Initial commit

.npmignore

@@ -0,0 +1,3 @@
+test
+benchmark
+.*

.travis.yml

@@ -0,0 +1,3 @@
+language: node_js
+node_js:
+  - 0.10

CHS.js

@@ -0,0 +1,118 @@
+/**
+ * CHS constructor
+ * @param {Object|Buffer} data
+ */
+function CHS( cylinder, head, sector ) {
+
+  if( !(this instanceof CHS) )
+    return new CHS( data )
+
+  this.cylinder = 0 // [0,1023]
+  this.head     = 0 // [0,255]
+  this.sector   = 0 // [1,63]
+
+  this._buffer = new Buffer([ 0xFE, 0xFF, 0xFF ])
+
+  if( cylinder instanceof Buffer ) {
+    this.buffer = data
+  } else {
+    this.cylinder = cylinder || 0
+    this.head     = head || 0
+    this.sector   = sector || 0
+  }
+
+  // Update internal buffer
+  void this.buffer
+
+}
+
+// Exports
+module.exports = CHS
+
+/**
+ * Set to the CHS of a Logical Block Address
+ * @param {Number} lba
+ * @param {Number} hpt Heads per Track
+ * @param {Number} spt Sectors per Track
+ */
+CHS.fromLBA = function( lba, hpt, spt ) {
+  return new CHS().setLBA( lba, hpt, spt )
+}
+
+/**
+ * CHS prototype
+ * @type {Object}
+ */
+CHS.prototype = {
+
+  constructor: CHS,
+
+  get buffer() {
+
+    var cylinder = this.cylinder & 0xFF
+    var head = this.head
+    var sector = ( this.cylinder >> 2 ) & 0xC0
+        sector = sector ^ this.sector
+
+    this._buffer[0] = head
+    this._buffer[1] = sector
+    this._buffer[2] = cylinder
+
+    return this._buffer.slice()
+
+  },
+
+  set buffer( value ) {
+
+    if( !(value instanceof Buffer) ) {
+      throw new TypeError( 'Value must be a buffer' )
+    }
+
+    value.copy( this._buffer )
+
+    this.head = this._buffer[0]
+
+    // Sector in bits 5–0;
+    // bits 7–6 are high bits of cylinder
+    this.sector = this._buffer[1] & 0x3F // 00111111b
+
+    // Bits 7-6 from sector & bits 7–0 of cylinder
+    this.cylinder = ( this._buffer[1] & 0xC0 ) << 2 // 11000000b
+    this.cylinder = this.cylinder | this._buffer[2]
+
+  },
+
+  /**
+   * Set to the CHS of a Logical Block Address
+   * @param {Number} lba
+   * @param {Number} hpt Heads per Track
+   * @param {Number} spt Sectors per Track
+   */
+  setLBA: function( lba, hpt, spt ) {
+    this.cylinder = ( lba / ( spt * hpt )) | 0
+    this.head     = ( lba / spt ) % hpt
+    this.sector   = ( lba % spt ) + 1
+    return this
+  },
+
+  /**
+   * Get the Logical Block Address corresponding
+   * to the given disk geometry
+   * @param {Number} hpt Heads per Track
+   * @param {Number} spt Sectors per Track
+   */
+  getLBA: function( hpt, spt ) {
+    return ( this.cylinder * hpt + this.head ) *
+      spt + ( this.sector - 1 )
+  },
+
+  /**
+   * @see #getLBA()
+   * @param {Number} hpt Heads per Track
+   * @param {Number} spt Sectors per Track
+   */
+  toLBA: function( hpt, spt ) {
+    return this.getLBA( hpt, spt )
+  }
+
+}

LICENSE.md

@@ -0,0 +1,22 @@
+
+## License (MIT)
+
+Copyright (c) 2014 [Jonas Hermsmeier](http://jhermsmeier.de)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy 
+of this software and associated documentation files (the "Software"), to deal 
+in the Software without restriction, including without limitation the rights 
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 
+copies of the Software, and to permit persons to whom the Software is 
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in 
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
+THE SOFTWARE.

README.md

@@ -0,0 +1,34 @@
+# CHS - Cylinder Head Sector Address
+[![build status](https://secure.travis-ci.org/jhermsmeier/node-chs.png)](http://travis-ci.org/jhermsmeier/node-chs)
+[![NPM version](https://badge.fury.io/js/chs.png)](https://npmjs.org/chs)
+
+
+## Install via [npm](https://npmjs.org)
+
+```sh
+$ npm install chs
+```
+
+
+## Usage
+
+```js
+// Load module
+var CHS = require( 'chs' )
+// Create a CHS address
+var addr = new CHS( 5, 20, 8 )
+// Properties:
+var c = addr.cylinder
+var h = addr.head
+var s = addr.sector
+// Convert to an LBA (Logical Block Address)
+var lba = addr.toLBA( headsPerTrack, sectorsPerTrack )
+var lba = addr.toLBA( 12, 32 )
+// Set it to an LBA
+addr.setLBA( lba, headsPerTrack, sectorsPerTrack )
+addr.setLBA( 3150, 16, 63 )
+// Get it as a buffer
+var buf = addr.buffer
+// Set from buffer
+addr.buffer = new Buffer([ 0xFE, 0xFF, 0xFF ])
+```

package.json

@@ -0,0 +1,29 @@
+{
+  "name": "chs",
+  "version": "0.1.0",
+  "license": "MIT",
+  "description": "Cylinder-Head-Sector Address (CHS)",
+  "kewords": [],
+  "author": {
+    "name": "Jonas Hermsmeier",
+    "email": "jhermsmeier@gmail.com",
+    "url": "https://github.com/jhermsmeier"
+  },
+  "main": "CHS",
+  "scripts": {
+    "test": "node node_modules/mocha/bin/mocha"
+  },
+  "dependencies": {
+
+  },
+  "devDependencies": {
+    "mocha": ""
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/jhermsmeier/node-chs.git"
+  },
+  "bugs": {
+    "url": "https://github.com/jhermsmeier/node-chs/issues"
+  }
+}

test/chs.js

@@ -0,0 +1,62 @@
+var assert = require( 'assert' )
+var CHS = require( '../' )
+
+describe( 'CHS', function() {
+
+  it( 'should map the right LBAs corresponding to geometry', function() {
+
+    var chs = new CHS( 3, 2, 1 )
+
+    // For geometry 1020 16 63 of a disk with
+    // 1028160 sectors CHS 3 2 1 is LBA  3150=(3*16+2)* 63
+    assert.equal( chs.toLBA( 16, 63 ), 3150 )
+
+    // For geometry 1008 4 255 of a disk with
+    // 1028160 sectors CHS 3 2 1 is LBA  3570=(3*4+2)*255
+    assert.equal( chs.toLBA( 4, 255 ), 3570 )
+
+    // For geometry  64 255 63 of a disk with
+    // 1028160 sectors CHS 3 2 1 is LBA 48321=(3*255+2)* 63
+    assert.equal( chs.toLBA( 255, 63 ), 48321 )
+
+    // For geometry 2142 15 32 of a disk with
+    // 1028160 sectors CHS 3 2 1 is LBA  1504=(3*15+2)* 32
+    assert.equal( chs.toLBA( 15, 32 ), 1504 )
+
+  })
+
+  it( 'should map the right CHS to a given LBA with geometry', function() {
+
+    var chs = new CHS()
+
+    // For geometry 1020 16 63 of a disk with
+    // 1028160 sectors CHS 3 2 1 is LBA  3150=(3*16+2)* 63
+    chs.setLBA( 3150, 16, 63 )
+    assert.equal( chs.cylinder, 3 )
+    assert.equal( chs.head, 2 )
+    assert.equal( chs.sector, 1 )
+
+    // For geometry 1008 4 255 of a disk with
+    // 1028160 sectors CHS 3 2 1 is LBA  3570=(3*4+2)*255
+    chs.setLBA( 3570, 4, 255 )
+    assert.equal( chs.cylinder, 3 )
+    assert.equal( chs.head, 2 )
+    assert.equal( chs.sector, 1 )
+
+    // For geometry  64 255 63 of a disk with
+    // 1028160 sectors CHS 3 2 1 is LBA 48321=(3*255+2)* 63
+    chs.setLBA( 48321, 255, 63 )
+    assert.equal( chs.cylinder, 3 )
+    assert.equal( chs.head, 2 )
+    assert.equal( chs.sector, 1 )
+
+    // For geometry 2142 15 32 of a disk with
+    // 1028160 sectors CHS 3 2 1 is LBA  1504=(3*15+2)* 32
+    chs.setLBA( 1504, 15, 32 )
+    assert.equal( chs.cylinder, 3 )
+    assert.equal( chs.head, 2 )
+    assert.equal( chs.sector, 1 )
+
+  })
+
+})

test/mocha.opts

@@ -0,0 +1 @@
+--reporter=spec