Atari 2600/7800 Composite MOD

Any 8bit repairs, images, cool things, upgrades etc.
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rubber_jonnie
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Re: Atari 2600/7800 Composite MOD

Post by rubber_jonnie » Fri Feb 23, 2018 3:48 pm

I've never taken my 2600 apart, so have no idea of how much space there is in it.
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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exxos
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Re: Atari 2600/7800 Composite MOD

Post by exxos » Fri Feb 23, 2018 7:09 pm

I thought I would post this here as I've been puzzling over this for the past few hours...

It seems the TIA chip has a different pinout for PAL & NTSC machines. This could be why when I tried my mod originally, it failed miserably as I could have been following a NTSC pinout for the TIA :roll:

It is also clear that the NTSC TIA chip also appears to have stereo audio output, and yet the PAL one does not..

TIA_PAL_NTSC.jpg
TIA_PAL_NTSC.jpg (49.54 KiB) Viewed 582 times
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

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rubber_jonnie
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Re: Atari 2600/7800 Composite MOD

Post by rubber_jonnie » Fri Feb 23, 2018 11:46 pm

Ok, they're quite a bit different :o
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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rubber_jonnie
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Re: Atari 2600/7800 Composite MOD

Post by rubber_jonnie » Wed Mar 07, 2018 9:42 am

Ok, so more info here, got the details of a mod for a 2600jr, which is a bit different.

http://blog.tynemouthsoftware.co.uk/201 ... o-mod.html
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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rubber_jonnie
Posts: 472
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Re: Atari 2600/7800 Composite MOD

Post by rubber_jonnie » Sun Mar 18, 2018 6:38 pm

rubber_jonnie wrote:
Wed Mar 07, 2018 9:42 am
Ok, so more info here, got the details of a mod for a 2600jr, which is a bit different.

http://blog.tynemouthsoftware.co.uk/201 ... o-mod.html
So, I had a crack at this over the weekend, and I've sort of got sound, but no video, however I think my cables are missing a ground somewhere along the line, as I added the cables slightly differently, so I will revisit and see if that fixes it.

Serves me right for diverting slightly and using cables instead of sockets. D'oh.

I'll report back.

EDIT: So I was right about the gound being an issue, now it's sorted, it's all working nicely. Picture is a lot better than via the modulator, though I have kept the parts in case I want to sell it on at a later date.

Need to look at the 7800 next.
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

atari030
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Joined: Mon Feb 12, 2018 12:43 pm

Re: Atari 2600/7800 Composite MOD

Post by atari030 » Mon Mar 19, 2018 9:13 am

Good stuff. I have a Jr I spannered playing with video mods a while back. Glad you did this as I needed some motivation to get on to it. I have a vader I put sockets on, wish I had used cables as I hat things that aren't reversible.

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rubber_jonnie
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Re: Atari 2600/7800 Composite MOD

Post by rubber_jonnie » Mon Mar 19, 2018 9:50 am

atari030 wrote:
Mon Mar 19, 2018 9:13 am
Good stuff. I have a Jr I spannered playing with video mods a while back. Glad you did this as I needed some motivation to get on to it. I have a vader I put sockets on, wish I had used cables as I hat things that aren't reversible.
Cool, glad it's inspired you :)

Here's the cable with the can back on, I had to do some bending of the tin, but it's reversible.
I put a knot in the cable for strain relief, and used a small tie wrap through the old tv out holes.
JR.jpg
JR.jpg (463.41 KiB) Viewed 494 times
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

atari030
Posts: 52
Joined: Mon Feb 12, 2018 12:43 pm

Re: Atari 2600/7800 Composite MOD

Post by atari030 » Mon Mar 19, 2018 12:27 pm

Nice work. How hard was it to get the modulator out? They tend to be soldered to pretty big grounding plates.

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exxos
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Re: Atari 2600/7800 Composite MOD

Post by exxos » Mon Mar 19, 2018 12:37 pm

Nice :)

Do you get any "rolling" effects in the black background colour ? Also can you try pole position and take a clear screenshot ? I saw some vertical blue lines in the "sky" on mine..
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

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rubber_jonnie
Posts: 472
Joined: Thu Aug 17, 2017 7:40 pm
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Re: Atari 2600/7800 Composite MOD

Post by rubber_jonnie » Mon Mar 19, 2018 12:44 pm

exxos wrote:
Mon Mar 19, 2018 12:37 pm
Nice :)

Do you get any "rolling" effects in the black background colour ? Also can you try pole position and take a clear screenshot ? I saw some vertical blue lines in the "sky" on mine..
No rolling effects, but I do get a funny ladder effect down the left hand side, but it's off to the side and doesn't affect gameplay.

Except with games that have black borders, where it isn't present.

I will get some screenshots, however I don't have Pole Position to try.
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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