ignored empty lines and implemented END

system/assembler.ts

@@ -1,5 +1,5 @@
 import { instructionSet, syntax } from "./cpu/arch.js";
-import { getDataByAddress, getDataByVariable } from "./memory/data.js";
+import { getDataByVariable } from "./memory/data.js";
 import { getSourceCode } from "./editor.js";
 import { Instruction } from "./cpu/interface.js";
 
@@ -9,6 +9,9 @@ const OPCODE_LENGTH = 4;
 const PARAM_LENGTH = 11;
 
 function parseInstruction(text: string) {
+  if (!text) {
+    return null;
+  }
   let mnemonic = text.split(" ")[0].toUpperCase();
   const operation = instructionSet[mnemonic];
   if (!operation) {
@@ -52,6 +55,9 @@ function parseInstruction(text: string) {
 
 function encodeInstruction(content: string) {
   const ins = parseInstruction(content);
+  if (!ins) {
+    return "";
+  }
   const code = ins.code.toString(2).padStart(OPCODE_LENGTH, "0");
   const addressMode = ins.addressingMode.toString(2);
   const operand = ins.operand.toString(2).padStart(PARAM_LENGTH, "0");
@@ -86,10 +92,10 @@ function decodeText(binaryInstruction: string) {
 
 function makeObjectCode() {
   const objCode: string[] = [];
-
-  for (const line of getSourceCode()) {
-    if (!line) {
-      objCode.push("");
+  const sourceCode = getSourceCode();
+  for (const [index, line] of sourceCode.entries()) {
+    if (index == sourceCode.length - 1 && !line.toLowerCase().includes("end")) {
+      throw new SyntaxError('Missing "END" instruction.');
     }
     const objSrc = encodeInstruction(line);
     objCode.push(objSrc);

system/cpu/arch.ts

@@ -1,6 +1,7 @@
 import { Push, Pop } from "../instructions/stack.js";
 import { Add, Sub, Mul, Div } from "../instructions/arithmetic.js";
 import { Executable } from "./interface.js";
+import { End } from "../instructions/process.js";
 
 const syntax: { [key: string]: RegExp } = {
   addressable: /\s*([a-zA-Z]+)\s+(\d+)\s*/,
@@ -41,10 +42,10 @@ const instructionSet: {
     type: "op",
     executor: new Div(),
   },
-  HALT: {
+  END: {
     code: 6,
     type: "op",
-    executor: null,
+    executor: new End(),
   },
   IN: {
     code: 7,

system/cpu/execution_unit.ts

@@ -10,15 +10,19 @@ function fetch(): Instruction | null {
   const counter = cpu.programCounter.parseHex();
 
   if (counter == processInfo.objectCode.length) {
+    processInfo.endSignal = true;
     return null;
   }
 
   const nextCounterHex = (counter + 1).asHex16();
-  cpu.aluFlags = "Z=0,Of=0";
+  cpu.aluFlags = "Z=0,O=0";
   cpu.controlUnit = "PCout,MARin,ClrY,SetCin,ADD,Zin";
   cpu.programCounter = cpu.aluZ = nextCounterHex;
 
   const binInstruction = processInfo.objectCode[counter];
+  if (!binInstruction) {
+    return null;
+  }
   const hexInstruction = binInstruction.parseBin().asHex16();
   cpu.instructionRegister = cpu.MDR = hexInstruction;
 
@@ -58,6 +62,7 @@ function resetRegisters(): void {
 
   resetSpOffset();
   clearStackData();
+  processInfo.endSignal = false;
 }
 
 function execute(instruction: Instruction): void {

system/events.ts

@@ -6,12 +6,10 @@ function run() {
   try {
     resetRegisters();
     processInfo.objectCode = makeObjectCode();
-    while (true) {
+    while (!processInfo.endSignal) {
       const ins = fetch();
       if (ins) {
         execute(ins);
-      } else {
-        break;
       }
     }
   } catch (e: any) {

system/instructions/arithmetic.ts

@@ -8,7 +8,7 @@ function performOp(operation: (x: number, y: number) => number) {
   const topOfStackAddress = cpu.stackPointer.parseHex();
   if (topOfStackAddress == 0) {
     throw new ReferenceError(
-      "There is not enough data in the stack to perform the operation."
+      "There is not enough data in the stack to perform the operation.",
     );
   }
 
@@ -24,7 +24,7 @@ function performOp(operation: (x: number, y: number) => number) {
   cpu.aluFlags = "";
   const result = operation(+nextOfStack.value, +topOfStack.value);
   cpu.aluFlags += `Z=${+(result == 0)}`;
-  cpu.aluFlags += `, O=${+(result > MAX_WORD_VALUE)}`;
+  cpu.aluFlags += `,O=${+(result > MAX_WORD_VALUE)}`;
 
   cpu.stackPointer = nextOfStackAddress;
   nextOfStack.value = result.toString();

system/instructions/process.ts

@@ -0,0 +1,8 @@
+import { Instruction, Executable } from "../cpu/interface.js";
+import { processInfo } from "../memory/data.js";
+
+export class End implements Executable {
+  run(_: Instruction) {
+    processInfo.endSignal = true;
+  }
+}

system/memory/data.ts

@@ -3,6 +3,7 @@ const VAR_COLUMN = 1;
 
 class ProcessInfo {
   objectCode: string[] = [];
+  endSignal: boolean = false;
 }
 
 var processInfo = new ProcessInfo();