Emulate the Cd-Rom drive from a USB stick

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Emulate the Cd-Rom drive from a USB stick

USB penDrive (C) http://en.wikipedia.org/wiki/File:Geil_David_1GB_AB.jpg

DVD disk (C) http://en.wikipedia.org/wiki/File:DVD.jpg

Introduction

This page explains how to turn a USB stick into a CD/DVD unit.
This results to be indispensable in some cases (see below) or simply easy (I think it's better to hold a USB stick in your pocket instead of a Cd or Dvd).

Why should I need for an external CdRom or Dvd drive ?

Not all the computers have one, for instance NetBooks, EePcs and so on or old computers have not. In addition to burning (but in that case you need a Cd/Dvd burner), watching movies, installing programs, it turns to be very useful to install the operating system from scratch or to repair an installation (when the operating system does not boots), by using PartPE for instance or simply to test a new operating system without installing it.

Can I use a Virtual Cd/Dvd ?

This is a really useful kind of software to use for installing programs distributed in Cd/Dvd. but this technique can't be used to install the Operating System, because in order to install and run a virtualization software you need an Operating System already up and running. That's why if you need to install the Operating System from scratch you need a real Cd/Dvd reader.
Good virtualization softwares to mount ISO immages are:
CloneDrive for Windows XP, Vista and 7, 32 and 64 bit.
CDemu (open source) for Linux.

But why do I need a CdRom Drive ? A standard USB stick isn't enought ?

A USB stick is useful when the operating system is already running: just copy the desired files, but if the problem itself is in the operating system that needs to be 'repaired' or if you need to install a different operating system, CdRom is invaluable.

On the internet you can find softwares that allow you to boot from any USB stick in order to install the operating system !

Yes, it's true, but it doesn't work on any computer. Furthermore you can not emulate any Cd or Dvd of any operating system, you need to get what is available.
For instance, to create a USB and install:
Linux you can use UNetBootin: it's a software that needs to be installed under Linux or Windows or Universal USB Installer
Windows Vista you can use A Bootable USB (can be used to install Windows 7 and Windows Server 2008 too): it's a software to be installed on your Pc but at least Windows Vista is required
Windows 7 better to use Windows7 USB DVD tool from Microsoft, here the direct download link. You need to install this software on a Pc running at least XP. Who owns Windows XP first needs to install .NET framework 2.0 and Image Mastering API v2.

Unfortunately these techniques does not work on any computer, especially the older ones, due to BIOS.

Here you can find a very interesting guide (in english) supplying many different techniques on how to make a USB pen drive bootable. This way it is possible to upgrade firmware (BIOS) or recover damaged disks.

You can use LAN boot to install or run an operating system !

Yes, but this has nothing to do with a CdRom: if you own the installation Cd of an operating system (or an ISO image) and need to install or test on that Pc without reader, this system turns to be useful.
And I personally find easier to bring an USB stick with you instead of a Cd or Dvd.

USB U3 sticks emulate a CdRom + a disk unit, can I use one of those sticks ?

No, those sticks emulate only a 6 Mega Byte CdRom unit, you can (but in an unofficial way) mount an ISO image different from the original one, but 6 MegaByte is too few for an operating system. Maybe in a (near) future someone will discover a way to 'increase the flexibility' of U3 sticks, let's hope that some U3 producer decide to remove locks !

Is it possible to install the Operating System on to an external Hard Disk or USB stick ?

Linux can be installed without problems, Windows no: this possibility has been locked by Microsoft; it is not possible to install Windows onto USB, eSATA or FireWire units.
But someone has succeeded installing XP on external Hard Disks, see here (in italian) and here.

How to do

We first have to say that it is not always possible because an official technique does not exists, only some 'hacking' operations not officially supported by USB stick producers. And you can't technically do it with any stick.
kingston 1gb side 1, from flashboot.ru

Disassembled USB stick, images from www.flashboot.ru

The electronic part of an USB stick is made by a USB controller and by Flash memory.
Controller is the interface between the USB port and the memory, it practically is a microcontroller with dedicated hardware.
Some controller producer have put available the possibility to emulate a Floppy drive, a CdRom crive, create a password protected secret area.
Unfortunately these capabilites have not been appreciated and you only can find a few sticks with a secret area.
I believe that the possibility (from hardware producers) to loose money by selling less Cd/Dvd drives has take a big part in this !
Only a Japanese company (Hagiwara Sys-Com) has created the 'UDRW' standard (intended for embedded systems) see here and this is exactly what we are trying to do here.
The U3 USB sticks emulate a CdRom unit (having autorun.inf file and U3 system inside) but you can only re-flash the CdRom unit with a small 6 MegaByte ISO image only; (too few) here an interesting discussion about.

We have to thank the russian site flashboot.ru (it's in russian language, but can be ternaslated by google translation for instance) for have found a way to re-flash the controller in order to enable the CdRom unit mode. But you cna only do this with a few controllers (installed in some old sticks). On the russian site you can find a list with all the sticks that have been successfully re-flashed, including detailed instructions.

Below instructions for sticks with a Phison model PS2134 controller, grabbed as they arefrom here. I personally re-flashed 2 sticks, a 1 GByte Kingston Data Traveler II and a 4 GByte Apacer AH320. I have tested these 'flash CdRoms' by installing Linux Ubuntu, Windows XP Cds and Windows 7 Dvd (this one using the 4 Gbyte stick). In order to find out if a stick can be re-flashed by following the technique below described the first step is to test, by using an appropriate software, if the Phison controller is 'on board'. Download (always from the same russian site): the appropriate software (it's in english) ant it's just the utility suppliead by Phison to initialize and flash it own controllers.
before you go on be aware that there is no warranty you will be able to succesfully flash a CdRom drive, in worst case you may totally destroy (become unrecoverable) the stick !.
1) Insert the stick in an USB port and make sure it has been recognized by Windows
2) Run F1_90_v196_00.exe (you get it from zip 'Phison_UP13UP14UP12_V1.96')
3) Press the 'Get Info.' button. Pay attantion, do not press any other button or you may erase the stick !.
4) If you get the message 'No drive found!' you can't go on, you stick can not be flashed by this software.
5) If you see all the stick technical information in the 'Test Information' window then you can try.
6) Go on by following the instructions written here.

The utility allows you to set the controller to one of the following configurations:
Mode 3 - standard mode. The standard stick: a read / write disk unit
Mode 4 - 2 sections. A Floppy unit and the standard disk unit (*)
Mode 7 - 2 sections. Two independent flash disk units
Mode 8 - 2 sections. Hidden, password protected section and a standard disk unit (*)
Mode 14 - 3 sections. Standard disk unit, HDD (not visible in Windows XP) and CD sections
Mode 21 - 2 sections. A CD (read only) section and the standard disk unit (*)
(*) : the unused flash memory part is left availabe to user as a second disk unit so you can use it as a standard USB stick

Stefano

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