Initial commit

2023-08-28 14:00:07 +02:00
commit 35736a5fd2
23 changed files with 1035 additions and 0 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -0,0 +1,42 @@
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
--- a/.idea/.gitignore
+++ b/.idea/.gitignore
@@ -0,0 +1,6 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml
--- a/.idea/codeStyles/Project.xml
+++ b/.idea/codeStyles/Project.xml
@@ -0,0 +1,10 @@
+<component name="ProjectCodeStyleConfiguration">
+  <code_scheme name="Project" version="173">
+    <JetCodeStyleSettings>
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+    </JetCodeStyleSettings>
+    <codeStyleSettings language="kotlin">
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+    </codeStyleSettings>
+  </code_scheme>
+</component>
--- a/.idea/codeStyles/codeStyleConfig.xml
+++ b/.idea/codeStyles/codeStyleConfig.xml
@@ -0,0 +1,5 @@
+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="USE_PER_PROJECT_SETTINGS" value="true" />
+  </state>
+</component>
--- a/.idea/encodings.xml
+++ b/.idea/encodings.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Encoding">
+    <file url="PROJECT" charset="UTF-8" />
+  </component>
+</project>
--- a/.idea/gradle.xml
+++ b/.idea/gradle.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="GradleSettings">
+    <option name="linkedExternalProjectsSettings">
+      <GradleProjectSettings>
+        <option name="externalProjectPath" value="$PROJECT_DIR$" />
+        <option name="modules">
+          <set>
+            <option value="$PROJECT_DIR$" />
+          </set>
+        </option>
+      </GradleProjectSettings>
+    </option>
+  </component>
+</project>
--- a/.idea/inspectionProfiles/Project_Default.xml
+++ b/.idea/inspectionProfiles/Project_Default.xml
@@ -0,0 +1,6 @@
+<component name="InspectionProjectProfileManager">
+  <profile version="1.0">
+    <option name="myName" value="Project Default" />
+    <inspection_tool class="ReplaceUntilWithRangeUntil" enabled="true" level="WEAK WARNING" enabled_by_default="true" />
+  </profile>
+</component>
--- a/.idea/kotlinc.xml
+++ b/.idea/kotlinc.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="KotlinJpsPluginSettings">
+    <option name="version" value="1.9.0" />
+  </component>
+</project>
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CheckStyle-IDEA">
+    <option name="configuration">
+      <map>
+        <entry key="checkstyle-version" value="8.18" />
+        <entry key="copy-libs" value="false" />
+        <entry key="location-0" value="BUNDLED:(bundled):Sun Checks" />
+        <entry key="location-1" value="BUNDLED:(bundled):Google Checks" />
+        <entry key="scan-before-checkin" value="false" />
+        <entry key="scanscope" value="JavaOnly" />
+        <entry key="suppress-errors" value="false" />
+      </map>
+    </option>
+  </component>
+  <component name="EmacsSettings">
+    <option name="emacsPath" value="/usr/bin/emacs" />
+  </component>
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
+  <component name="FrameworkDetectionExcludesConfiguration">
+    <file type="web" url="file://$PROJECT_DIR$" />
+  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" project-jdk-name="19" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -0,0 +1,27 @@
+plugins {
+    kotlin("jvm") version "1.9.0"
+    application
+}
+
+group = "com.thequux"
+version = "1.0-SNAPSHOT"
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation(kotlin("test"))
+}
+
+tasks.test {
+    useJUnitPlatform()
+}
+
+kotlin {
+    jvmToolchain(8)
+}
+
+application {
+    mainClass.set("MainKt")
+}
--- a/doc/opcode_map.txt
+++ b/doc/opcode_map.txt
@@ -0,0 +1,84 @@
+# vim:ts=14
+opcode	mnemonic
+005500/10	ADC
+105500/10	ADCB
+060000/4	ADD
+072000/7	ASH
+073000/7	ASHC
+006300/10	ASL
+106300/10	ASLB
+006200/10	ASR
+106200/10	ASRB
+103000/8	BCC
+103400/8	BCS
+001400/8	BEQ
+002000/8	BGE
+003000/8	BGT
+101000/8	BHI
+103000/8	BHIS
+040000/4	BIC
+140000/4	BICB
+050000/4	BIS
+150000/4	BISB
+030000/4	BIT
+130000/4	BITB
+003400/8	BLE
+103400/8	BLO
+101400/8	BLOS
+002400/8	BLT
+100400/8	BMI
+001000/8	BNE
+100000/8	BPL
+000003/16	BPT
+000400/8	BR
+102000/10	BVC	?
+102400/8	BVS
+005000/10	CLR
+105000/10	CLRB
+000240/12	C
+020000/4	CMP
+120000/4	CMPB
+005100/10	COM
+105100/10	COMB
+007000/10	CSM
+005300/10	DEC
+105300/10	DECB
+071000/7	DIV
+104000/8	EMT
+000000/16	HALT
+005200/10	INC
+105200/10	INCB
+000004/16	IOT
+000100/10	JMP
+004000/7	JSR
+170003/16	LDUB	maint
+006400/10	MARK
+076600/16	MED	maint
+106500/10	MFPD
+006500/10	MFPI
+106700/10	MFPS
+000007/16	MFPT
+170004/16	MNS	maint
+010000/4	MOV
+110000/4	MOVB
+170005/16	MPP	maint
+106600/10	MTPD
+006600/10	MTPI
+106400/10	MTPS
+070000/7	MUL
+005400/10	NEG
+105400/10	NEGB
+000005/16	RESET
+006100/10	ROL
+106100/10	ROLB
+006000/10	ROR
+006100/10	RORB
+000002/16	RTI
+000200/13	RTS
+000006/16	RTT
+005600/10	SBC
+105600/10	SBCB
+000260/12	S
+077000/7	sob
+000230/13	SPL
+
--- a/gradle.properties
+++ b/gradle.properties
@@ -0,0 +1 @@
+kotlin.code.style=official
--- a/gradle/wrapper/gradle-wrapper.jar
+++ b/gradle/wrapper/gradle-wrapper.jar
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.2-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
--- a/234
+++ b/234
@@ -0,0 +1,234 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -0,0 +1,12 @@
+pluginManagement {
+    repositories {
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+plugins {
+    id("org.gradle.toolchains.foojay-resolver-convention") version "0.5.0"
+}
+
+rootProject.name = "mc-pdp"
--- a/src/main/kotlin/Main.kt
+++ b/src/main/kotlin/Main.kt
@@ -0,0 +1,7 @@
+fun main(args: Array<String>) {
+    println("Hello World!")
+
+    // Try adding program arguments via Run/Debug configuration.
+    // Learn more about running applications: https://www.jetbrains.com/help/idea/running-applications.html.
+    println("Program arguments: ${args.joinToString()}")
+}
--- a/src/main/kotlin/com/thequux/mcpdp/core/AddressSpace.kt
+++ b/src/main/kotlin/com/thequux/mcpdp/core/AddressSpace.kt
@@ -0,0 +1,8 @@
+package com.thequux.mcpdp.core
+
+interface AddressSpace {
+    fun getw(addr: UShort): UShort
+    fun getb(addr: UShort): UByte
+    fun setw(addr: UShort, value: UShort)
+    fun setb(addr: UShort, value: UByte)
+}
--- a/src/main/kotlin/com/thequux/mcpdp/core/CPU.kt
+++ b/src/main/kotlin/com/thequux/mcpdp/core/CPU.kt
@@ -0,0 +1,349 @@
+package com.thequux.mcpdp.core
+
+import com.thequux.mcpdp.ext.bit.*
+
+/// The main CPU
+///
+/// By default, the memory map is arranged as follows:
+/// Fxxx: Channel I/O
+/// Exxx: ROM
+/// xxxx: rest
+@OptIn(ExperimentalUnsignedTypes::class)
+class CPU(private val core: AddressSpace) {
+    private val registers = UShortArray(8)
+    public var psw: UShort = 0U
+    private var pc: UShort
+        get() = registers[7]
+        set(value) {
+            registers[7] = value
+        }
+
+    private var cc: UShort
+        get() = psw and 0xFu
+        set(value) {
+            psw = (psw and 0xFFFu) or (value and 0xFu)
+        }
+
+    private var N: Boolean = false
+    private var C: Boolean = false
+    private var Z: Boolean = false
+    private var V: Boolean = false
+
+    /// Load an operand. This performs any indicated pre-inc/post-dec, so this or op_adjust must be called exactly once per operand
+    private fun op_resolve(operand: Int, byte_mode: Boolean = false): UInt {
+        val mode = operand shr 3
+        val reg = operand and 0x7
+        val increment = if (byte_mode && reg != 7) 1U else 2U
+        return when (mode) {
+            0 -> reg.toUInt() + 0x1_0000U
+            1 -> registers[reg].toUInt()
+            2 -> {
+                val addr = registers[reg]
+                registers[reg] = (addr + increment).toUShort()
+                addr.toUInt()
+            }
+            3 -> {
+                val addr = registers[reg]
+                registers[reg] = (addr + 2U).toUShort()
+                core.getw(addr).toUInt()
+            }
+            4 -> {
+                registers[reg] = (registers[reg] - increment).toUShort()
+                return registers[reg].toUInt()
+            }
+            5 -> {
+                registers[reg] = (registers[reg] - 2U).toUShort()
+                core.getw(registers[reg]).toUInt()
+            }
+            6 -> {
+                val idx = core.getw(pc)
+                pc = (pc + 2u).toUShort()
+                idx + registers[reg]
+            }
+            7 -> {
+                val idx = core.getw(pc)
+                pc = (pc+2u).toUShort()
+                core.getw((idx+registers[reg]).toUShort()).toUInt()
+            }
+            else -> throw InvalidOpcodeException()
+        }
+    }
+
+    /// Store an operand. This assumes that the spec has already been `load`ed or `adjust`ed
+    private fun op_storb(spec: UInt, value: UByte) {
+        val addr = (spec and 0xFFFFu).toUShort()
+        if (spec >= 0x1_0000u) {
+            // register
+            registers[addr.toInt()] = registers[addr.toInt()] and 0xFF00u or value.toUShort()
+        } else {
+            core.setb(addr, value)
+        }
+    }
+
+    private fun op_loadb(spec: UInt): UByte {
+        val addr = (spec and 0xFFFFu).toUShort()
+        return if (spec > 0x1_0000u) {
+            (registers[addr.toInt()] and 0xFFu).toUByte()
+        } else {
+            core.getb(addr)
+        }
+    }
+
+    private fun op_storw(spec: UInt, value: UShort) {
+        val addr = (spec and 0xFFFFu).toUShort()
+        if (spec >= 0x1_0000u) {
+            // register
+            registers[addr.toInt()] = value
+        } else {
+            core.setw(addr, value)
+        }
+    }
+
+    private fun op_loadw(spec: UInt): UShort {
+        val addr = (spec and 0xFFFFu).toUShort()
+        return if (spec > 0x1_0000u) {
+            (registers[addr.toInt()] and 0xFFu)
+        } else {
+            core.getw(addr)
+        }
+    }
+
+    companion object {
+        val CC_C: UShort = 1U
+        val CC_V: UShort = 2U
+        val CC_Z: UShort = 4U
+        val CC_N: UShort = 8U
+    }
+    private fun opc_dst(opcode: Int): UInt = op_resolve(opcode and 0x3F)
+    private fun opc_src(opcode: Int): UInt = op_resolve(opcode shr 6 and 0xFC0)
+
+    private fun br_rel(cond: Boolean, opcode: Int) {
+        if (cond) {
+            pc = (pc + 2u * (opcode and 0xFF).toByte().toShort().toUShort()).toUShort()
+        }
+    }
+    fun step() {
+        val opcode = core.getw(pc).toInt()
+        pc = (pc + 2u).toUShort()
+        when (opcode and 0xF000) {
+            0x0, 0x8000 -> when (opcode and 0xFFC0) {
+                0x0000 -> when (opcode) {
+                    0x0003 -> throw Trap(14) // BPT
+                }
+                0x0080 ->
+                0x0100, 0x0140, 0x0180, 0x01C0 -> br_rel(true, opcode) // BR
+                0x0200, 0x0240, 0x0280, 0x02C0 -> br_rel(!Z, opcode) // BNE
+                0x0300, 0x0340, 0x0380, 0x03C0 -> br_rel(Z, opcode) // BEQ
+                0x0400, 0x0440, 0x0480, 0x04C0 -> br_rel(N == V, opcode) // BGE
+                0x0600, 0x0640, 0x0680, 0x06C0 -> br_rel(!Z and (N == V), opcode) // BGT
+                0x0500, 0x0540, 0x0580, 0x05C0 -> br_rel(N xor V, opcode) // BLT
+                0x0700, 0x0740, 0x0780, 0x07C0 -> br_rel(Z or (N xor V), opcode) // BLE
+
+                0x0A00 -> { // CLR
+                    op_storw(opc_dst(opcode), 0U)
+                    N = false
+                    V = false
+                    C = false
+                    Z = true
+                } // CLR
+                0x0B40 -> { // ADC
+                    val dst = opc_dst(opcode)
+                    val c: UShort = if (C) 1u else 0u
+                    val res = (op_loadw(dst) + c).toUShort()
+                    op_storw(dst, res)
+                    N = res bit 15
+                    Z = res == 0u.toUShort()
+                    V = (res == 0x8000u.toUShort()) and C
+                    C = Z and C
+                } // ADC
+                0x0C80 -> { // ASR
+                    val dst = opc_dst(opcode)
+                    val src = op_loadw(dst).toShort()
+                    val res = (src shr 1).toUShort()
+                    op_storw(dst, res)
+                    N = res bit 15
+                    Z = res == 0.toUShort()
+                    C = src bit 0
+                    V = N xor C
+                } // ASR
+                0x0CC0 -> { // ASL
+                    val dst = opc_dst(opcode)
+                    val src = op_loadw(dst)
+                    val res = src shl 1
+                    op_storw(dst, res.toUShort())
+                    N = res bit 15
+                    Z = res == 0.toUShort()
+                    C = src and 0x8000u != 0u.toUShort()
+                    V = N xor C
+                } // ASL
+                0x8000, 0x8040, 0x8080, 0x80C0 -> br_rel(!N, opcode) // BPL
+                0x8100, 0x8140, 0x8180, 0x81C0 -> br_rel(N, opcode) // BMI
+                0x8200, 0x8240, 0x8280, 0x82C0 -> br_rel(!C and !Z, opcode) // BHI
+                0x8300, 0x8340, 0x8380, 0x83C0 -> br_rel(C or Z, opcode) // BLOS
+                0x8400, 0x8440, 0x8480, 0x84C0 -> br_rel(!V, opcode) // BVC
+                0x8500, 0x8540, 0x8580, 0x85C0 -> br_rel(V, opcode) // BVS
+                0x8600, 0x8640, 0x8680, 0x86C0 -> br_rel(!C, opcode) // BCC/BHIS
+                0x8700, 0x8740, 0x8780, 0x87C0 -> br_rel(C, opcode) // BCS/BLO
+
+                0x8A00 -> { // CLRB
+                    op_storb(opc_dst(opcode), 0U)
+                    N = false
+                    V = false
+                    C = false
+                    Z = true
+                } // CLRB
+                0x8B40 -> { // ADCB
+                    val dst = opc_dst(opcode)
+                    val c: UShort = if (C) 1u else 0u
+                    val res = (op_loadb(dst) + c).toUByte()
+                    op_storb(dst, res)
+                    N = res bit 7
+                    Z = res == 0u.toUByte()
+                    V = (res == 0x80u.toUByte()) and C
+                    C = Z and C
+                } // ADCB
+                0x8C80 -> { // ASRB
+                    val dst = opc_dst(opcode)
+                    val src = op_loadb(dst).toByte()
+                    val res = (src shr 1).toUByte()
+                    op_storb(dst, res)
+                    N = res bit 7
+                    Z = res == 0.toUByte()
+                    C = src bit 0
+                    V = N xor C
+                } // ASRB
+                0x8CC0 -> { // ASLB
+                    val dst = opc_dst(opcode)
+                    val src = op_loadb(dst)
+                    val res = (src shl 1).toUByte()
+                    op_storw(dst, res.toUShort())
+                    N = res bit 7
+                    Z = res == 0.toUByte()
+                    C = src bit 7
+                    V = N xor C
+                } // ASLB
+            }
+            0x3000 -> { // BIT
+                val src = opc_src(opcode)
+                val dst = opc_dst(opcode)
+                val res = op_loadw(dst) and op_loadw(src).inv()
+                N = res bit 15
+                Z = res != 0u.toUShort()
+                V = false
+            } // BIT
+            0x4000 -> { // BIC
+                val src = opc_src(opcode)
+                val dst = opc_dst(opcode)
+                val res = op_loadw(dst) and op_loadw(src).inv()
+                op_storw(dst, res)
+                N = res bit 15
+                Z = res != 0u.toUShort()
+                V = false
+            } // BIC
+            0x5000 -> { // BIS
+                val src = opc_src(opcode)
+                val dst = opc_dst(opcode)
+                val res = op_loadw(dst) or op_loadw(src)
+                op_storw(dst, res)
+                N = res and 0x8000u != 0u.toUShort()
+                Z = res != 0u.toUShort()
+                V = false
+            } // BIS
+            0x6000 -> { // ADD
+                val src = opc_src(opcode)
+                val dst = opc_dst(opcode)
+                val srcv = op_loadw(src)
+                val dstv = op_loadw(dst)
+                val res = (srcv + dstv)
+                val resw = res.toUShort()
+                op_storw(dst, res.toUShort())
+                N = resw > 0x7FFFu
+                Z = resw == 0.toUShort()
+                val src_sign = srcv and 0x8000u
+                V = (src_sign == dstv and 0x8000u) && (src_sign != resw and 0x8000u)
+                C = (resw >= 0x10000u)
+            } // ADD
+            7000 -> when (opcode shr 9 and 0x7) {
+                2 -> { // ASH
+                    val r = opcode shr 6 and 0x7
+                    var count = (op_loadb(opc_src(opcode)) and 0x3Fu).toInt()
+                    val src = registers[r].toShort().toInt() // two casts to sign extend
+                    count = count sex 6
+                    V = false
+                    val res = if (count > 0) {
+                        C = (src shl (count-1)) bit 15
+                        val shifted = if (count < 16) {
+                            src shr 16-count
+                        } else {
+                            src
+                        }
+                        V = (shifted != 0) and (shifted != -1)
+                        src shl count
+                    } else if (count < 0) {
+                        count = -count
+                        C = (src shr (count-1)) bit 0
+                        src shr count
+                    } else {
+                        C = false
+                        src
+                    }
+                    registers[r] = res.toUShort()
+                    N = res < 0
+                    Z = res == 0
+                } // ASH
+                3 -> { // ASHC
+                    val r = opcode shr 6 and 0x7
+                    var count = (op_loadb(opc_src(opcode)) and 0x3Fu).toInt() sex 6
+                    val src = (registers[r].toUInt() shl 16 or registers[r or 1].toUInt()).toInt() // two casts to sign extend
+                    V = false
+                    val res = if (count > 0) {
+                        C = (src shl (count-1)) bit 31
+                        val shifted = src shr 32-count
+                        V = (shifted != 0) and (shifted != -1)
+                        src shl count
+                    } else if (count < 0) {
+                        count = -count
+                        C = (src shr (count-1)) bit 0
+                        src shr count
+                    } else {
+                        C = false
+                        src
+                    }
+                    val resS = res.toUShort()
+                    registers[r] = (res and 0xFFFF).toUShort()
+                    registers[r or 1] = (res shr 16 and 0xFFFF).toUShort()
+                    N = res < 0
+                    Z = res == 0
+                } // ASHC
+
+            }
+            0xB000 -> { // BITB
+                val src = opc_src(opcode)
+                val dst = opc_dst(opcode)
+                val res = op_loadb(dst) and op_loadb(src).inv()
+                N = res bit 7
+                Z = res != 0u.toUByte()
+                V = false
+            } // BITB
+            0xC000 -> { // BICB
+                val src = opc_src(opcode)
+                val dst = opc_dst(opcode)
+                val res = op_loadb(dst) and op_loadb(src).inv()
+                op_storb(dst, res)
+                N = res bit 7
+                Z = res != 0u.toUByte()
+                V = false
+            } // BICB
+            0xD000 -> { // BISB
+                val src = opc_src(opcode)
+                val dst = opc_dst(opcode)
+                val res = op_loadb(dst) or op_loadb(src)
+                op_storb(dst, res)
+                N = res bit 7
+                Z = res != 0u.toUByte()
+                V = false
+            } // BISB
+
+        }
+    }
+}
--- a/src/main/kotlin/com/thequux/mcpdp/core/InvalidOpcodeException.kt
+++ b/src/main/kotlin/com/thequux/mcpdp/core/InvalidOpcodeException.kt
@@ -0,0 +1,9 @@
+package com.thequux.mcpdp.core
+
+class InvalidOpcodeException : Exception {
+
+    constructor() : super()
+    constructor(message: String?) : super(message)
+    constructor(message: String?, cause: Throwable?) : super(message, cause)
+    constructor(cause: Throwable?) : super(cause)
+}
--- a/src/main/kotlin/com/thequux/mcpdp/core/Trap.kt
+++ b/src/main/kotlin/com/thequux/mcpdp/core/Trap.kt
@@ -0,0 +1,5 @@
+package com.thequux.mcpdp.core
+
+class Trap(val vector: Int): Exception("TRAP#$vector") {
+
+}
--- a/src/main/kotlin/com/thequux/mcpdp/ext/bit/bitext.kt
+++ b/src/main/kotlin/com/thequux/mcpdp/ext/bit/bitext.kt
@@ -0,0 +1,83 @@
+package com.thequux.mcpdp.ext.bit
+
+import kotlin.experimental.and
+import kotlin.math.max
+
+infix fun Byte.shr(qty: Int): Byte = this.toInt().shr(max(qty, 7)).toByte()
+infix fun Byte.shl(qty: Int): Byte = if (qty > 7) 0 else this.toInt().shl(qty).toByte()
+infix fun Byte.bit(n: Int): Boolean = this.toInt() shr n and 1 != 0
+fun Byte.bit(n: Int, v: Boolean): Byte = if (v) this bis n else this bic n
+infix fun Byte.bis(n: Int): Byte = this.toInt().or(1 shl n).toByte()
+infix fun Byte.bic(n: Int): Byte = this.toInt().and(1.shl(n).inv()).toByte()
+infix fun Byte.sex(n: Int): Byte {
+    val sign = 1.toByte() shl n+1
+    return ((this and sign.dec()) - (this and sign)).toByte()
+}
+
+infix fun UByte.shr(qty: Int): UByte = this.toUInt().shr(max(qty, 7)).toUByte()
+infix fun UByte.shl(qty: Int): UByte = if (qty > 7) 0U else this.toInt().shl(qty).toUByte()
+infix fun UByte.bit(n: Int): Boolean = this.toUInt() shr n and 1U != 0U
+fun UByte.bit(n: Int, v: Boolean): UByte = if (v) this bis n else this bic n
+infix fun UByte.bis(n: Int): UByte = this.toUInt().or(1U shl n).toUByte()
+infix fun UByte.bic(n: Int): UByte = this.toUInt().and(1U.shl(n).inv()).toUByte()
+infix fun UByte.sex(n: Int): UByte {
+    val sign = 1.toUByte() shl n+1
+    return ((this and sign.dec()) - (this and sign)).toUByte()
+}
+
+infix fun Short.shr(qty: Int): Short = this.toInt().shr(max(qty, 15)).toShort()
+infix fun Short.shl(qty: Int): Short = if (qty > 15) 0 else this.toInt().shl(qty).toShort()
+infix fun Short.bit(n: Int): Boolean = this.toInt() shr n and 1 != 0
+fun Short.bit(n: Int, v: Boolean): Short = if (v) this bis n else this bic n
+infix fun Short.bis(n: Int): Short = this.toInt().or(1 shl n).toShort()
+infix fun Short.bic(n: Int): Short = this.toInt().and(1.shl(n).inv()).toShort()
+infix fun Short.sex(n: Int): Short {
+    val sign = 1.toShort() shl n+1
+    return ((this and sign.dec()) - (this and sign)).toShort()
+}
+
+infix fun UShort.shr(qty: Int): UShort = this.toUInt().shr(max(qty, 15)).toUShort()
+infix fun UShort.shl(qty: Int): UShort = if (qty > 15) 0U else this.toInt().shl(qty).toUShort()
+infix fun UShort.bit(n: Int): Boolean = this.toUInt() shr n and 1U != 0U
+fun UShort.bit(n: Int, v: Boolean): UShort = if (v) this bis n else this bic n
+infix fun UShort.bis(n: Int): UShort = this.toUInt().or(1U shl n).toUShort()
+infix fun UShort.bic(n: Int): UShort = this.toUInt().and(1U.shl(n).inv()).toUShort()
+infix fun UShort.sex(n: Int): UShort {
+    val sign = 1.toUShort() shl n+1
+    return ((this and sign.dec()) - (this and sign)).toUShort()
+}
+
+infix fun Int.bit(n: Int): Boolean = this shr n and 1 != 0
+fun Int.bit(n: Int, v: Boolean): Int = if (v) this bis n else this bic n
+infix fun Int.bis(n: Int): Int = this.or(1 shl n)
+infix fun Int.bic(n: Int): Int = this and (1 shl n).inv()
+infix fun Int.sex(n: Int): Int {
+    val sign = 1 shl n+1
+    return ((this and sign.dec()) - (this and sign))
+}
+infix fun UInt.bit(n: Int): Boolean = this shr n and 1U != 0U
+fun UInt.bit(n: Int, v: Boolean): UInt = if (v) this bis n else this bic n
+infix fun UInt.bis(n: Int): UInt = this.or(1U shl n)
+infix fun UInt.bic(n: Int): UInt = this.and(1U.shl(n).inv())
+infix fun UInt.sex(n: Int): UInt {
+    val sign = 1U shl n+1
+    return ((this and sign.dec()) - (this and sign))
+}
+
+infix fun Long.bit(n: Int): Boolean = this shr n and 1L != 0L
+fun Long.bit(n: Int, v: Boolean): Long = if (v) this bis n else this bic n
+infix fun Long.bis(n: Int): Long = this.or(1L shl n)
+infix fun Long.bic(n: Int): Long = this and (1L shl n).inv()
+infix fun Long.sex(n: Int): Long {
+    val sign = 1.toLong() shl n+1
+    return (this and sign.dec()) - (this and sign)
+}
+infix fun ULong.bit(n: Int): Boolean = this shr n and 1UL != 0UL
+fun ULong.bit(n: Int, v: Boolean): ULong = if (v) this bis n else this bic n
+infix fun ULong.bis(n: Int): ULong = this.or(1UL shl n)
+infix fun ULong.bic(n: Int): ULong = this.and(1UL.shl(n).inv())
+infix fun ULong.sex(n: Int): ULong {
+    val sign = 1UL shl n+1
+    return ((this and (sign.dec())) - (this and sign))
+}
+