View Full Version : Strange?

09-09-2000, 09:46 AM
recently i bought a brand new unused NEO*GEO
with the game Magician Lord included. I payed 300 SEK (30$)which i consider a good deal =). Anyway the problem i have is that when i play, the top and bottom area of the screen displays the wrong grahpics (pieces of ladders hanging in the air, eltas hat, the word continue, etc..). I have a pal system and i use the antenna cable (the RGB was not included). I have changed TV sets but it's no good.
Does anyone know anything about this ?

Thanks in advance.

Neo Bomber Man
09-09-2000, 01:01 PM
Is this a cartridge or CD system?

If it's cart (which I'm assuming) then you could try cleaning the connectors on the game itself, which often solves graphical & sound glitches. Cleaning the system's connectors can be, though isin't necessarily, a bit difficult however. Depends what tools you have to work with.

If in fact you've got a CD doing that, then I would guess the CD is going bad & should probably be replaced. Not an expert with CD systems so take my suggestion for what it's worth.

09-09-2000, 04:35 PM
It is indeed a cart system. But it has never been used before so the connectors on both the cart and system are spotless. But i'll try it anyway. What kind of tools would i need to clean the cart?.


09-09-2000, 04:45 PM
Do you have any other games to test the sysyetm with? I think that cleaning is needed.

By the way, Greetings from Stockholm/Sweden.


09-09-2000, 05:15 PM
No i dont have any other games to test with(i've been searching like a maniac but to no avail).

Hey Robi15, do you know any swedish neo sources !!?.


Master Terry Bogard
09-09-2000, 10:33 PM
Hi. I am kind of new in this, but I think everyone is right. Maybe the contact or the system needs cleaning? I think some one suggested cleaning w/ an eraser. It was in this forum, under cleaning or what not.

Neo Bomber Man
09-10-2000, 02:49 AM
Let's see if I can get this up before Netscape crashes again...

There are a few ways in which to clean the connectors. Here is the simplest of which I know.

1)Get some Q-tips. Lightly wet the end of it (do not soak it or anything like that). Rub it along a soap bar to get it a bit soapy. Again, make sure it's not too wet. Next, rub it back and forth along the connectors. (you have to press really hard) I did this to some old Nintendo games & got a load of muck off the connectors. They worked like new afterwards.

2)Repeat this process, only this time leave out the soap.

3)Repeat again, this time with a dry one. Get something else to dry the connectors & bottom of the cart with. Do one connector at a time.

There are chemical solutions that will also do the job, and presumably a better one, but I can never recall which chemicals to mix, nor in what quantities. So once in a while a game or two gets cleaned for me by someone else.

The only thing you ought to be wary of, is don't rub a soaking wet q-tip on the connectors. You don't want to risk excess water running into the cart itself if you're not careful. Otherwise, this method has proven itself to work with cartridges.

Cleaning the system's connectors is another matter altogether, and I'm not the one to recommend on how to do that.

Bonne chance.

09-10-2000, 09:42 AM
Easy way to clean your carts:
Use a #2 pencil. The ones with the red erasor. Clean the contacts with the erasor.
It does a great job. And no water to worry about.
http://grador.radix.net/%7Ekws/trey/nickslink.gif (http://nickthfury.cjb.net/)

09-10-2000, 10:28 AM
Sourses in Sweden:
Gulatidningen (a magazine where they sell second hand stuff) är den bästa.

and TV' spelsbörsen is Stockholm kan ha ett och annat.( a shop in Stockholm)

And the best sourse is Ebay. I have purchased many carts from there! I recommend it! Any more questions? Feel free to email me! http://www.neo-geo.com/ubb/smile.gif


09-10-2000, 07:17 PM
Solution !!!

Its really simple u running the neo-geo on 50 Hz. Most all Pal mashines run on 50 Hz. because of the pal output u got a smaller Piture on TV. So there are some black stripes on top and bottom. In case of Magican Lord u see the building picture because of the smaller TV Picture. Do not worry its normal .... other games mostly dont have this so ML is uniqe with that....
U schould thinking about a 60 Hz Mod the Game runs 17 % faster and u will have the full TV Sreen.

09-11-2000, 02:02 AM
The 60Hz mod is the one where you cut the PAL1 jumper right?. Is there any documentation on this ?


09-19-2000, 10:36 PM
Sorry for the late reply, but I missed the post somehow.

Anyway cutting (but NOT removing) the pal 1 jumper will result in a 60htz signal, it depends on your board type though as to which colour frequency it is at.

With an AES3-5 board you will have a 60 htz pal signal. If you live in europe as you do, this is fine as your tv (assuming it isn't a real fossil) will sync up fine =) If you want a ntsc colour signal, you'll have to replace the frequency crystal, but this really isn't neccessary for you =)

With a AES3-6 board, you will have a 60htz ntsc signal by just cutting this jumper, as it has a ntsc colour frequency crystal in it already.. Assuming again that your tv isn't a fossil, it'll still have no probs =)

There are other board revisions, those were just an example..


09-20-2000, 12:21 AM
While designing my RGB-NTSC converter board, I learned a lot about how NTSC/PAL encoding works...

Converting your home systems from PAL to NTSC is not quite as simple as you guys make it sound. For NTSC, the encoding chip requires a 14.318180Mhz clock (not 60Hz). For PAL encoding, a 17.734475Mhz clock is required. Depending on the type of system you have, you should see the appropriate clock oscillator located near the encoder chip (metal case with 4 pins).

I am not sure what type of encoder chip is intalled on the home systems, but most encoder chips can perform both NTSC and PAL encoding. The two encoding schemes are significantly different and you can not simply just switch the clock frequencies, you must tell the chip what type of encoding you want. Usually this is selected by a digital input on the chip (eg. high for NTSC or low for PAL).

Once you have the proper clock frequency and have the chip working in the right encoding mode (if it even supports that mode), you need to change the filter circuit. Without the proper filter circuit, your composite output will look like crap with poor color (s-video will be unafffected). Usually this just consists of changing a capacitor and/or inductor depending on the type of filter.

In conclusion, it is pretty complicated. I doubt it's as simple as cutting a resistor.

[This message has been edited by SmokeYa (edited September 19, 2000).]

09-20-2000, 05:40 AM
Smokeya: I'm sorry but in this case it IS a simple as I and others make it out to be.
As I have switched many systems and am currently switching one right now (Vinevessel's). Incidentally it's a jumper, not a resistor, a little bit of differrence.

Check out a discussion Jeff and I had concerning this under a post made by vinevessel here for more info if interested.. One more thing though, the simplicity of changing signal frequencies is a hall mark of consoles using a sony cxa chip.. Though the megadrive IS a pain in the ass in some ways...

Anyone got a scan of a aes pcb online to illustrate for smokeya?


09-20-2000, 08:47 AM
NTSC requires a 3.579545 MHz Crystal, PAL is 4.??? - I'd have to double check on that one. The Neo uses crystals (HC49/U casing), not the 4 prong oscillators.

The home system uses a Sony CXA1145 chip (the CD system uses a CXA1165). These chips have an NTSC/PAL select (voltage setting). The Neo boards are already built with the necessary circuitry and have jumpers for this setting.

Just out of curiosity, What chip did you use for your encoder? I would suggest checking out the Analog AD722, AD724, or AD725 - nice for RGB->NTSC, works well for arcade boards.

This place, www.jrok.com, has a nice RGB-NTSC converter which functions very well I'm told.


09-20-2000, 10:02 AM
> NTSC requires a 3.579545 MHz Crystal, PAL
> is 4.??? - I'd have to double check on
> that one.

Technically we are both correct. It is true the encoded output is at 3.579545MHz for NTSC, but I was talking about the clock input for the encoder chip. All the encoder chips I have looked at require a 4x clock (4 x 3.579545MHz = 14.318180Mhz) in order to do the encoding (including the AD725 that you mentioned). I guess it is possible that the Sony CXA1145s use a 1x clock (I would have to look at the data sheet), but most encoding processes in general require a faster clock input for encoding. I didn't state that in my first post because I didn't want to get so technical and long winded http://www.neo-geo.com/ubb/smile.gif

> The Neo uses crystals (HC49/U casing), not > the 4 prong oscillators.

Yea it can be done either way. I just assumed they used a clock ocsillator. I don't have a home system anymore, but I thought I remembered a clock oscillator on my Neogeo CD. A 2-pin oscillator is just a subcomponent of a 4-pin clock oscillator. A 2-pin oscillator requires extra external circuitry to provide a clock output, where a clock oscillator does not.

> The Neo boards are already built with the
> necessary circuitry and have jumpers for
> this setting.

The jumpers probably control the encoding mode, but I'm pretty sure you still have to change the oscillator. I doubt they installed both NTSC and PAL oscillators on the board.

Hey I'm glad I have someone to talk technical jargon with http://www.neo-geo.com/ubb/wink.gif

09-20-2000, 11:08 AM

Sorry I didn't mean to offend you, I just was trying to provide some insight to you guys on how the encoding circuits work. I made my post because a lot of the stuff you stated in you last post didn't make much sense to me, such as "60 Hz ntsc signals" and "ntsc colour frequency crystal".

If you have done conversions before and are happy with the image results, then that is fine. I was just trying to share a little knowledge with you guys to help you improve your results. I remember in some previous posts that you were confused on the subject. Here is a quote from you:

> If you switch the crystal (done this in a
> couple of neo geo's just to test it) to an
> ntsc frequency crystal you actually get a
> detoriation in the picture quality (from
> RF and composite, no s-video for me. Only
> rgb). The jumper you speak off is set on
> ntsc and not pal in everyone of the few
> neo geo's I've opened.

and also...

> When I've tapped the signal dirrectly from
> the cxa chip for composite video without
> going through the caps it doesn't suffer
> from the distortion, though naturally the
> colour spectrum is a little bright shall > we say ;-)

09-20-2000, 09:15 PM
Smokeya : None taken at all =) I should have made a more indepth post in response, but unfortunately I was a little bit strapped for time http://www.neo-geo.com/ubb/frown.gif So I might have sounded a little more abrupt that I should have..

When I was refferring to the 60hz I was not reffering to the signal frequency onboard, but the actual signal that the tv displays. 50hz (60 ntsc tv) being the display frequency of a standard pal signal on a tv..

Try this url, it's a of the sony cxa1645 encoder, may interest you..

I wouldn't call those posts confussion, just illustrating a few points. There are just differrent revisions of the board that achieve the same process in differrent manners.. Also just when you think you've got something down pat, along comes another type of pcb that throws a spanner in the works. The AES3-6 board I mentioned earlier is vinevessels neo, it did produce a PAL signal, had a 3.5 ect mhz crystal and a jap bios. Wierd =)

Anyway I've only really touched this chip concerning rgb--> composite encoding, no other meathod. So any input from you is great and I'd love to hear more =)