3 files changed, 54 insertions, 3 deletions
diff --git a/src/vm/core.js b/src/vm/core.js
index 399cfc6..074e156 100644
--- a/src/vm/core.js
+++ b/src/vm/core.js
@@ -11,8 +11,8 @@ class Core {
 		for (let i=0; i<size; i++) {
 			this.data[i] = {
 				opcode: Op.DAT,
-				a: { value: 0, mode: AddrMode.Direct },
-				b: { value: 0, mode: AddrMode.Direct },
+				a: { value: 0, mode: AddrMode.Immediate },
+				b: { value: 0, mode: AddrMode.Immediate },
 			};
 		}
 	}
diff --git a/src/vm/instruction.js b/src/vm/instruction.js
index ac4cd83..c991643 100644
--- a/src/vm/instruction.js
+++ b/src/vm/instruction.js
@@ -7,3 +7,18 @@ exports.DAT = function(core, pc, ins) {
 	// do nothing and die
 	return [];
 }
+
+
+exports.MOV = function(core, pc, ins) {
+	if (ins.a.mode === AddrMode.Immediate) {
+		const dst = core.getValue(pc, ins.b);
+		dst.b.value = ins.a.value;
+	} else {
+		const src = core.getValue(pc, ins.a);
+		const dstLocation = core.getLocation(pc, ins.b);
+		// hacky deep copy
+		core.data[dstLocation] = JSON.parse(JSON.stringify(src));
+	}
+
+	return [pc + 1];
+}
diff --git a/src/vm/instruction.test.js b/src/vm/instruction.test.js
index 5dc7eea..3535b76 100644
--- a/src/vm/instruction.test.js
+++ b/src/vm/instruction.test.js
@@ -1,7 +1,7 @@
 'use strict';
 
 const { Core } = require('./core.js');
-const { DAT } = require('./instruction.js');
+const { DAT, MOV } = require('./instruction.js');
 
 
 const CORESIZE = 8000;
@@ -13,3 +13,39 @@ test('DAT does nothing and kills the program', () => {
 	const ins = core.data[pc];
 	expect(DAT(core, pc, ins)).toEqual([]);
 });
+
+
+test('MOV correctly moves a full instruction', () => {
+	const core = new Core(CORESIZE);
+	const pc = 20;
+	core.data[pc] = {
+		opcode: 'MOV',
+		a: { mode: 'direct', value: 0 },
+		b: { mode: 'direct', value: 1 },
+	};
+	const ins = core.data[pc];
+	expect(core.data[pc+1].opcode).toBe('DAT');
+	expect(MOV(core, pc, ins)).toEqual([pc+1]);
+	expect(core.data[pc]).toEqual(core.data[pc+1]);
+	expect(core.data[pc+1].opcode).toBe('MOV');
+});
+
+
+test('MOV correctly moves a B-field', () => {
+	const core = new Core(CORESIZE);
+	const pc = 20;
+	core.data[pc] = {
+		opcode: 'MOV',
+		a: { mode: 'immediate', value: 100 },
+		b: { mode: 'direct', value: 1 },
+	};
+	const ins = core.data[pc];
+	expect(core.data[pc+1].opcode).toBe('DAT');
+	expect(MOV(core, pc, ins)).toEqual([pc+1]);
+	expect(core.data[pc+1]).toEqual({	
+		opcode: 'DAT',
+		a: { mode: 'immediate', value: 0 },
+		b: { mode: 'immediate', value: 100 },
+	});
+
+});