CDMA and GSM--The General Difference:

CDMA and GSM are two different cell phone technologies that are the de facto standards chosen by wireless telephone carriers. The technical differences are too complex to discuss here; however, the basic difference is that GSM phones use Subscriber Information Modules called SIM cards, and CDMA phones use Preferred Roaming Lists called PRL files (see Glossary below). The easy way to tell the difference is that if your phone does NOT take a SIM card, then it is probably CDMA.

GSM carriers include:

--AT&T (formerly Cingular)

CDMA carriers include:

--Verizon Wireless
--Virgin Mobile

Some CDMA phones have a slot that looks similar to a SIM card slot. They are either hybrid phones that use BOTH technologies, OR the slot is what is known as an R-UIM card slot. An R-UIM card is a Removable User Identity Module also goes by the name CSIM or CDMA Subscriber Identity Module.

Visit for more information on these technologies.

Glossary (in no specific order):

ESN--Short for Electronic Serial Number. A serial number unique to each phone that identifies it to a specific carrier. Some carriers will not activate the ESN of phones that are from another carrier. Cricket typically does not restrict activating the phones of other carriers so long as it has not been reported lost or stolen. A lost or stolen phone is "blacklisted" or flagged in the company's database, and service representatives logged-in to a network computer system can identify these phones. The ESN consists of eight hexadecimal (hex) numbers and/or ten decimal numbers.

MEID--Short for Mobile Equipment Identifier--Similar to an ESN number, except with 14 hexadecimal numbers. Newer phones use MEID numbers. MEID numbers can be converted to ESN--the resulting numbers are called a "Pseudo ESN" or p-ESN.

OTASP--Short for Over The Air Service Programming. On most CDMA phones, programming the phone can be done "over the air" by dialing a special code, usually *228 or some variation. Sometimes abbreviated as OTA.

PRL or PRL File--Short for Preferred Roaming List--A small text file containing instructions for how a phone connects to a specific network's radio towers.

WAP--Short for Wireless Application Protocol--Technically speaking, WAP is a mobile framework for data exchange. However, this term is used colloquially to mean wireless Internet access or "mobile web".

MMS--Short for Multimedia Messaging Service--Also called Picture Mail--MMS allows subscribers to send pictures, sounds, and videos to one another with the same ease as text messaging. This is not to be confused with "Picture E-Mail" or "Rich E-Mail", which is the ability to send and receive e-mail using POP or IMAP protocols that can have embedded multimedia.

Brew--Allows you to download games and other applications to your phone. Different carriers have different names for Brew, and all Brew content is proprietary and locked to a single handset.

Java--Like Brew, but non-proprietary.

Mod or Modding--Short for "modifying"--To take the default "factory" settings and features and change, adapt, modify, add to, etc., hence modify. This also includes customizing the phone and its features, such as changing ("skinning") the phone's default theme (colors, fonts, etc.) or "tweaking" the User Interface (UI, i.e., menus, icons, graphics, etc.).

Hack--To make a phone do something it wasn't originally intended to do, especially if it violates rules, company policy, and even THE LAW!

Flash or Flashing--Technically, flashing refers to the overwriting or re-writing of the phone's firmware. The firmware is software in the phone that doesn't change when you turn it off, and it cannot be deleted unless it is overwritten, hence flashed. Colloquially speaking, flashing can also loosely mean making a phone from one carrier work on another carrier.

PST--Short for Phone Service Tool or Tools--Special software used by phone manufacturers to program their phones. Be advised that such software is considered "warez" (i.e., pirated/stolen licensed software) and the acquiring and trading of such software is technically illegal in most countries. You can and will be prosecuted if caught trading warez, and it is against the rules of this website and should not be discussed in the public forums.

"Monster File"/"Monster Pack", ROM, or "Kitchen"--System software that is needed to flash a phone.

MSL/SPC--Special six-digit codes needed to access service programming features on the phone. MSL stands for Master Subsidy Lock while SPC stands for Subsidy Programming Code. Some carriers like Sprint has a unique SPC for every ESN while others like Verizon use all zeros. You may be able to ask a customer service representative to give you this number, but be advised that they may refuse you or ask you why you need it.

Service Programming Menu--A special menu typically hidden from the primary User Interface that allows for "deep programming" of a phone. Typically, a special code is needed to access the service programming menu. Access to the service programming menu can be disabled in a phone's firmware.

MDN/MIN Pair--MDN stands for Mobile Device Number, while MIN stands for Mobile Identity Number. The MDN number is your standard 10-digit phone number including the area code. The MIN number starts with your area code, but it is important to remember that it can be otherwise totally different from your MDN number. In order for some phones to OTASP, they need a valid PRL and must be set-up with a valid MDN/MIN pair. You can ask a customer service representative and get your MIN number.

SID/NID Pair--Two important sets of numbers that determine what home and roaming towers your phone is allowed to connect to.

Useful Tools:

The following tools are FREE and 100% legal to use:

Required Skill Level: Moderate to Expert
Description: Use BitPim to interface with your CDMA handset to send and receive files such as ringtones, pictures, graphics, etc. In some cases, BitPim can also read contacts/address books, calendars/appointments/schedules, text messages, and other personal data.
URL: Welcome to BitPim

Required Skill Level: Beginner to Advanced
Description: Use Audacity convert and trim MP3's and other audio files to ringtones.
URL: Audacity: Free Audio Editor and Recorder

Nokia Multimedia Converter 2.0
Required Skill Level: Beginner to Moderate
Description: A simple tool that converts any audio or videos that your computer can play to audio and videos that will play on ANY handset that supports multimedia playback. Be advised: You must first sign-up to become a member of the Nokia Forums to gain access to download the program. They will email you a serial number to unlock the program during installation.
URL: Nokia Multimedia Converter 2.0

Required Skill Level: Moderate to Advanced
Description: A powerful multimedia converter that can convert almost every known audio and video format to audio and videos that will play back on ANY phone that supports multimedia playback.

Useful Links:

The following is a list of useful links to other websites that deal more specifically with modifying, repairing, and flashing mobile phones:

Howard Forums (a.k.a. HoFo)
Required Skill Level: Beginner to Expert
Description: Howard Forums is a good starting place for beginners, featuring tutorials from basic to advanced. The community is very active and busy with contributors, and the forums are broken-down into logical sections for carriers and manufacturers as well as various subgroups therein. Be advised that the trading and discussion of warez and other illegal activity on Howard Forums will more than likely get you permanently banned.
URL: HowardForums: Your Mobile Phone Community & Resource

My Basic Step-by-Step Cricket Phone Flashing Guide on Howard Forums

Required Skill Level: Experienced to Expert
Description: Mobile-Files is not a place for beginners to tread. Most topics assume you at least know the basics of flashing a phone, so do not expect any special help or attention if you are a beginner.
URL: Use Google to search. My apologies for the inconvenience, but this site is also the host of illegal warez links. Be advised that the trading of warez is considered illegal. Download them at your own risk.

Hack the RAZR
Required Skill Level: Moderate to Advanced
Description: Hack the RAZR is a Motorola fan site that focuses on modding Motorola 4LTR series handsets including the RAZR and KRZR.
URL: Use Google to search. My apologies for the inconvenience, but this site is also the host of illegal warez links. Be advised that the trading of warez is considered illegal. Download them at your own risk.

Moto Modders
Required Skill Level: Moderate to Advanced
Description: Another Motorola-only forum similar to Hack the RAZR.
URL: Use Google to search. My apologies for the inconvenience, but this site is also the host of illegal warez links. Be advised that the trading of warez is considered illegal. Download them at your own risk.

Cricket FAQ:

Q: What Mobile Technology Does Cricket Use?
A: Cricket and Jump are CDMA carriers. Some phones like the Nokia 6265i feature an R-UIM slot that looks like a GSM slot.

Q: Can I flash my phone to Cricket?
A: If your phone uses CDMA, chances are you can. Cricket accepts the ESN's of handsets from other carriers. There are a few exceptions, however, such as if the phone is reported lost, stolen, or otherwise blacklisted. Give the phone's ESN or MEID to a customer service representative and ask if it can be activated first. MEID numbers may need to be converted first to p-ESN (see Glossary above).

Q: How can I get ringtones on my phone?
A: Find the ringtone you like or use a tool like Audacity to create your own. If you are on a windows computer, find the folder settings and set change those settings to allow you to see the file extension of known file types. Change the file extension of the ringtone to .MID. Then e-mail the file to

*NOTE: If you get the message on your phone but the file is not there, try a different e-mail account.

Q: How can I get free games on my phone?
A: Unless your phone supports Java, be advised that acquiring Brew games and applications without paying for them is ILLEGAL, and the process for doing so involves understanding how to manipulate the phone's file system. Find a solution at your own risk. Furthermore, Brew games and applications are encrypted and cannot be shared between handsets without illegal modifications to the files or phone.

Q: How do I get files from my computer to my phone and from my phone to my computer?
A: Start by following the instruction guide that came with your phone. You can also visit the the support section of your carrier and also the manufacturer's website. If neither of those methods help then you may consider consulting an expert.

Q: How do I get my MSL/SPC code?
A: Cricket uses a code called a Secondary Subsidy Lock code which unique for every ESN. Contact a customer service representative and ask them what your Secondary Sublock Code is. If they ask why you need it, tell them that the phone is locked and you are stuck at a menu asking for the Secondary Sublock code.

Q: My phone isn't working correctly--what can I do?
A: Start by contacting customer service and have them reset and refresh all the services on your account. If this doesn't help, then visit the support section of Cricket's website.