Atari 2600 with composite mod

Started by davyk, October 13, 2019, 18:00:24 PM

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davyk

Have had a US 2600 for a few years now.

I bought it originally in the mistaken belief I could use it with my CRT in the UK with an RF connection. My plan was to use it with my Harmony cart loaded with a full ROM set and then make a small collection of CIB copies of my favourites.

It's a 4 switch woody and when it arrived it wasn't in as nice a condition as described. It's OK - just not great. The switches were pretty seized up. The difficulty switches at the back were jammed - got one working and one snapped off. I can still adjust it with a screwdriver but it needs replaced. Its the P2 switch so will be rarely used - but still - I was pretty pissed off.

I complained on eBay and I got a refund to almost the full value.

So when I realised the UK TV tuners wouldn't pick it up I got it modded for composite. Bought a kit online and got a local electronics repair shop to do the mod.

Got that done and got a really nice clean picture - but - only in b&w.  The instructions with the kit stated there was a colour pot to adjust but it didn't seem to make any difference.

Bought a composite NTSC - PAL converter. Didn't work.

Tried it with several TVs , modern - even a projector - nothing. Still black and white.

So I put it away. The idea was to make it a project. Learn to solder - replace the diff switch and maybe recap it if that would sort the colour problem.

Lay for a 3-4 years.

Recently got a couple of "new" CRTs after my old one died. Thought maybe I'd try again.

Rigged it up - still b&w.

Opened it up and tweaked the colour pot again - and - colour!!!!!!!

Delighted.

But there is some interference on the image - diagonal stripes. Seems to be affected by sounds too. It's not a huge deal - is more noticable on certain games than others. Still would likeit sorted.

After some poking around on forums - it seems to be an interference thing - poor shielding on cables - and some power supplies can cause it.

The power supply is pretty old and the cables I'm using are cheap so I'm going to try that out.



I also have a 6 switch woody PAL unit with an RF connection that gives me a sweet image on my CRT. I have a pile of PAL60 ROMs of my favourite games on the Harmony so I always have that as a backup.

If I sort the interference out I may consider replacing the diff switch.

Just thought I'd post here and update from time to time.

May start posting more about some hidden gems I find in the huge NTSC ROM archive I have.  :)




TrekMD

Nice. Cool to see that the system is working for you and in full color!  Be sure to check out this game that has just become available as a binary:


The link to the binary is in the comments for the video. 

Going to the final frontier, gaming...


davyk

#2
Was just reading that thread over at Atariage!!!  :)

It does look good. It seems the cart used a weird bit of hardware for the extra ROM on the cart which made it harder to dump that usual.


Checking the 2600 again. The guy who did the mod has the audio and video leads together tightly. No doubt to keep the wires secure from harm. I suspect the audio is interfering with the video.  They are very fine wires.

I can't unwind them without disconnecting one of them. I do have a soldering iron but I've never used one. Would probably be a easy thing to do though - just disconnecting it from the terminal, unwinding and then resoldering it.

The interference changes when I twiddle with the wires so I'm pretty sure it's what is causing it.


TrekMD

Hopefully you can solve the problem with the interference so you can finally enjoy the system and its games!

Going to the final frontier, gaming...


davyk


yeah.

Of course I have my PAL one - but NTSC games play with the wrong colours. I have a pile of PAL60 ROMs too which means I can play optimised PAL games but I'd like to be able to sample the entire NTSC library as intended.