The time has come.... (PAL Modding guide)

Includes Atari 2600, Nintendo 8-bit, Sega Master System, MSX and more!

Moderator:Moderators

Post Reply
houseguest
Posts:8
Joined:Sat Aug 22, 2009 5:14 am
The time has come.... (PAL Modding guide)

Post by houseguest » Sat Aug 22, 2009 5:56 am

OK. So I've been lurking around these boards for... well... years. Every now and then I toy with the idea of making a portable Atari, and then convince myself it's beyond my capabilities! Mainly due to two factors: -

1. I can't solder to save my life.
2. I live in the UK and I see that the PAL 2600 is quite different to the NTSC one, and every guide I can find mentions the NTSC one only.

Anyway, about a month ago I was at my local car boot (Do you have these in America?) and there on a stall was a 2600 Jr. So I figure, what the hell! LET'S GO FOR IT!

So I took the Jr apart, bought a ton of stuff from Maplin (UK version of Radio shack) and set to work. To my utter amazement, IT WORKED! That is to say, Ben's original video mod worked, (new one didn't) and I could power it from batteries. Now the only problem with this is that the Jr... well..... sucks! It's made of the cheapest components and no matter what I did, I couldn't get a satisfactory picture on either my main telly, or the portable one that I intend to use. On games like SW Death star battle, the enemies were virtually invisible and try as I might, I could not get the water in Pitfall to go blue, without the other colours on the screen turning into a garish mess!

So I figured if I was going to do this, I was going to do it right! I ventured onto ebay and looked for a 4 switch. Now here comes the first international hurdle! In the UK we only got 2 models of 2600. (Not including the various Jr models) We got the 6 switch woodie and the 4 switch vader. I honestly didn’t even know a 4 switch woodie existed until I saw them on ebay US. Anyway, woodies are common as muck, vaders come up far les often, and when they do, they’re not cheap. Still, after a short time I found a one listed as faulty and took a chance that I could get it working again. Sure enough, it arrived dead. I connected batteries to it in the hope that it was power… still dead. So I did the video mod on it and…..BINGO! I guess the RF box must be fried or something coz it sprang into life, and the colours are bang on! (Well almost, but more on that later!)

So given the fact that there is naff all info on modding a PAL 2600 on the internet. And the fact that Radio Shack part numbers aren’t much use to us here in Blighty, I’ve decided to document my build in the hope that it will help others in PAL territories avoid some of the problems I’ve had. (Like 2 orders to Maplin for the wrong bits!) I intend to take pictures of every step of this build and hopefully when it’s finished, others will see that actually, it ain’t that hard!

The piccies attached below display the PAL 2600 Vader motherboard, testing it to see if it works and hacking it down to size. International hurdle number 2! The PAL can’t be hacked into a 4”x4” square as it has this daft protrusion on the side. Something I hope to relocate as I go.

Now for the bit where I ask for help! (This will be a recurring theme! ;-)) Just got one question so far. The picture below of it running Frostbite (one of my faves!) was taken when I’d only just done the mod. As you can see the colours need a bit of tweeking but it’s not far off. So my question is…. Where have the score and timer gone?!?!?! If you play the game you can see movement in the blue, but no amount of altering the pots will make the score appear! All other games tested so far though, work perfectly! Any ideas?

Any other comments or suggestions are welcome. I’ll hopefully be updating this soon!

Rik,
Attachments
CAM_0022upload.JPG
Old video mod and battery powered. Don't worry, I'll document how to do this on a PAL machine when I actually build it.
CAM_0022upload.JPG (135.03KiB)Viewed 9956 times
CAM_0021upload.JPG
Don't look! She's NAKEDER!!!
CAM_0021upload.JPG (120.06KiB)Viewed 9956 times
CAM_0018upload.JPG
Don't look! She's NAKED!
CAM_0018upload.JPG (75.1KiB)Viewed 9956 times

houseguest
Posts:8
Joined:Sat Aug 22, 2009 5:14 am

Re: The time has come.... (PAL Modding guide)

Post by houseguest » Sat Aug 22, 2009 5:58 am

More Pics
Attachments
CAM_0024upload.JPG
Frostbite! Colours are out at this stage and where's the score/time gone?!?!
CAM_0024upload.JPG (60.31KiB)Viewed 9955 times
CAM_0030upload.JPG
Splitter!
CAM_0030upload.JPG (133.71KiB)Viewed 9955 times
CAM_0031upload.JPG
The 4"x4andabit" shape!
CAM_0031upload.JPG (132.13KiB)Viewed 9955 times

User avatar
themadhacker
Senior Member
Posts:2670
Joined:Wed Aug 06, 2008 7:53 pm
Location:ohio

Re: The time has come.... (PAL Modding guide)

Post by themadhacker » Sat Aug 22, 2009 8:48 am

nice to see aomebody working on an atari. BTW, I think the reason the video mod on the jr looked like crap was because the old av mod was crap.
rest in peace, Ronnie James Dio! \m/

houseguest
Posts:8
Joined:Sat Aug 22, 2009 5:14 am

Re: The time has come.... (PAL Modding guide)

Post by houseguest » Sat Aug 22, 2009 10:18 am

Thanks for the note mad hacker! I've always loved the Atari ever since my older Brother got one christmas 83! So it had to be my first!

Got another question for you guys. I've found this - http://portablesofdoom.org/images/2600_pal_back.jpg" onclick="window.open(this.href);return false; - which will be massively helpful! Or it would if I knew what each letter meant! I think they're based on the rundown from Ben's book but as I can't get hold of a copy does anyone have the letters list and could upolad it?

I can work out most of the bits, but I'm a bit stuck at the moment on where to connect the new +5v power in! I think it's Y but don't wanna fry the board in the first few moves!

Cheers,

Rik,

houseguest
Posts:8
Joined:Sat Aug 22, 2009 5:14 am

Re: The time has come.... (PAL Modding guide)

Post by houseguest » Sat Aug 22, 2009 10:24 am

Evil Nod you beat me to it by 5 minutes! :-D Thank you very much though! Do you know what each letter means? I know the connections to the TIA and RIOT chips and have worked out that W is where the IC unit needs to go to. I'm also figuring Z is ground and I know Q is Audio and X is Chroma. So it's really just O, P, Y, I, J, K and L I need!

EDIT Would O and P be left and right difficulty? Wouldn't that come from the RIOT Chip? Which would make I and J P1 and P2 fire buttons, and K and L Paddle 1 and Paddle 2!

So that MUST mean that Y is +5v? Right?

Cheers,

Rik,
Last edited by houseguest on Sat Aug 22, 2009 10:30 am, edited 1 time in total.

User avatar
themadhacker
Senior Member
Posts:2670
Joined:Wed Aug 06, 2008 7:53 pm
Location:ohio

Re: The time has come.... (PAL Modding guide)

Post by themadhacker » Sat Aug 22, 2009 10:28 am

A. P2 joystick up
B. p2 joystick down
c. P2 joystick left/ paddle4 trigger
d. p2joystick right/ paddle 3 trigger
e. p1 stick up
f. p1 stick down
g. p1 stick left/paddle2 trigger
h. p1 stick right/ paddle 1 trigger
I. p2 trigger
j. p1 trigger
k. paddle 2
l. paddle 1
m. select
n. reset
o. p2 difficulty (open=expert/ closed=novice)
p. p1 difficulty
q. audio out
r. video circuit to 1k potentiometer
s video circuit to 22-ohm resistor
t video to 1k potentiometer
u video circuit sync
v color adjust
w to 8-pin chip
x. video circuit chroma
y. 5 volts in
z. ground.
rest in peace, Ronnie James Dio! \m/

houseguest
Posts:8
Joined:Sat Aug 22, 2009 5:14 am

Re: The time has come.... (PAL Modding guide)

Post by houseguest » Sat Aug 22, 2009 10:32 am

Thanks again Mad Hacker! Do way would i have risked trying this on my shaky logic!

Here I go again! Wish me luck!

Rik,

houseguest
Posts:8
Joined:Sat Aug 22, 2009 5:14 am

Re: The time has come.... (PAL Modding guide)

Post by houseguest » Sat Aug 22, 2009 1:00 pm

Well... it took me about two hours, and that included getting the Dremel back out of the shed and cutting off the IC section, (Seems I'm as rubbish at desoldering as I am at soldering!!!) and also watching some of Smokey and the Bandit which was on ITV but.......

IT LIVES!!!!!!!!!!!!!!!!!!!!!!! Bwa ha hah har!!!!

I took step by step photos so will upload them soon, but in the meanwhile check out the ones below!

Next jobs, to tidy it all up, sort out the colour, hook it up to my portable telly and build a case! Not much then! :-)

Massive thanks to Mad Hacker and Evil Nod. The key to a PAL portable is in that picture and alphabet list.

More updates to come soon! I have an awesome idea for the case!

Rik,
Attachments
CAM_0043upload.JPG
Finished! Please let it work!!!
CAM_0043upload.JPG (139.42KiB)Viewed 9923 times
CAM_0047upload.JPG
With the Composite lead attached.
CAM_0047upload.JPG (152.45KiB)Viewed 9923 times
CAM_0050upload.JPG
Oh yes!!! More Frostbite! Dunno why the colours have degraded so much though. Maybe I will try the new mod again now that I have a 4 switch. (Or NO switch! As it is now!)
CAM_0050upload.JPG (60.49KiB)Viewed 9923 times

houseguest
Posts:8
Joined:Sat Aug 22, 2009 5:14 am

Re: The time has come.... (PAL Modding guide)

Post by houseguest » Tue Aug 25, 2009 3:12 am

Okay, so I'm preparing the controls at the moment and maybe I shouldnt be worrying about this yet but I can help but wonder why all the colours have messed up so badly since chopping down the board? Before chopping, they were almost bang on, post chopping they are garish and messed up. The colour tint pot taken from the atari board is wired up correctly but seems to have no effect at all anymore and the two pots on the video mod, one alters the contrast slightly at the very end and the other one just makes it black and white if you turn it down further than half way.

So my questions are: -

1. I have now resoldered the wires to the TIA chip a few times. Is it possible to damage the chip and cause this problem by overheating the chip?

2. Does it matter where the colour tint pot gets unregulated power from? Currently it's wired directly to the batteries.

3. If I attempt the new video mod, (though this one was working fine for me) is there an alternate transistor that could be used? Ben lists a 2N4401 which I cannot find in the UK. I have a 2N5551 and a 2N3904 to hand. Would either of those work?

Grateful for any and all help!

Rik,

JackTar
Posts:24
Joined:Sat Apr 28, 2007 1:53 am

Re: The time has come.... (PAL Modding guide)

Post by JackTar » Sun Nov 01, 2009 10:43 am

Have you considered this?

http://www.longhornengineer.com/Videomods/Videomods" onclick="window.open(this.href);return false;

User avatar
Rekarp
Portablizer Extraordinaire
Posts:2163
Joined:Thu Dec 28, 2006 1:52 am
PSN Username:Lnghrn_
Steam ID:rekarp
Location:Austin, Tx
Contact:

Re: The time has come.... (PAL Modding guide)

Post by Rekarp » Mon Nov 30, 2009 11:05 am

JackTar wrote:Have you considered this?

http://www.longhornengineer.com/Videomods/Videomods" onclick="window.open(this.href);return false;

Not tested for PAL yet but no reason it shouldn't work.
The wood master

Image

"I was under the impression Mac owners don't actually USE their machines, they just parade them around trying to evangelize the masses."

kiki77
Posts:4
Joined:Sat May 17, 2008 6:08 am
Location:Black Forest, Germany

Re: The time has come.... (PAL Modding guide)

Post by kiki77 » Mon Dec 06, 2010 5:24 pm

Can i have an instruction of your PAL video mod, please?

Post Reply