diff --git a/src/Buffer.test.ts b/src/Buffer.test.ts
index d866fd56..087d0ae5 100644
--- a/src/Buffer.test.ts
+++ b/src/Buffer.test.ts
@@ -5,10 +5,10 @@
 
 import { assert, expect } from 'chai';
 import { ITerminal } from './Types';
-import { Buffer, DEFAULT_ATTR_DATA } from './Buffer';
+import { Buffer } from './Buffer';
 import { CircularList } from './common/CircularList';
 import { MockTerminal, TestTerminal } from './TestUtils.test';
-import { BufferLine, CellData } from './BufferLine';
+import { BufferLine, CellData, DEFAULT_ATTR_DATA } from './core/buffer/BufferLine';
 
 const INIT_COLS = 80;
 const INIT_ROWS = 24;
diff --git a/src/Buffer.ts b/src/Buffer.ts
index c1c08c85..14bf53aa 100644
--- a/src/Buffer.ts
+++ b/src/Buffer.ts
@@ -4,42 +4,16 @@
  */
 
 import { CircularList, IInsertEvent } from './common/CircularList';
-import { ITerminal, IBuffer, IBufferLine, BufferIndex, IBufferStringIterator, IBufferStringIteratorResult, ICellData, IAttributeData } from './Types';
+import { ITerminal, IBuffer, BufferIndex, IBufferStringIterator, IBufferStringIteratorResult } from './Types';
+import { IBufferLine, ICellData, IAttributeData } from './core/Types';
 import { IMarker } from 'xterm';
-import { BufferLine, CellData, AttributeData } from './BufferLine';
+import { BufferLine, CellData, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE, WHITESPACE_CELL_CHAR, WHITESPACE_CELL_WIDTH, WHITESPACE_CELL_CODE, CHAR_DATA_WIDTH_INDEX, CHAR_DATA_CHAR_INDEX, DEFAULT_ATTR_DATA } from './core/buffer/BufferLine';
 import { reflowLargerApplyNewLayout, reflowLargerCreateNewLayout, reflowLargerGetLinesToRemove, reflowSmallerGetNewLineLengths, getWrappedLineTrimmedLength } from './BufferReflow';
-import { DEFAULT_COLOR } from './renderer/atlas/Types';
 import { EventEmitter2, IEvent } from './common/EventEmitter2';
 import { Disposable } from '../lib/common/Lifecycle';
 
-export const DEFAULT_ATTR = (0 << 18) | (DEFAULT_COLOR << 9) | (256 << 0);
-
-export const DEFAULT_ATTR_DATA = new AttributeData();
-
-export const CHAR_DATA_ATTR_INDEX = 0;
-export const CHAR_DATA_CHAR_INDEX = 1;
-export const CHAR_DATA_WIDTH_INDEX = 2;
-export const CHAR_DATA_CODE_INDEX = 3;
 export const MAX_BUFFER_SIZE = 4294967295; // 2^32 - 1
 
-/**
- * Null cell - a real empty cell (containing nothing).
- * Note that code should always be 0 for a null cell as
- * several test condition of the buffer line rely on this.
- */
-export const NULL_CELL_CHAR = '';
-export const NULL_CELL_WIDTH = 1;
-export const NULL_CELL_CODE = 0;
-
-/**
- * Whitespace cell.
- * This is meant as a replacement for empty cells when needed
- * during rendering lines to preserve correct aligment.
- */
-export const WHITESPACE_CELL_CHAR = ' ';
-export const WHITESPACE_CELL_WIDTH = 1;
-export const WHITESPACE_CELL_CODE = 32;
-
 /**
  * This class represents a terminal buffer (an internal state of the terminal), where the
  * following information is stored (in high-level):
diff --git a/src/BufferReflow.test.ts b/src/BufferReflow.test.ts
index 9c978dc0..91454e2a 100644
--- a/src/BufferReflow.test.ts
+++ b/src/BufferReflow.test.ts
@@ -3,9 +3,8 @@
  * @license MIT
  */
 import { assert } from 'chai';
-import { BufferLine } from './BufferLine';
+import { BufferLine, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE } from './core/buffer/BufferLine';
 import { reflowSmallerGetNewLineLengths } from './BufferReflow';
-import { NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE } from './Buffer';
 
 describe('BufferReflow', () => {
   describe('reflowSmallerGetNewLineLengths', () => {
diff --git a/src/BufferReflow.ts b/src/BufferReflow.ts
index 40e16c74..c1068967 100644
--- a/src/BufferReflow.ts
+++ b/src/BufferReflow.ts
@@ -3,9 +3,9 @@
  * @license MIT
  */
 
-import { BufferLine } from './BufferLine';
+import { BufferLine } from './core/buffer/BufferLine';
 import { CircularList } from './common/CircularList';
-import { IBufferLine, ICellData } from './Types';
+import { IBufferLine, ICellData } from './core/Types';
 
 export interface INewLayoutResult {
   layout: number[];
diff --git a/src/BufferSet.ts b/src/BufferSet.ts
index ba885a0e..f22b92dc 100644
--- a/src/BufferSet.ts
+++ b/src/BufferSet.ts
@@ -3,7 +3,8 @@
  * @license MIT
  */
 
-import { ITerminal, IBufferSet, IAttributeData, IBuffer } from './Types';
+import { ITerminal, IBufferSet, IBuffer } from './Types';
+import { IAttributeData } from './core/Types';
 import { Buffer } from './Buffer';
 import { EventEmitter2, IEvent } from './common/EventEmitter2';
 
diff --git a/src/CharWidth.test.ts b/src/CharWidth.test.ts
index ff6f17ed..17822fa2 100644
--- a/src/CharWidth.test.ts
+++ b/src/CharWidth.test.ts
@@ -7,8 +7,7 @@ import { TestTerminal } from './TestUtils.test';
 import { assert } from 'chai';
 import { getStringCellWidth, wcwidth } from './CharWidth';
 import { IBuffer } from './Types';
-import { CHAR_DATA_WIDTH_INDEX, CHAR_DATA_CHAR_INDEX } from './Buffer';
-import { CellData } from './BufferLine';
+import { CellData, CHAR_DATA_WIDTH_INDEX, CHAR_DATA_CHAR_INDEX } from './core/buffer/BufferLine';
 
 
 describe('getStringCellWidth', function(): void {
diff --git a/src/InputHandler.test.ts b/src/InputHandler.test.ts
index dcd4d1b4..f2e8d93e 100644
--- a/src/InputHandler.test.ts
+++ b/src/InputHandler.test.ts
@@ -6,10 +6,9 @@
 import { assert, expect } from 'chai';
 import { InputHandler } from './InputHandler';
 import { MockInputHandlingTerminal, TestTerminal } from './TestUtils.test';
-import { DEFAULT_ATTR_DATA } from './Buffer';
 import { Terminal } from './Terminal';
-import { IBufferLine } from './Types';
-import { CellData, Attributes, AttributeData } from './BufferLine';
+import { IBufferLine } from './core/Types';
+import { CellData, Attributes, AttributeData, DEFAULT_ATTR_DATA } from './core/buffer/BufferLine';
 
 describe('InputHandler', () => {
   describe('save and restore cursor', () => {
diff --git a/src/InputHandler.ts b/src/InputHandler.ts
index 66d16c04..b5b98dd9 100644
--- a/src/InputHandler.ts
+++ b/src/InputHandler.ts
@@ -7,14 +7,13 @@
 import { IInputHandler, IDcsHandler, IEscapeSequenceParser, IInputHandlingTerminal } from './Types';
 import { C0, C1 } from './common/data/EscapeSequences';
 import { CHARSETS, DEFAULT_CHARSET } from './core/data/Charsets';
-import { NULL_CELL_WIDTH, NULL_CELL_CODE, DEFAULT_ATTR_DATA } from './Buffer';
 import { wcwidth } from './CharWidth';
 import { EscapeSequenceParser } from './EscapeSequenceParser';
 import { IDisposable } from 'xterm';
 import { Disposable } from './common/Lifecycle';
 import { concat } from './common/TypedArrayUtils';
 import { StringToUtf32, stringFromCodePoint, utf32ToString } from './core/input/TextDecoder';
-import { CellData, Attributes, FgFlags, BgFlags, AttributeData } from './BufferLine';
+import { CellData, Attributes, FgFlags, BgFlags, AttributeData, NULL_CELL_WIDTH, NULL_CELL_CODE, DEFAULT_ATTR_DATA } from './core/buffer/BufferLine';
 import { EventEmitter2, IEvent } from './common/EventEmitter2';
 
 /**
diff --git a/src/Linkifier.test.ts b/src/Linkifier.test.ts
index 8f734bac..6a2f0ee9 100644
--- a/src/Linkifier.test.ts
+++ b/src/Linkifier.test.ts
@@ -4,11 +4,12 @@
  */
 
 import { assert } from 'chai';
-import { IMouseZoneManager, IMouseZone, ILinkMatcher, ITerminal, IBufferLine } from './Types';
+import { IMouseZoneManager, IMouseZone, ILinkMatcher, ITerminal } from './Types';
+import { IBufferLine } from './core/Types';
 import { Linkifier } from './Linkifier';
 import { MockBuffer, MockTerminal, TestTerminal } from './TestUtils.test';
 import { CircularList } from './common/CircularList';
-import { BufferLine, CellData } from './BufferLine';
+import { BufferLine, CellData } from './core/buffer/BufferLine';
 
 class TestLinkifier extends Linkifier {
   constructor(terminal: ITerminal) {
diff --git a/src/SelectionManager.test.ts b/src/SelectionManager.test.ts
index 9a2ac405..24ba0100 100644
--- a/src/SelectionManager.test.ts
+++ b/src/SelectionManager.test.ts
@@ -8,9 +8,10 @@ import { CharMeasure } from './CharMeasure';
 import { SelectionManager, SelectionMode } from './SelectionManager';
 import { SelectionModel } from './SelectionModel';
 import { BufferSet } from './BufferSet';
-import { ITerminal, IBuffer, IBufferLine } from './Types';
+import { ITerminal, IBuffer } from './Types';
+import { IBufferLine } from './core/Types';
 import { MockTerminal } from './TestUtils.test';
-import { BufferLine, CellData } from './BufferLine';
+import { BufferLine, CellData } from './core/buffer/BufferLine';
 
 class TestMockTerminal extends MockTerminal {
   emit(event: string, data: any): void {}
diff --git a/src/SelectionManager.ts b/src/SelectionManager.ts
index dcd60068..dabcc9a4 100644
--- a/src/SelectionManager.ts
+++ b/src/SelectionManager.ts
@@ -3,13 +3,14 @@
  * @license MIT
  */
 
-import { ITerminal, ISelectionManager, IBuffer, IBufferLine, ISelectionRedrawRequestEvent } from './Types';
+import { ITerminal, ISelectionManager, IBuffer, ISelectionRedrawRequestEvent } from './Types';
+import { IBufferLine } from './core/Types';
 import { MouseHelper } from './MouseHelper';
 import * as Browser from './common/Platform';
 import { CharMeasure } from './CharMeasure';
 import { SelectionModel } from './SelectionModel';
 import { AltClickHandler } from './handlers/AltClickHandler';
-import { CellData } from './BufferLine';
+import { CellData } from './core/buffer/BufferLine';
 import { IDisposable } from 'xterm';
 import { EventEmitter2, IEvent } from './common/EventEmitter2';
 
diff --git a/src/Terminal.integration.ts b/src/Terminal.integration.ts
index 10043006..5e12d2a3 100644
--- a/src/Terminal.integration.ts
+++ b/src/Terminal.integration.ts
@@ -13,9 +13,8 @@ import * as path from 'path';
 import * as pty from 'node-pty';
 import { assert } from 'chai';
 import { Terminal } from './Terminal';
-import { WHITESPACE_CELL_CHAR } from './Buffer';
 import { IViewport } from './Types';
-import { CellData } from './BufferLine';
+import { CellData, WHITESPACE_CELL_CHAR } from './core/buffer/BufferLine';
 
 class TestTerminal extends Terminal {
   innerWrite(): void { this._innerWrite(); }
diff --git a/src/Terminal.test.ts b/src/Terminal.test.ts
index 69fbb8e2..9b5fa9c8 100644
--- a/src/Terminal.test.ts
+++ b/src/Terminal.test.ts
@@ -6,8 +6,7 @@
 import { assert, expect } from 'chai';
 import { Terminal } from './Terminal';
 import { MockViewport, MockCompositionHelper, MockRenderer } from './TestUtils.test';
-import { DEFAULT_ATTR_DATA } from './Buffer';
-import { CellData } from './BufferLine';
+import { CellData, DEFAULT_ATTR_DATA } from './core/buffer/BufferLine';
 
 const INIT_COLS = 80;
 const INIT_ROWS = 24;
diff --git a/src/Terminal.ts b/src/Terminal.ts
index 3fe5b590..6da60458 100644
--- a/src/Terminal.ts
+++ b/src/Terminal.ts
@@ -21,10 +21,10 @@
  *   http://linux.die.net/man/7/urxvt
  */
 
-import { IInputHandlingTerminal, IViewport, ICompositionHelper, ITerminalOptions, ITerminal, IBrowser, ILinkifier, ILinkMatcherOptions, CustomKeyEventHandler, LinkMatcherHandler, CharacterJoinerHandler, IBufferLine, IAttributeData, IMouseZoneManager } from './Types';
+import { IInputHandlingTerminal, IViewport, ICompositionHelper, ITerminalOptions, ITerminal, IBrowser, ILinkifier, ILinkMatcherOptions, CustomKeyEventHandler, LinkMatcherHandler, CharacterJoinerHandler, IMouseZoneManager } from './Types';
 import { IRenderer } from './renderer/Types';
 import { BufferSet } from './BufferSet';
-import { Buffer, MAX_BUFFER_SIZE, DEFAULT_ATTR_DATA } from './Buffer';
+import { Buffer, MAX_BUFFER_SIZE } from './Buffer';
 import { CompositionHelper } from './CompositionHelper';
 import { EventEmitter } from './common/EventEmitter';
 import { Viewport } from './Viewport';
@@ -48,10 +48,10 @@ import { removeTerminalFromCache } from './renderer/atlas/CharAtlasCache';
 import { DomRenderer } from './renderer/dom/DomRenderer';
 import { IKeyboardEvent } from './common/Types';
 import { evaluateKeyboardEvent } from './core/input/Keyboard';
-import { KeyboardResultType, ICharset } from './core/Types';
+import { KeyboardResultType, ICharset, IBufferLine, IAttributeData } from './core/Types';
 import { clone } from './common/Clone';
 import { EventEmitter2, IEvent } from './common/EventEmitter2';
-import { Attributes } from './BufferLine';
+import { Attributes, DEFAULT_ATTR_DATA } from './core/buffer/BufferLine';
 import { applyWindowsMode } from './WindowsMode';
 
 // Let it work inside Node.js for automated testing purposes.
diff --git a/src/TestUtils.test.ts b/src/TestUtils.test.ts
index 92018d1f..1d5008c8 100644
--- a/src/TestUtils.test.ts
+++ b/src/TestUtils.test.ts
@@ -4,13 +4,14 @@
  */
 
 import { IColorSet, IRenderer, IRenderDimensions, IColorManager } from './renderer/Types';
-import { IInputHandlingTerminal, IViewport, ICompositionHelper, ITerminal, IBuffer, IBufferSet, IBrowser, ICharMeasure, ISelectionManager, ITerminalOptions, ILinkifier, IMouseHelper, ILinkMatcherOptions, CharacterJoinerHandler, IBufferLine, IBufferStringIterator, ICellData, IAttributeData } from './Types';
+import { IInputHandlingTerminal, IViewport, ICompositionHelper, ITerminal, IBuffer, IBufferSet, IBrowser, ICharMeasure, ISelectionManager, ITerminalOptions, ILinkifier, IMouseHelper, ILinkMatcherOptions, CharacterJoinerHandler, IBufferStringIterator } from './Types';
+import { IBufferLine, ICellData, IAttributeData } from './core/Types';
 import { ICircularList, XtermListener } from './common/Types';
 import { Buffer } from './Buffer';
 import * as Browser from './common/Platform';
 import { ITheme, IDisposable, IMarker, IEvent } from 'xterm';
 import { Terminal } from './Terminal';
-import { AttributeData } from './BufferLine';
+import { AttributeData } from './core/buffer/BufferLine';
 
 export class TestTerminal extends Terminal {
   writeSync(data: string): void {
diff --git a/src/Types.ts b/src/Types.ts
index e603e92b..56feb71f 100644
--- a/src/Types.ts
+++ b/src/Types.ts
@@ -5,13 +5,12 @@
 
 import { Terminal as PublicTerminal, ITerminalOptions as IPublicTerminalOptions, IEventEmitter, IDisposable } from 'xterm';
 import { IColorSet, IRenderer } from './renderer/Types';
-import { ICharset } from './core/Types';
+import { ICharset, IAttributeData, ICellData, IBufferLine, CharData } from './core/Types';
 import { ICircularList } from './common/Types';
 import { IEvent } from './common/EventEmitter2';
 
 export type CustomKeyEventHandler = (event: KeyboardEvent) => boolean;
 
-export type CharData = [number, string, number, number];
 export type LineData = CharData[];
 
 export type LinkMatcherHandler = (event: MouseEvent, uri: string) => void;
@@ -525,85 +524,6 @@ export interface IEscapeSequenceParser extends IDisposable {
   clearErrorHandler(): void;
 }
 
-/** RGB color type */
-export type IColorRGB = [number, number, number];
-
-/** Attribute data */
-export interface IAttributeData {
-  fg: number;
-  bg: number;
-
-  clone(): IAttributeData;
-
-  // flags
-  isInverse(): number;
-  isBold(): number;
-  isUnderline(): number;
-  isBlink(): number;
-  isInvisible(): number;
-  isItalic(): number;
-  isDim(): number;
-
-  // color modes
-  getFgColorMode(): number;
-  getBgColorMode(): number;
-  isFgRGB(): boolean;
-  isBgRGB(): boolean;
-  isFgPalette(): boolean;
-  isBgPalette(): boolean;
-  isFgDefault(): boolean;
-  isBgDefault(): boolean;
-
-  // colors
-  getFgColor(): number;
-  getBgColor(): number;
-}
-
-/** Cell data */
-export interface ICellData extends IAttributeData {
-  content: number;
-  combinedData: string;
-  isCombined(): number;
-  getWidth(): number;
-  getChars(): string;
-  getCode(): number;
-  setFromCharData(value: CharData): void;
-  getAsCharData(): CharData;
-}
-
-/**
- * Interface for a line in the terminal buffer.
- */
-export interface IBufferLine {
-  length: number;
-  isWrapped: boolean;
-  get(index: number): CharData;
-  set(index: number, value: CharData): void;
-  loadCell(index: number, cell: ICellData): ICellData;
-  setCell(index: number, cell: ICellData): void;
-  setCellFromCodePoint(index: number, codePoint: number, width: number, fg: number, bg: number): void;
-  addCodepointToCell(index: number, codePoint: number): void;
-  insertCells(pos: number, n: number, ch: ICellData): void;
-  deleteCells(pos: number, n: number, fill: ICellData): void;
-  replaceCells(start: number, end: number, fill: ICellData): void;
-  resize(cols: number, fill: ICellData): void;
-  fill(fillCellData: ICellData): void;
-  copyFrom(line: IBufferLine): void;
-  clone(): IBufferLine;
-  getTrimmedLength(): number;
-  translateToString(trimRight?: boolean, startCol?: number, endCol?: number): string;
-
-  /* direct access to cell attrs */
-  getWidth(index: number): number;
-  hasWidth(index: number): number;
-  getFg(index: number): number;
-  getBg(index: number): number;
-  hasContent(index: number): number;
-  getCodePoint(index: number): number;
-  isCombined(index: number): number;
-  getString(index: number): string;
-}
-
 export interface IMouseZoneManager extends IDisposable {
   add(zone: IMouseZone): void;
   clearAll(start?: number, end?: number): void;
diff --git a/src/WindowsMode.ts b/src/WindowsMode.ts
index ac1d193e..d7b4bcae 100644
--- a/src/WindowsMode.ts
+++ b/src/WindowsMode.ts
@@ -5,7 +5,7 @@
 
 import { IDisposable } from 'xterm';
 import { ITerminal } from './Types';
-import { CHAR_DATA_CODE_INDEX, NULL_CELL_CODE, WHITESPACE_CELL_CODE } from './Buffer';
+import { CHAR_DATA_CODE_INDEX, NULL_CELL_CODE, WHITESPACE_CELL_CODE } from './core/buffer/BufferLine';
 
 export function applyWindowsMode(terminal: ITerminal): IDisposable {
   // Winpty does not support wraparound mode which means that lines will never
diff --git a/src/common/Types.ts b/src/common/Types.ts
index b2111bfc..717de359 100644
--- a/src/common/Types.ts
+++ b/src/common/Types.ts
@@ -6,6 +6,8 @@
 import { IEvent, EventEmitter2 } from './EventEmitter2';
 import { IDeleteEvent, IInsertEvent } from './CircularList';
 
+export const DEFAULT_COLOR = 256;
+
 export interface IDisposable {
   dispose(): void;
 }
diff --git a/src/core/Types.ts b/src/core/Types.ts
index 4001e448..ae9274b8 100644
--- a/src/core/Types.ts
+++ b/src/core/Types.ts
@@ -19,3 +19,82 @@ export interface IKeyboardResult {
 export interface ICharset {
   [key: string]: string;
 }
+
+export type CharData = [number, string, number, number];
+export type IColorRGB = [number, number, number];
+
+/** Attribute data */
+export interface IAttributeData {
+  fg: number;
+  bg: number;
+
+  clone(): IAttributeData;
+
+  // flags
+  isInverse(): number;
+  isBold(): number;
+  isUnderline(): number;
+  isBlink(): number;
+  isInvisible(): number;
+  isItalic(): number;
+  isDim(): number;
+
+  // color modes
+  getFgColorMode(): number;
+  getBgColorMode(): number;
+  isFgRGB(): boolean;
+  isBgRGB(): boolean;
+  isFgPalette(): boolean;
+  isBgPalette(): boolean;
+  isFgDefault(): boolean;
+  isBgDefault(): boolean;
+
+  // colors
+  getFgColor(): number;
+  getBgColor(): number;
+}
+
+/** Cell data */
+export interface ICellData extends IAttributeData {
+  content: number;
+  combinedData: string;
+  isCombined(): number;
+  getWidth(): number;
+  getChars(): string;
+  getCode(): number;
+  setFromCharData(value: CharData): void;
+  getAsCharData(): CharData;
+}
+
+/**
+ * Interface for a line in the terminal buffer.
+ */
+export interface IBufferLine {
+  length: number;
+  isWrapped: boolean;
+  get(index: number): CharData;
+  set(index: number, value: CharData): void;
+  loadCell(index: number, cell: ICellData): ICellData;
+  setCell(index: number, cell: ICellData): void;
+  setCellFromCodePoint(index: number, codePoint: number, width: number, fg: number, bg: number): void;
+  addCodepointToCell(index: number, codePoint: number): void;
+  insertCells(pos: number, n: number, ch: ICellData): void;
+  deleteCells(pos: number, n: number, fill: ICellData): void;
+  replaceCells(start: number, end: number, fill: ICellData): void;
+  resize(cols: number, fill: ICellData): void;
+  fill(fillCellData: ICellData): void;
+  copyFrom(line: IBufferLine): void;
+  clone(): IBufferLine;
+  getTrimmedLength(): number;
+  translateToString(trimRight?: boolean, startCol?: number, endCol?: number): string;
+
+  /* direct access to cell attrs */
+  getWidth(index: number): number;
+  hasWidth(index: number): number;
+  getFg(index: number): number;
+  getBg(index: number): number;
+  hasContent(index: number): number;
+  getCodePoint(index: number): number;
+  isCombined(index: number): number;
+  getString(index: number): string;
+}
diff --git a/src/BufferLine.test.ts b/src/core/buffer/BufferLine.test.ts
similarity index 95%
rename from src/BufferLine.test.ts
rename to src/core/buffer/BufferLine.test.ts
index 5b029cb8..c42b372e 100644
--- a/src/BufferLine.test.ts
+++ b/src/core/buffer/BufferLine.test.ts
@@ -3,10 +3,8 @@
  * @license MIT
  */
 import * as chai from 'chai';
-import { BufferLine, CellData, Content } from './BufferLine';
-import { CharData, IBufferLine } from './Types';
-import { NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE, DEFAULT_ATTR } from './Buffer';
-
+import { BufferLine, CellData, Content, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE, DEFAULT_ATTR } from './BufferLine';
+import { CharData, IBufferLine } from '../Types';
 
 class TestBufferLine extends BufferLine {
   public get combined(): {[index: number]: string} {
@@ -57,7 +55,7 @@ describe('BufferLine', function(): void {
     chai.expect(line.length).equals(10);
     chai.expect(line.loadCell(0, new CellData()).getAsCharData()).eql([0, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE]);
     chai.expect(line.isWrapped).equals(false);
-    line = new TestBufferLine(10, null, true);
+    line = new TestBufferLine(10, undefined, true);
     chai.expect(line.length).equals(10);
     chai.expect(line.loadCell(0, new CellData()).getAsCharData()).eql([0, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE]);
     chai.expect(line.isWrapped).equals(true);
@@ -127,7 +125,7 @@ describe('BufferLine', function(): void {
     ]);
   });
   it('clone', function(): void {
-    const line = new TestBufferLine(5, null, true);
+    const line = new TestBufferLine(5, undefined, true);
     line.setCell(0, CellData.fromCharData([1, 'a', 0, 'a'.charCodeAt(0)]));
     line.setCell(1, CellData.fromCharData([2, 'b', 0, 'b'.charCodeAt(0)]));
     line.setCell(2, CellData.fromCharData([3, 'c', 0, 'c'.charCodeAt(0)]));
@@ -167,27 +165,27 @@ describe('BufferLine', function(): void {
     it('enlarge(false)', function(): void {
       const line = new TestBufferLine(5, CellData.fromCharData([1, 'a', 0, 'a'.charCodeAt(0)]), false);
       line.resize(10, CellData.fromCharData([1, 'a', 0, 'a'.charCodeAt(0)]));
-      chai.expect(line.toArray()).eql(Array(10).fill([1, 'a', 0, 'a'.charCodeAt(0)]));
+      chai.expect(line.toArray()).eql((Array(10) as any).fill([1, 'a', 0, 'a'.charCodeAt(0)]));
     });
     it('enlarge(true)', function(): void {
       const line = new TestBufferLine(5, CellData.fromCharData([1, 'a', 0, 'a'.charCodeAt(0)]), false);
       line.resize(10, CellData.fromCharData([1, 'a', 0, 'a'.charCodeAt(0)]));
-      chai.expect(line.toArray()).eql(Array(10).fill([1, 'a', 0, 'a'.charCodeAt(0)]));
+      chai.expect(line.toArray()).eql((Array(10) as any).fill([1, 'a', 0, 'a'.charCodeAt(0)]));
     });
     it('shrink(true) - should apply new size', function(): void {
       const line = new TestBufferLine(10, CellData.fromCharData([1, 'a', 0, 'a'.charCodeAt(0)]), false);
       line.resize(5, CellData.fromCharData([1, 'a', 0, 'a'.charCodeAt(0)]));
-      chai.expect(line.toArray()).eql(Array(5).fill([1, 'a', 0, 'a'.charCodeAt(0)]));
+      chai.expect(line.toArray()).eql((Array(5) as any).fill([1, 'a', 0, 'a'.charCodeAt(0)]));
     });
     it('shrink to 0 length', function(): void {
       const line = new TestBufferLine(10, CellData.fromCharData([1, 'a', 0, 'a'.charCodeAt(0)]), false);
       line.resize(0, CellData.fromCharData([1, 'a', 0, 'a'.charCodeAt(0)]));
-      chai.expect(line.toArray()).eql(Array(0).fill([1, 'a', 0, 'a'.charCodeAt(0)]));
+      chai.expect(line.toArray()).eql((Array(0) as any).fill([1, 'a', 0, 'a'.charCodeAt(0)]));
     });
     it('should remove combining data on replaced cells after shrinking then enlarging', () => {
       const line = new TestBufferLine(10, CellData.fromCharData([1, 'a', 0, 'a'.charCodeAt(0)]), false);
-      line.set(2, [ null, '😁', 1, '😁'.charCodeAt(0) ]);
-      line.set(9, [ null, '😁', 1, '😁'.charCodeAt(0) ]);
+      line.set(2, [ 0, '😁', 1, '😁'.charCodeAt(0) ]);
+      line.set(9, [ 0, '😁', 1, '😁'.charCodeAt(0) ]);
       chai.expect(line.translateToString()).eql('aa😁aaaaaa😁');
       chai.expect(Object.keys(line.combined).length).eql(2);
       line.resize(5, CellData.fromCharData([1, 'a', 0, 'a'.charCodeAt(0)]));
@@ -224,7 +222,7 @@ describe('BufferLine', function(): void {
       const line = new TestBufferLine(10, CellData.fromCharData([DEFAULT_ATTR, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE]), false);
       line.setCell(0, CellData.fromCharData([1, 'a', 1, 'a'.charCodeAt(0)]));
       line.setCell(2, CellData.fromCharData([1, '１', 2, '１'.charCodeAt(0)]));
-      line.setCell(3, CellData.fromCharData([0, '', 0, undefined]));
+      line.setCell(3, CellData.fromCharData([0, '', 0, 0]));
       chai.expect(line.getTrimmedLength()).equal(4); // also counts null cell after fullwidth
     });
   });
@@ -284,11 +282,11 @@ describe('BufferLine', function(): void {
       const line = new TestBufferLine(10, CellData.fromCharData([DEFAULT_ATTR, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE]), false);
       line.setCell(0, CellData.fromCharData([1, 'a', 1, 'a'.charCodeAt(0)]));
       line.setCell(2, CellData.fromCharData([1, '１', 2, '１'.charCodeAt(0)]));
-      line.setCell(3, CellData.fromCharData([0, '', 0, undefined]));
+      line.setCell(3, CellData.fromCharData([0, '', 0, 0]));
       line.setCell(5, CellData.fromCharData([1, '１', 2, '１'.charCodeAt(0)]));
-      line.setCell(6, CellData.fromCharData([0, '', 0, undefined]));
+      line.setCell(6, CellData.fromCharData([0, '', 0, 0]));
       line.setCell(7, CellData.fromCharData([1, '１', 2, '１'.charCodeAt(0)]));
-      line.setCell(8, CellData.fromCharData([0, '', 0, undefined]));
+      line.setCell(8, CellData.fromCharData([0, '', 0, 0]));
       chai.expect(line.translateToString(false)).equal('a １ １１ ');
       chai.expect(line.translateToString(true)).equal('a １ １１');
       chai.expect(line.translateToString(false, 0, 7)).equal('a １ １');
diff --git a/src/BufferLine.ts b/src/core/buffer/BufferLine.ts
similarity index 94%
rename from src/BufferLine.ts
rename to src/core/buffer/BufferLine.ts
index d2f7af40..154cc598 100644
--- a/src/BufferLine.ts
+++ b/src/core/buffer/BufferLine.ts
@@ -2,10 +2,34 @@
  * Copyright (c) 2018 The xterm.js authors. All rights reserved.
  * @license MIT
  */
-import { CharData, IBufferLine, ICellData, IColorRGB, IAttributeData } from './Types';
-import { NULL_CELL_CODE, NULL_CELL_WIDTH, NULL_CELL_CHAR, CHAR_DATA_CHAR_INDEX, CHAR_DATA_WIDTH_INDEX, WHITESPACE_CELL_CHAR, CHAR_DATA_ATTR_INDEX } from './Buffer';
-import { stringFromCodePoint } from './core/input/TextDecoder';
+import { CharData, IBufferLine, ICellData, IColorRGB, IAttributeData } from '../Types';
+import { stringFromCodePoint } from '../input/TextDecoder';
+import { DEFAULT_COLOR } from '../../common/Types';
 
+export const DEFAULT_ATTR = (0 << 18) | (DEFAULT_COLOR << 9) | (256 << 0);
+
+export const CHAR_DATA_ATTR_INDEX = 0;
+export const CHAR_DATA_CHAR_INDEX = 1;
+export const CHAR_DATA_WIDTH_INDEX = 2;
+export const CHAR_DATA_CODE_INDEX = 3;
+
+/**
+ * Null cell - a real empty cell (containing nothing).
+ * Note that code should always be 0 for a null cell as
+ * several test condition of the buffer line rely on this.
+ */
+export const NULL_CELL_CHAR = '';
+export const NULL_CELL_WIDTH = 1;
+export const NULL_CELL_CODE = 0;
+
+/**
+ * Whitespace cell.
+ * This is meant as a replacement for empty cells when needed
+ * during rendering lines to preserve correct aligment.
+ */
+export const WHITESPACE_CELL_CHAR = ' ';
+export const WHITESPACE_CELL_WIDTH = 1;
+export const WHITESPACE_CELL_CODE = 32;
 
 /**
  * buffer memory layout:
@@ -193,6 +217,8 @@ export class AttributeData implements IAttributeData {
   }
 }
 
+export const DEFAULT_ATTR_DATA = new AttributeData();
+
 /**
  * CellData - represents a single Cell in the terminal buffer.
  */
@@ -299,17 +325,15 @@ export class CellData extends AttributeData implements ICellData {
  * memory allocs / GC pressure can be greatly reduced by reusing the CellData object.
  */
 export class BufferLine implements IBufferLine {
-  protected _data: Uint32Array | null = null;
+  protected _data: Uint32Array;
   protected _combined: {[index: number]: string} = {};
   public length: number;
 
   constructor(cols: number, fillCellData?: ICellData, public isWrapped: boolean = false) {
-    if (cols) {
-      this._data = new Uint32Array(cols * CELL_SIZE);
-      const cell = fillCellData || CellData.fromCharData([0, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE]);
-      for (let i = 0; i < cols; ++i) {
-        this.setCell(i, cell);
-      }
+    this._data = new Uint32Array(cols * CELL_SIZE);
+    const cell = fillCellData || CellData.fromCharData([0, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE]);
+    for (let i = 0; i < cols; ++i) {
+      this.setCell(i, cell);
     }
     this.length = cols;
   }
@@ -547,7 +571,7 @@ export class BufferLine implements IBufferLine {
           }
         }
       } else {
-        this._data = null;
+        this._data = new Uint32Array(0);
         this._combined = {};
       }
     }
diff --git a/src/handlers/AltClickHandler.ts b/src/handlers/AltClickHandler.ts
index 9286421e..5cf60fa6 100644
--- a/src/handlers/AltClickHandler.ts
+++ b/src/handlers/AltClickHandler.ts
@@ -3,7 +3,8 @@
  * @license MIT
  */
 
-import { ITerminal, IBufferLine } from '../Types';
+import { ITerminal } from '../Types';
+import { IBufferLine } from '../core/Types';
 import { ICircularList } from '../common/Types';
 import { C0 } from '../common/data/EscapeSequences';
 
diff --git a/src/renderer/BaseRenderLayer.ts b/src/renderer/BaseRenderLayer.ts
index ace1f678..ce50a651 100644
--- a/src/renderer/BaseRenderLayer.ts
+++ b/src/renderer/BaseRenderLayer.ts
@@ -4,12 +4,13 @@
  */
 
 import { IRenderLayer, IColorSet, IRenderDimensions } from './Types';
-import { ITerminal, ICellData } from '../Types';
-import { DIM_OPACITY, INVERTED_DEFAULT_COLOR, IGlyphIdentifier, DEFAULT_COLOR } from './atlas/Types';
+import { ITerminal } from '../Types';
+import { ICellData } from '../core/Types';
+import { DEFAULT_COLOR } from '../common/Types';
+import { DIM_OPACITY, INVERTED_DEFAULT_COLOR, IGlyphIdentifier } from './atlas/Types';
 import BaseCharAtlas from './atlas/BaseCharAtlas';
 import { acquireCharAtlas } from './atlas/CharAtlasCache';
-import { CellData, AttributeData } from '../BufferLine';
-import { WHITESPACE_CELL_CHAR, WHITESPACE_CELL_CODE } from '../Buffer';
+import { CellData, AttributeData, WHITESPACE_CELL_CHAR, WHITESPACE_CELL_CODE } from '../core/buffer/BufferLine';
 import { JoinedCellData } from './CharacterJoinerRegistry';
 
 export abstract class BaseRenderLayer implements IRenderLayer {
diff --git a/src/renderer/CharacterJoinerRegistry.test.ts b/src/renderer/CharacterJoinerRegistry.test.ts
index 2ccfd197..948985a4 100644
--- a/src/renderer/CharacterJoinerRegistry.test.ts
+++ b/src/renderer/CharacterJoinerRegistry.test.ts
@@ -1,3 +1,8 @@
+/**
+ * Copyright (c) 2018 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
 import { assert } from 'chai';
 
 import { MockTerminal, MockBuffer } from '../TestUtils.test';
@@ -5,8 +10,8 @@ import { CircularList } from '../common/CircularList';
 
 import { ICharacterJoinerRegistry } from './Types';
 import { CharacterJoinerRegistry } from './CharacterJoinerRegistry';
-import { BufferLine, CellData } from '../BufferLine';
-import { IBufferLine } from '../Types';
+import { BufferLine, CellData } from '../core/buffer/BufferLine';
+import { IBufferLine } from '../core/Types';
 
 describe('CharacterJoinerRegistry', () => {
   let registry: ICharacterJoinerRegistry;
diff --git a/src/renderer/CharacterJoinerRegistry.ts b/src/renderer/CharacterJoinerRegistry.ts
index 7a3bb8e0..3302c312 100644
--- a/src/renderer/CharacterJoinerRegistry.ts
+++ b/src/renderer/CharacterJoinerRegistry.ts
@@ -1,7 +1,12 @@
-import { ITerminal, IBufferLine, ICellData, CharData } from '../Types';
+/**
+ * Copyright (c) 2018 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { ITerminal } from '../Types';
+import { IBufferLine, ICellData, CharData } from '../core/Types';
 import { ICharacterJoinerRegistry, ICharacterJoiner } from './Types';
-import { CellData, Content, AttributeData } from '../BufferLine';
-import { WHITESPACE_CELL_CHAR } from '../Buffer';
+import { CellData, Content, AttributeData, WHITESPACE_CELL_CHAR } from '../core/buffer/BufferLine';
 
 export class JoinedCellData extends AttributeData implements ICellData {
   private _width: number;
diff --git a/src/renderer/CursorRenderLayer.ts b/src/renderer/CursorRenderLayer.ts
index c3b751fa..3e8af02d 100644
--- a/src/renderer/CursorRenderLayer.ts
+++ b/src/renderer/CursorRenderLayer.ts
@@ -5,8 +5,9 @@
 
 import { IColorSet, IRenderDimensions } from './Types';
 import { BaseRenderLayer } from './BaseRenderLayer';
-import { ITerminal, ICellData } from '../Types';
-import { CellData } from '../BufferLine';
+import { ITerminal } from '../Types';
+import { ICellData } from '../core/Types';
+import { CellData } from '../core/buffer/BufferLine';
 
 interface ICursorState {
   x: number;
diff --git a/src/renderer/TextRenderLayer.ts b/src/renderer/TextRenderLayer.ts
index d54008b8..8be5665c 100644
--- a/src/renderer/TextRenderLayer.ts
+++ b/src/renderer/TextRenderLayer.ts
@@ -3,12 +3,12 @@
  * @license MIT
  */
 
-import { NULL_CELL_CODE } from '../Buffer';
 import { IColorSet, IRenderDimensions, ICharacterJoinerRegistry } from './Types';
-import { CharData, ITerminal, ICellData } from '../Types';
+import { ITerminal } from '../Types';
+import { CharData, ICellData } from '../core/Types';
 import { GridCache } from './GridCache';
 import { BaseRenderLayer } from './BaseRenderLayer';
-import { CellData, AttributeData, Content } from '../BufferLine';
+import { CellData, AttributeData, Content, NULL_CELL_CODE } from '../core/buffer/BufferLine';
 import { JoinedCellData } from './CharacterJoinerRegistry';
 
 /**
diff --git a/src/renderer/atlas/CharAtlasUtils.ts b/src/renderer/atlas/CharAtlasUtils.ts
index 5b1add39..c2eb2e1e 100644
--- a/src/renderer/atlas/CharAtlasUtils.ts
+++ b/src/renderer/atlas/CharAtlasUtils.ts
@@ -5,7 +5,8 @@
 
 import { ITerminal } from '../../Types';
 import { IColorSet } from '../Types';
-import { DEFAULT_COLOR, ICharAtlasConfig } from './Types';
+import { ICharAtlasConfig } from './Types';
+import { DEFAULT_COLOR } from '../../common/Types';
 
 export function generateConfig(scaledCharWidth: number, scaledCharHeight: number, terminal: ITerminal, colors: IColorSet): ICharAtlasConfig {
   // null out some fields that don't matter
diff --git a/src/renderer/atlas/StaticCharAtlas.ts b/src/renderer/atlas/StaticCharAtlas.ts
index b54c833e..66beb363 100644
--- a/src/renderer/atlas/StaticCharAtlas.ts
+++ b/src/renderer/atlas/StaticCharAtlas.ts
@@ -3,10 +3,11 @@
  * @license MIT
  */
 
-import { DIM_OPACITY, IGlyphIdentifier, DEFAULT_COLOR, ICharAtlasConfig, CHAR_ATLAS_CELL_SPACING } from './Types';
+import { DIM_OPACITY, IGlyphIdentifier, ICharAtlasConfig, CHAR_ATLAS_CELL_SPACING } from './Types';
 import { generateStaticCharAtlasTexture } from './CharAtlasGenerator';
 import BaseCharAtlas from './BaseCharAtlas';
 import { is256Color } from './CharAtlasUtils';
+import { DEFAULT_COLOR } from '../../common/Types';
 
 export default class StaticCharAtlas extends BaseCharAtlas {
   private _texture: HTMLCanvasElement | ImageBitmap;
diff --git a/src/renderer/atlas/Types.ts b/src/renderer/atlas/Types.ts
index 38923b2f..2459c72f 100644
--- a/src/renderer/atlas/Types.ts
+++ b/src/renderer/atlas/Types.ts
@@ -6,7 +6,6 @@
 import { FontWeight } from 'xterm';
 import { IColorSet } from '../Types';
 
-export const DEFAULT_COLOR = 256;
 export const INVERTED_DEFAULT_COLOR = 257;
 export const DIM_OPACITY = 0.5;
 
diff --git a/src/renderer/dom/DomRendererRowFactory.test.ts b/src/renderer/dom/DomRendererRowFactory.test.ts
index 076f5d6a..b2530595 100644
--- a/src/renderer/dom/DomRendererRowFactory.test.ts
+++ b/src/renderer/dom/DomRendererRowFactory.test.ts
@@ -6,9 +6,9 @@
 import jsdom = require('jsdom');
 import { assert } from 'chai';
 import { DomRendererRowFactory } from './DomRendererRowFactory';
-import { DEFAULT_ATTR, NULL_CELL_CODE, NULL_CELL_WIDTH, NULL_CELL_CHAR, DEFAULT_ATTR_DATA } from '../../Buffer';
-import { BufferLine, CellData, FgFlags, BgFlags, Attributes } from '../../BufferLine';
-import { IBufferLine, ITerminalOptions } from '../../Types';
+import { BufferLine, CellData, FgFlags, BgFlags, Attributes, NULL_CELL_CODE, NULL_CELL_WIDTH, NULL_CELL_CHAR, DEFAULT_ATTR, DEFAULT_ATTR_DATA } from '../../core/buffer/BufferLine';
+import { ITerminalOptions } from '../../Types';
+import { IBufferLine } from '../../core/Types';
 
 describe('DomRendererRowFactory', () => {
   let dom: jsdom.JSDOM;
diff --git a/src/renderer/dom/DomRendererRowFactory.ts b/src/renderer/dom/DomRendererRowFactory.ts
index 60e2d509..85ef586e 100644
--- a/src/renderer/dom/DomRendererRowFactory.ts
+++ b/src/renderer/dom/DomRendererRowFactory.ts
@@ -3,10 +3,10 @@
  * @license MIT
  */
 
-import {  NULL_CELL_CODE, WHITESPACE_CELL_CHAR } from '../../Buffer';
-import { IBufferLine, ITerminalOptions } from '../../Types';
+import { ITerminalOptions } from '../../Types';
+import { IBufferLine } from '../../core/Types';
 import { INVERTED_DEFAULT_COLOR } from '../atlas/Types';
-import { CellData, AttributeData } from '../../BufferLine';
+import { CellData, AttributeData, NULL_CELL_CODE, WHITESPACE_CELL_CHAR } from '../../core/buffer/BufferLine';
 
 export const BOLD_CLASS = 'xterm-bold';
 export const DIM_CLASS = 'xterm-dim';