DC1", "DC2", "DC3",
+  "DC4", "NAK", "SYN", "ETB",
+  "CAN", "EM", "SUB", "ESC",
+  "FS", "GS", "RS", "US",
+)
+
+class MemoryView(
+  val computer: MonTanaMiniComputer
+) : Komponent() {
+  var displayFormat: DisplayFormat = DisplayFormat.DYN
+
+  override fun HtmlBuilder.render() {
+    div("memory-panel") {
+      div("memory-header") {
+        +"Memory"
+      }
+      div("memory") {
+        table {
+          for (baseAddress in 0..<computer.memory.size step 16) {
+            tr {
+              var previousInstruction = 0x0fff.toShort()
+              for (offset in 0..<8) {
+                val address = baseAddress + offset * 2
+                val memoryClass = classFor(address)
+                val df = computeMemoryFormat(memoryClass)
+                val value = computer.memory.getShort(address)
+
+                td {
+                  when (memoryClass) {
+                    "curr" -> classes += "current-address"
+                    "code" -> classes += "code"
+                    "data" -> classes += "data"
+                    "heap" -> classes += "heap"
+                    "sta" -> classes += "stack"
+                  }
+
+                  title = address.toString() + " - " + value.toHexString()
+
+                  when (df) {
+                    DisplayFormat.DEC -> +value.toInt().toString()
+                    DisplayFormat.INS -> {
+                      +Instruction.disassemble(
+                        value,
+                        previousInstruction
+                      )
+                      previousInstruction = value
+                    }
+
+                    DisplayFormat.HEX -> +value.toHexString()
+                    DisplayFormat.STR -> +get1252String(value)
+                    else -> +"?"
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+
+  fun classFor(address: Int): String = if (address >= computer.getRegisterValue(Register.SP)) {
+    "sta"
+  } else if (address == computer.getRegisterValue(Register.PC).toInt()) {
+    "curr"
+  } else if (address <= computer.getRegisterValue(Register.CB)) {
+    "code"
+  } else if (address <= computer.getRegisterValue(Register.DB)) {
+    "data"
+  } else if (address <= computer.getRegisterValue(Register.BP)) {
+    "heap"
+  } else {
+    ""
+  }
+
+  private fun computeMemoryFormat(memoryClass: String?): DisplayFormat {
+    return if (displayFormat == DisplayFormat.DYN) {
+      when (memoryClass) {
+        "sta" -> DisplayFormat.DEC
+        "code", "curr" -> DisplayFormat.INS
+        "data", "heap" -> DisplayFormat.STR
+        else -> DisplayFormat.HEX
+      }
+    } else {
+      displayFormat
+    }
+  }
+
+
+  fun get1252String(value: Short): String {
+    val topByte = (value.toInt() ushr 8).toByte()
+    val bottomByte = value.toByte()
+
+    return if (topByte.toInt() != 0) {
+      get1252String(topByte) + " " + get1252String(
+        bottomByte
+      )
+    } else {
+      get1252String(bottomByte)
+    }
+  }
+
+  private fun get1252String(value: Byte): String = if (value in 0..<32) {
+    ASCII_CODES[value.toInt()]
+  } else {
+    "" + (value.toInt() and 0xff).toChar()
+  }
+
+}

src/jsMain/kotlin/mtmc/view/RegisterView.kt

@@ -0,0 +1,117 @@
+package mtmc.view
+
+import kotlinx.browser.document
+import kotlinx.dom.addClass
+import kotlinx.dom.removeClass
+import kotlinx.html.TABLE
+import kotlinx.html.classes
+import kotlinx.html.div
+import kotlinx.html.hr
+import kotlinx.html.id
+import kotlinx.html.span
+import kotlinx.html.table
+import kotlinx.html.td
+import kotlinx.html.tr
+import mtmc.emulator.MonTanaMiniComputer
+import mtmc.emulator.Register
+import nl.astraeus.komp.HtmlBuilder
+import nl.astraeus.komp.Komponent
+import org.w3c.dom.HTMLElement
+
+class RegisterView(
+  val computer: MonTanaMiniComputer
+) : Komponent() {
+
+  override fun HtmlBuilder.render() {
+    div {
+      table("register-table") {
+        for (index in 0..<16) {
+          showRegister(index)
+        }
+        tr {
+          td {
+            colSpan = "3"
+            hr {}
+          }
+        }
+        showRegister(16)
+        showRegister(17)
+        tr {
+          td("flags") {
+            colSpan = "3"
+            span {
+              +"flags t:"
+
+              div("blinken") {
+                id = "flags-t"
+                if (!computer.isFlagTestBitSet) {
+                  classes += "off"
+                }
+              }
+            }
+            span {
+              +"o:"
+              div("blinken") {
+                id = "flags-o"
+                classes += "off"
+              }
+            }
+            span {
+              +"e:"
+              div("blinken") {
+                id = "flags-e"
+                if (computer.getStatus() != MonTanaMiniComputer.ComputerStatus.PERMANENT_ERROR) {
+                  classes += "off"
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+
+  override fun renderUpdate() {
+    for (register in 0..<18) {
+      val value = computer.registerFile[register]
+      for (bit in 15 downTo 0) {
+        val element = document.getElementById("bit-$bit-$register") as? HTMLElement ?: continue
+        if (value.toInt() and (1 shl bit) == 0) {
+          element.addClass("off")
+        } else {
+          element.removeClass("off")
+        }
+      }
+      val element = document.getElementById("register-$register") as? HTMLElement ?: continue
+      element.innerText = "${value.toInt() and 0xffff}"
+    }
+  }
+
+  private fun TABLE.showRegister(register: Int) {
+    val name = Register.fromInteger(register)
+    val value = computer.registerFile[register]
+    tr {
+      td {
+        +name
+      }
+      td("register-lights") {
+        for (bit in 15 downTo 0) {
+          div("blinken") {
+            id = "bit-$bit-$register"
+            if (value.toInt() and (1 shl bit) == 0) {
+              classes += "off"
+            }
+            if (bit % 4 == 0) {
+              classes += "space"
+            }
+          }
+        }
+      }
+      td("align-right") {
+        id = "register-$register"
+        +"${value.toInt() and 0xffff}"
+      }
+    }
+  }
+
+}

src/jsMain/resources/mtmc.css

@@ -0,0 +1,256 @@
+:root {
+    --pdp-blue: #243571;
+    --pdp-light-blue: #3286ce;
+    --pdp-beige: #fdfddc;
+    --pdp-white: #f1f1f6;
+    --pdp-off-white: #F0EBCD;
+    --filetree-gray: #666;
+}
+
+html, body {
+    padding: 0;
+    margin: 0;
+    box-sizing: border-box;
+}
+
+body {
+    overscroll-behavior: none;
+}
+
+.container {
+    display: grid;
+    grid-template-columns: 450px 450px 1fr;
+    grid-template-rows: 1fr;
+    overflow-y: auto;
+    gap: 5px;
+    background-color: var(--pdp-white);
+}
+
+.left-column {
+    grid-template-rows: auto auto minmax(0, 1fr);
+    display: grid;
+    grid-gap: 4px;
+    height: 100dvh;
+    max-height: 100dvh;
+    min-width: 450px;
+    max-width: 450px;
+}
+
+.middle-column {
+    background-color: #eee;
+    grid-template-rows: auto minmax(0, 1fr);
+    display: grid;
+    grid-gap: 4px;
+    height: 100dvh;
+    max-height: 100dvh;
+    min-width: 450px;
+    max-width: 450px;
+}
+
+.right-column {
+    background-color: #eee;
+    grid-template-rows: auto;
+    display: grid;
+    grid-gap: 4px;
+    height: 100dvh;
+    max-height: 100dvh;
+    min-width: 450px;
+}
+
+.align-right {
+    text-align: right;
+}
+
+/* control */
+
+.control-panel > * {
+    margin: 4px;
+}
+
+.control-header {
+    background-color: var(--pdp-blue);
+    color: var(--pdp-white);
+    font-family: monospace;
+    font-size: 32px;
+    padding: 4px 24px;
+    margin-left: 0;
+    margin-right: 0;
+}
+
+.control-header span {
+    display: inline-block;
+    margin-top: -6px;
+    margin-bottom: -6px;
+    padding: 4px 8px;
+    font-weight: bold;
+    font-size: 38px;
+    border-right: 4px solid white;
+    border-left: 4px solid white;
+}
+
+.control-header span:not(:first-child) {
+    border-left: none;
+}
+
+.control-secondary {
+    background-color: var(--pdp-light-blue);
+    color: var(--pdp-white);
+    font-family: monospace;
+    font-size: 18px;
+    font-style: italic;
+    text-align: center;
+    padding: 4px 4px;
+    margin-left: 0;
+    margin-right: 0;
+}
+
+.control-buttons {
+    text-align: right;
+}
+
+/* registers */
+
+table.register-table {
+    font-family: monospace;
+    width: 100%;
+    padding: 5px;
+    background-color: black;
+    color: white;
+    border-radius: 8px;
+}
+
+table.register-table tr td.align-right {
+    text-align: right;
+    min-width: 100px;
+}
+
+table.register-table tr td.register-lights {
+    padding-left: 20px;
+}
+
+table.register-table tr td.flags {
+    text-align: center;
+}
+
+table.register-table tr td.flags span {
+    margin-left: 8px;
+}
+
+table.register-table tr td.flags span .blinken {
+    margin-left: 4px;
+    top: 2px;
+    position: relative;
+}
+
+.blinken {
+    display: inline-block;
+    margin-right: 2px;
+    height: 6px;
+    width: 6px;
+    border-radius: 6px;
+    padding: 3px;
+    background-color: red;
+}
+
+.blinken.off {
+    background-color: #5c0119;
+}
+
+.blinken.space {
+    margin-right: 8px;
+}
+
+/* memory */
+
+.memory-panel {
+    background-color: #eee;
+    display: flex;
+    flex-direction: column;
+}
+
+.memory-header {
+    font-family: monospace;
+    font-weight: bold;
+    font-size: 16px;
+    /* overflow: auto; */
+    padding: 4px;
+}
+
+.memory {
+    overflow: auto;
+}
+
+.memory table tr td {
+    font-family: monospace;
+    font-size: 8px;
+}
+
+.current-address {
+    background-color: #78e878;
+}
+
+.code {
+    background-color: darkseagreen;
+}
+
+.data {
+    background-color: lightgoldenrodyellow;
+}
+
+.heap {
+    background-color: lightcoral;
+}
+
+.stack {
+    background-color: lightsalmon;
+}
+
+/* display */
+
+.display {
+    min-height: 480px;
+}
+
+.display-canvas {
+    padding: 24px 64px;
+    width: 320px;
+    height: 288px;
+    image-rendering: pixelated; /* Keeps sharp pixels, no smoothing */
+    image-rendering: -moz-crisp-edges; /* Firefox */
+    image-rendering: crisp-edges; /* Standard */
+}
+/* console */
+
+.console {
+    color: #ffcc00;
+    background-color: #35291c;
+    white-space: pre-wrap;
+    font-family: monospace;
+    font-weight: bold;
+    padding: 5px;
+    overflow: auto;
+}
+
+.console-prompt {
+    margin-right: 6px;
+}
+
+input.console-input {
+    color: #ffcc00;
+    background-color: #35291c;
+    border: none;
+    outline: none;
+    font-weight: bold;
+    font-family: monospace;
+}
+
+.small-button {
+    transform: rotate(-25deg) translateY(20px) translateX(-20px);
+    margin: 2px;
+    width: 50px;
+    background-color: #7e777b;
+    border: 1px solid dimgray;
+    border-radius: 8px;
+    color: whitesmoke;
+    box-shadow: rgb(0, 0, 0, .2) 2px 2px 1px 1px;
+}