How does a MOD CHIP work? 


Have you ever wondered exactly what does a MOD Chip do in your Playstation?  Well I have!  In fact I wondered about this long before I even owned a Playstation.  I might even go as far as to say that it's the real reason I ever got a Playstation in the first place.  (To hell with the games, I wanna see inside!)

3 Years later, I now install MOD Chips part time, and there is nothing mysterious about it anymore.  I have been able to fully integrate the MOD Chip (and color correction) into every single model (SCPH 10XX to 90XX) successfully.  Thanks to my many friends who have let me "operate" on their consoles over the years, I am glad to say I have not managed to kill anyone's Playstation.  (Although I have come pretty close to killing my own :)...  I have had several years experience with micro-soldering, and would NOT recommend attempting this modification unless you feel VERY confident in your ablity to work with surface-mount components.  You can VERY easily PERMANENTLY damage the Playstation if you fuck up in even the slightest possible way!  (You have been warned...)

I can now do what was a 2 hour modification in about 20mins.  I have previously worked as an electronic technitian, and my workmanship is totally professional all the time.  The Multimode MOD Chips that I use are without a doubt the most superiour and highest quality chip available.  (Or I wouldn't install it in my OWN Playstation.)   And YES,.. I am the ONLY licenced dealer of the Multimode Chip in South Africa.

This page is intended to explain (in the simplest terms possible) exactly what the MOD Chip does and why it does it.

If you are looking for detailed technical information, then I suggest that you email me instead, and I will try to address those specific issues if I am able to.

Before we get started, a quick word on possibly the biggest misconception regarding MOD Chips:                                

A "MOD Chip" is not an electronic component on it's own!  The "Chip" can be purchased from any electronic's store, but the chip is BLANK!  ie, It's like a new hard drive,  fully functional, but can't do ANYTHING until software is installed on it.  In the MOD Chip's case, an IC (Integrated Circuit) Programmer is required to program the actual "MOD Chip Software" onto the chip.  This "software" or "code" is what differentiates MOD Chips from eachother.  If we use the Hard Drive example again, it would mean that the drive is only as effective as the software being run on it.  

A blank chip (usually a PIC12C508 or 9) on it's own is USELESS!  The CODE that is PROGRAMMED to the chip is everything!!!

There are 3 main sections to understand:

1.  ZONE Codes, what are they?

2.  How the MOD Chip defeats ZONE Coding.

3.  Stealth/Multimode/Phantom etc vs Standard MOD Chips.

4.  Color correction, ie NTSC vs PAL.

Let's Begin:



Firstly, let me explain why you can't play American or Japanese games on a European Playstation:

There are  3 "Zones" for Playstations.  They are:  Europe, America and Japan.  As you should already know, Europe uses the PAL standard, America and Japan use the NTSC standard.  This presents the first problem, ie NTSC/PAL compatibility.

The games are restricted to their native zone.  Ie,  When a Playstation game is created at Sony's factory the CD is created with a "ZONE code" on the CD.  This code is either SCEE (for Europe), SCEA (for America) and (SCIE for Japan).

This is very important:  The ZONE CODE information CAN *NOT* be copied under ANY circumstances, by ANY commercially available CD Writer.  (Yes, only Sony's CD Manufacturing Plant can make CD's containing the ZONE code.)

When you copy a Playstation game, there is NOTHING YOU CAN DO to copy the ZONE information from the original CD.  Some CD-Writing software "CLAIM" to be able to make identical copies of originals.  This is true pertaining to data on the CD, NOT the ZONE information!  Let's be very very clear on this:  Your copied Playstation CD will be identical to the original in every single way, with the EXCEPTION of the ZONE code.

Now let me add that the ZONE code is not needed to "play the game".  It is only required for the Playstation to identify the CD.  It needs to know the CD's ZONE code so that it can determine if the game is from the same ZONE as the Playstation itself.

The Playstation Console itself has a ZONE code also (SCEE, SCEA or SCIE), and this cannot be changed.  The CD Zone code of the inserted CD needs to MATCH the Playstations ZONE code exactly in order for the Playstation to accept the CD and start he loading process so that you can play.

Now that you (hopefully) understand the ZONE codes, we can move on to how the mod chip defeats this.


How the MOD Chip defeats ZONE Coding:

Foreword:  ZONE coding is a pretty good way to prevent games from other zones to be played in any specific console.  The reasons this was done is basically due to the fact that games are released in different zones at different times.  Generally games are released in Japan first, America second and Europe are last in line.  Sony don't want games from Japan (for example) to be playable on European console's long before their release in Europe, otherwise when the game is released for that zone, the sales will be impacted upon as the game is already "old news".  (There are numerous other reasons for this restriction and whether or not it is justifiable, but that is another topic entirely.)  

When you insert your CD into the Playstation, the first thing the Playstation does is examine the CD for ZONE Codes.  It then takes what it finds and compares it to the Playstations hard-coded ZONE code.  If they match, the games loads, if not,.. well.. it doesn't.

In the case of a copied game, the Playstation can not (and will not) find any ZONE code, therefore it fails the CD.

Let's assume you have a European Playstation (SCEE) and you're inserting a COPY of a Japanese Version (SCEI) game,.. the Playstation is EXPECTING to get SCEE ZONE code from the CD, but it finds nothing, so the CD fails even though the game data itself is fully intact and copied 100%.

All the MOD chip does is INTERCEPT the line that the ZONE code would travel along, and inject a constant "stream" of the correct ZONE code that the Playstation is expecting.  (SCEE in this example).  As soon as the Playstation checks to see what ZONE code is being received from the CD, it is supplied with the code it is expecting, because the MOD-Chip is constantly sending it.  The Playstation therefore believes that it's ZONE code requirement has been met, and proceeds to load the game.

This is all you need to know about what the MOD Chip actually does.  (Exactly where it injects and how are not relevant to understanding the operation of the MOD Chip.)  Now we can have a look at MOD Chip variants like Stealth/Phantom/Multimode/Ghost etc.


Stealth/Multimode/Phantom etc vs Standard MOD Chips:

There seems to be a lot of confusion regarding the different "types" of chips, so let's clear it all up right here:    There are a lot of dirrerent names, but they all work on the SAME principal, so the naming is not important.  As an example, we will use the name "Stealth", but we're referring to all of them.

Essentially there are only 2 types of MOD Chips,ie Those WITH Stealth and those WITHOUT Stealth.

To understand what the Stealth chip does, you need to fully understand all the above.  If you know how the Playstation looks for ZONE codes, and how the MOD Chip supplies them, then read on.  (Otherwise (re-)read above.)

Now that we know how to defeat the ZONE code check, another check was implimented (rather brilliant).  Since the MOD Chip is always sending a "stream" of ZONE codes in order to keep the ZONE Code check happy, it would be easy to simply check WHEN the zone codes are being sent.

In a totally UN-modified Playstation, the ZONE code is only sent in one "burst" when the Playstation is looking for it, then it STOPS!

As the MOD Chip is constantly sending a "stream" of ZONE codes, the game can be written that at a certain point during the startup, it can check if the ZONE codes are still being sent.  If they ARE, then they know there is a MOD chip present, and can fail the CD.  

This is the process of a "Normal" MOD Chip (WITHOUT Stealth):  You insert the CD, the Playstation checks the CD.  The MOD chip sends a constant stream of the correct ZONE codes.  The Playstation looks at what is being received, and because it will ALWAYS match it's internal ZONE code, it lets the game load and you can play.

This is the process of a "Stealth etc" MOD Chip (WITH Stealth):  You insert the CD, the Playstation checks the CD.  The MOD chip sends a stream of ZONE codes.  The Playstation looks to see what is being received from the CD and as it is what the Playstaion is expecting, it lets the CD load.  Before the game loads however, the software on the CD, looks AGAIN at the line that is used for ZONE codes.  If it see's ANY codes STILL being sent, it fails the CD.  The Stealth chip however is designed that after a certain time, (or a signal triggered by the Playstaion), it STOP's sending the ZONE codes.  The game then see's nothing on the ZONE code line, so it passes the 2nd check and the game loads.

There are numerous methods used to tell the Stealth Chip to STOP sending codes.  Originally a simple time delay was used (approx 2.3sec).  This turned out NOT to be very effective with all games, as the exact timing of when the game does it's second check varies from game to game.  MOD Detection requires different timing on different games.  So an internal signal from the Playstation itself (usually a trigger from the position of the laser's head) is used to tell the Stealth Chip:  "Okay, stop sending codes now!"  Before the second check can be made on the ZONE code line.

Note:  A few of these "Stealth" chips are still based on the "time delay" trigger.  However, in an attempt to keep up with all the games with different timing requirements, a method was developed to allow the user to VARY the time delay himself.  This was done by the following process:  By default, the chip will use a 2 second delay (for example).  If you hold down the RESET button, Power ON the Playstation and wait 3 seconds, then RELEASE the RESET button, this will step the timing up to 2.1seconds.  Holding reset at startup for 6 seconds will give you 2.2 seconds delay, 9 seconds for 2.3 seconds etc etc.. you get the idea.  Simply turning the Playstation OFF then ON again (without holding the reset button) will reset the timing to it's default 2 second delay setting.  You could therefore vary the timing, until the Playstation accepted the disk.

This entire line of MOD Chips was developed due to the ever increasing amount of games that use ANTI-MOD technology.  (ie a method used by the GAME to determine if a MOD Chip is installed in your Playstation.)  Not all games use ANTI-MOD, in fact very VERY few games do.  Of which 90% are Japanese versions only!  More info on games supporting ANTI-MOD can be found here.

Okay, so now we understand how the MOD Chip works,.. how does color fit into it all?  I have a MOD Chip in my Playstation, but some of my games are now black and white?  What's up?  Do I need a color chip now to fix this?


Color correction, ie NTSC vs PAL:

A Color MODule as shown here is only required for older model Playstations, ie model numbers from the SCPH 10XX and SCPH 5XXX series.  Later models can be forced into color mode's without the need for external components!

Okay,.. what we need to make clear here is that defeating ZONE code restrictions and color correction are two TOTALLY different modifications, and are NOT related.  Statements like "color MOD chip" are very misleading!  The MOD Chip has *NOTHING* to do with whether or not your picture will be black and white or color.

I am going to try to make this as simple as possible, as this is a rather complex technical issue, but it can be summarized like this:

PAL is the standard used in Europe, and NTSC is the standard used in Japan and America. (Reasons for this are too complex to discuss here.)  A game released in Japan (for example) is INTENDED to be played on a NTSC system.

NTSC and PAL are displayed differently on a TV.  The Refresh rate is different, the horizontal lines displayed are different, etc.  (More detailed information on this can be found on this web site.)  Games designed to output to a NTSC system will appear in black and white on a PAL system.  In some cases, the picture will just "roll" on the screen and in rare cases, four instances of the picture will appear on the screen.  This is a result of the TV not being tolerant of the differences in output signal being received from the Playstation.

This can be resolved by making a modification to the Playstation that will "lock" it's output to a NTSC or PAL frequency.  (On older models of the Playstation, this modification is not possible, so a small module needs to be constructed that will perform this task (10XX and 5XXX models). [see picture above]

NOTE:  If your TV is not capable of tolerating the line output difference, you may *STILL* get a "rolling" picture, color MODule or no color MODULE.  If this happens, the problem is the *TV*,.. not (and I repeat NOT) the Playstation!!  The good news is that about 95% of TV's used today are tolerant of the line difference, they will simply "stretch" or "squeeze" the image to fit on the screen.  The problem is with OLD TV's.  (Mostly from the Pre-Remote Control/On Screen Display Era.)  If you have one of these older TV's, you MAY encounter this problem to which there is no "fix". You will need to (and probably should anyway) buy a new (more modern) TV set.

Most people who install MOD Chips do the color correction modification at the same time that they install the MOD chip.  This contributes greatly to the misconception that color correction and ZONE code defeating are one and the same,.. which of course they are not!

As I mentioned, the NTSC/PAL incompatibilities are a potentially long and involved discussion, and what I have outlined here is very very simplified explanation that is only significant in understanding the overall workings of the MOD Chip,  which is after all what this tutorial is really about... :)

Final Word:   As I mentioned before, this is an "overall" explanation of the MOD Chip.  If you understand all this, then you understand what's going on in your Playstation every time you turn it on with that "backup" inserted and ready to play.

I don't claim to be the world's biggest expert on MOD Chips, but if you do have a question regarding something that is not covered here, feel free to email me and I will try to clear it up for you if I can. 

Oh!, and make sure if you're going to get a chip installed, you let me do it...   :)

A naked ape, in the human zoo.  You amaze me with the things you do...   - Skyclad


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