Returning ex-7800 owner with my "new" 7800.

[Gunstar]

Hello 7800 fans and owners. So, I used to come to this forum and participate probably pre-2005 or so, though I have maybe commented in the forum once or twice over the last decade and a half. Many of you will know me as a regular in the Atari 8-bit forums for 20 years, or maybe the Jaguar forums I used to participate in up to about 5 years ago. I still own a Jaguar (w/CD unit) and love it. but I've had so much going on in the A8 world the last 5 years, since I fixed my Atari computers after about a 4-5 year hiatus, I just don't participate in the Jag community for that and other reasons.

 

So, I owned a 7800 since about '86/87, from about Atari Corp.'s release of it until around 2005/6 when I sold off a lot of my vintage collection. I've slowly been rebuilding a more modest vintage console/computer collection again, and it finally came time for me to listen to the call of the 7800. Especially since it was a PAL 7800 that I could play those PAL titles never released in the states and repro's of the lost Tynsoft shooters (NOT an emulator guy, though I have used them occasionally on my Dreamcast, including 7800 emulator), and of course there are a few 7800 home-brews that interest me. I posted pics and news my ownership in my profile news feed last week.

 

I guess I'll have to get one of these new-fangled SD/flash cartridges for my 7800 sooner or later. I only have Desert Falcon, Pole Position II and of course the built-in Asteroids Deluxe in the PAL 7800. I of course have a Vader 2600 and a half-dozen games with it on display under glass including some of my classic faves from Imagic: Star Voyager, Cosmic Ark, Atlantis and Moonsweeper...and the best 2600 game ever...Solaris.

 

My old favorites for the 7800 included Commando, Into The Eagles Nest, Ikari Warriors, Xenophobe, Motor Pyscho, Fatal Run and Ball Blazer. Of course half of these and most of the rest of the 7800 library titles are on the Atari 800/XL/XE which I had prior to the 7800, especially the arcade classics and though some of them were better versions on the 7800, not better enough to justify my purchasing them again for the 7800, IMO. So the 7800 was always my "back up" system for a few games that never made it to the Atari 800 (well, some recently as both lost titles and home-brews), so most of the games I owned were ones I couldn't get on my 8-bit computer at the time. 

 

I did have the Euro pad controllers for my NTSC 7800 before I sold it, and an S-video/audio mod. This PAL unit came with a audio/video out mod, but it looks worse than RF, so whomever did it botched the job. I'll have to go back in... this unit came with one pad and one pro-line controller.

 

I do very much prefer the large rainbow stripe and large Atari and Fuji on the metal trim over the NTSC version with the thin stripe and small Atari, Fuji and 'Prosystem' lettering. Almost as much as I like the Sears Video Arcade II or Japanese 2800 console versions of this prolific case.

 

Another bonus for me returning to the 7800 these days is I happen to have half a dozen Pokey chips now, as over the past year I've been converting my Atari 8-bit computers from dual-Pokey upgrades to Pokeymax boards, so I've got plenty to put into 7800 titles that need them! The irony being that just over a decade ago I was stripping Pokey chips from Ball Blazer carts I bought off ebay for >$5 to make those dual-Pokey stereo upgrades!

 

 

 

Edited July 22, 2021 by Gunstar

[+x=usr(1536)]

4 hours ago, Gunstar said:

I guess I'll have to get one of these new-fangled SD/flash cartridges for my 7800 sooner or later.

Yes. Yes, you will. Welcome back ?

[desiv]

There are no "ex-7800" owners...

Only "will soon again be 7800" owners...

 

Welcome back...

 

And there are even more great homebrews and SD carts available now!

[juansolo]

On 7/22/2021 at 9:30 PM, Gunstar said:

This PAL unit came with a audio/video out mod, but it looks worse than RF, so whomever did it botched the job. I'll have to go back in...

There's a LOOOONG thread that goes down the PAL video rabbit hole here:

The PAL machine is severely compromised in a three major ways. Two of which we've addressed there and the third I'm fairly certain is inherent to the PAL MARIA. Long story short: The shared clock between the TIA and MARIA causes interference, disconnecting the MARIA and running it from it's own colourburst clock negates this. Secondly the chroma signals are blended before output and have an effect on each other meaning you can get one good at the expense of the other. Switching the chroma dependent on what cart is in it gets around that (though you'll then have to re-set the colour trimmers as they'll be wrong, which they always are on a PAL machine anyway...). The last is a colour rolling distortion that seems to vary from machine to machine in terms of intensity, but they all seem to do it. This seems to be coming from the MARIA and is heat dependent. Nothing really we can find what to do with that.

 

If you want to skip all the fluff, the schematic is at the top of page 9 and there's an all in one vero layout at the bottom of page 8. There's an out of date document kicking around on page 6 in the middle (look for version 2.2) that has pics of the installation and what to pull. I still haven't updated it for the latest revision though because we're eventually (we keep getting distracted) planning to do a PCB for it. Ignore the NTSC stuff in that doc it's been superceeded (different thread!).

 

The UAV alone on the PAL machine doesn't really look good, but the UAV + the chroma switch and seperate clock gives about the best pic we've had out of a PAL machine. It's still not a patch on the NTSC machine with just the UAV. The PAL machine is very seriously flawed in comparison so a bad pic out of one is kinda the norm sadly unless you've got a much more extensive mod to try and get around those flaws.

 

Edited July 25, 2021 by juansolo

[juansolo]

I was up early and bored... V3 of the doc done. I've simplified it a lot and it's got it all in one place again.

 

AntiJackModDocV3.pdf

Edited July 25, 2021 by juansolo
Couple of mistakes in doc, updated now.

[Gunstar]

9 hours ago, desiv said:

There are no "ex-7800" owners...

Only "will soon again be 7800" owners...

 

Welcome back...

 

And there are even more great homebrews and SD carts available now!

Thanks, and there would have to be more since I owned one, since there were zero back then as far as I recall.

[Gunstar]

5 hours ago, juansolo said:

There's a LOOOONG thread that goes down the PAL video rabbit hole here:

The PAL machine is severely compromised in a three major ways. Two of which we've addressed there and the third I'm fairly certain is inherent to the PAL MARIA. Long story short: The shared clock between the TIA and MARIA causes interference, disconnecting the MARIA and running it from it's own colourburst clock negates this. Secondly the chroma signals are blended before output and have an effect on each other meaning you can get one good at the expense of the other. Switching the chroma dependent on what cart is in it gets around that (though you'll then have to re-set the colour trimmers as they'll be wrong, which they always are on a PAL machine anyway...). The last is a colour rolling distortion that seems to vary from machine to machine in terms of intensity, but they all seem to do it. This seems to be coming from the MARIA and is heat dependent. Nothing really we can find what to do with that.

 

If you want to skip all the fluff, the schematic is at the top of page 9 and there's an all in one vero layout at the bottom of page 8. There's an out of date document kicking around on page 6 in the middle (look for version 2.2) that has pics of the installation and what to pull. I still haven't updated it for the latest revision though because we're eventually (we keep getting distracted) planning to do a PCB for it. Ignore the NTSC stuff in that doc it's been superceeded (different thread!).

 

The UAV alone on the PAL machine doesn't really look good, but the UAV + the chroma switch and seperate clock gives about the best pic we've had out of a PAL machine. It's still not a patch on the NTSC machine with just the UAV. The PAL machine is very seriously flawed in comparison so a bad pic out of one is kinda the norm sadly unless you've got a much more extensive mod to try and get around those flaws.

 

Thank you for the info and link to the thread. When I use my video-to-VGA converter/scaler the PAL 7800 image (7800 mode) actually looks ok as the converter is an incredible piece of kit. But if I plug it straight in via video, or use my (very cheap Chinese) video-to-HDMI converter the image is just horrid, but if I do a better video mod, or RGB mod (I have an equally impressive RGB-to-VGA converter/scaler by the same company) and use my VGA converters I should have a pretty damn good picture by then.

[+-^CrossBow^-]

1 hour ago, Gunstar said:

Thank you for the info and link to the thread. When I use my video-to-VGA converter/scaler the PAL 7800 image (7800 mode) actually looks ok as the converter is an incredible piece of kit. But if I plug it straight in via video, or use my (very cheap Chinese) video-to-HDMI converter the image is just horrid, but if I do a better video mod, or RGB mod (I have an equally impressive RGB-to-VGA converter/scaler by the same company) and use my VGA converters I should have a pretty damn good picture by then.

If you can come up with a good RGB upgrade that handles both of the different color bursts equally, then you will be quite busy getting those kits made up as the demand for RGB from a 7800 is near frothing at this point.

 

[juansolo]

37 minutes ago, -^CrossBow^- said:

If you can come up with a good RGB upgrade that handles both of the different color bursts equally, then you will be quite busy getting those kits made up as the demand for RGB from a 7800 is near frothing at this point.

For PAL systems, definitely. For NTSC, I don't see the demand being as high given the quality of the picture with a UAV. It's just way easier and cheaper to drop one of those in and get good results. I still think the variance in the machines and the nature of the two sources make the RGB mod for the 7800 overly complex (expensive...). Sacrificing 2600 back compatibility would certainly help, I'm just not sure how many people would be prepared to do that.

[+-^CrossBow^-]

12 minutes ago, juansolo said:

For PAL systems, definitely. For NTSC, I don't see the demand being as high given the quality of the picture with a UAV. It's just way easier and cheaper to drop one of those in and get good results. I still think the variance in the machines and the nature of the two sources make the RGB mod for the 7800 overly complex (expensive...). Sacrificing 2600 back compatibility would certainly help, I'm just not sure how many people would be prepared to do that.

And that is part of the reason why I don't think we have seen something as yet for RGB on the 7800. Getting something made that works for both modes equally is the challenge I'm sure.

 

[Gunstar]

I can live without 2600 mode on my PAL 7800 as I have a perfectly good NTSC Vader 2600 too, so it gives me an excuse to pull her out still once in a while. Though 2600 gaming is a rare thing for me anyway. There are only a handful of titles I go back to on the 2600, always having better versions of most of my old 2600 favorites on my Atari 8-bit computer or when I owned the 7800 last for some of the classics like Pac-man and Donkey Kong, Dig Dug, etc. So playing the 2600 is just for a few of my old favorites like Solaris, and I prefer the 2600 versions of most Imagic games and a few Activision games. I didn't get a 7800 to play 2600 games and the backwards compatibility has never been of much use to me since I've always had a 2600 around.

 

By the way, without even thinking about it at first, I've been playing my NTSC 2600 Imagic games Atlantis, Cosmic Ark and Star Voyager on my PAL 7800 without issue, except the colors are off. Will all NTSC 2600 games work fine on a PAL 7800? Do NTSC 7800 games work on a PAL 7800?

Edited July 25, 2021 by Gunstar

[+-^CrossBow^-]

31 minutes ago, Gunstar said:

By the way, without even thinking about it at first, I've been playing my NTSC 2600 Imagic games Atlantis, Cosmic Ark and Star Voyager on my PAL 7800 without issue, except the colors are off. Will all NTSC 2600 games work fine on a PAL 7800? Do NTSC 7800 games work on a PAL 7800?

No...  not all of them will and I think that with a modified bios that more PAL games play on the NTSC vs the other way around. But just have to plug them in and see what happens.

 

 

[juansolo]

The PAL 7800 doesn't have the region lockout that the NTSC one has, but compatibility is patchy. As you've seen some things work but the palette is wrong, some things work and have on-screen corruption (usually not too bad), some things will run but they'll be a bit slow, and finally some things just don't work at all.

 

You might be lucky and have a PAL 7800 that can handle 2600 homebrew ok (usually the custom board stuff), but in our experience they're rare (mine runs most things, most others we've tried don't). There's an incomming solution to that one though in the form of a new BIOS.

[Gunstar]

As I said, the composite video, direct connect or through a video-to-HDMI converter looks as bad as RF, with interference. Here is what my video-to-VGA converter/scaler can do with the signal. Not too bad I guess. This of course is after the signal has been line-doubled/upscaled to 480p/576p, motion-adaptive de-interlacing and 3D comb filtering and output at SXGA 1280x1024 at 60Hz. With every other video or S-video device I use with this converter the images are crystal clear and my Atari 8-bit's (with DIY video upgrades) look every bit as good as Altirra emulator output via VGA. I can also choose to turn on or off the 3D comb filtering and have perfectly sharp edged pixels, or on and smooth everything out. With the PAL 7800 video, it won't allow me to turn off the filtering.

 

 

Edited July 25, 2021 by Gunstar

[Gunstar]

Just for kicks I went into my storage shed and pulled out as many more 2600 carts as I could find in a few minutes, to test if they'd work on my PAL 7800.

 

I already knew that the Imagic games Atlantis, Cosmic Ark and Star Voyager worked. out of 8 cartridges, 6 work perfectly fine: Tele-Games Bowling, Space Invaders, Combat, Parker Brother's King Kong, Missile Command. Unfortunately Pac-man also worked fine. Demons to Diamonds had a crazy "flipping" display of the graphic screen and Jaw Breaker isn't even recognized by the 7800 and it boots straight to Asteroids! I know the game works on my 2600.

 

 

 

Edited July 25, 2021 by Gunstar

[+-^CrossBow^-]

Jaw breaker being a Tigervision game, it is possible that the pegs on the side are hitting the bottom of the 7800 PCB before the actual contacts in the PCB make..well contact with the cartridge slot itself. Unless your Jawbreaker has the spring loaded pegs on the sides of it?

 

[Gunstar]

2 hours ago, -^CrossBow^- said:

Jaw breaker being a Tigervision game, it is possible that the pegs on the side are hitting the bottom of the 7800 PCB before the actual contacts in the PCB make..well contact with the cartridge slot itself. Unless your Jawbreaker has the spring loaded pegs on the sides of it?

 

Not spring loaded. My Parker Brothers Sky Skipper is like that though(I called it King Kong before, the label is missing and that's what the game reminded me of.). But I see what you mean about pegs being so long on the Tigervision cartridge. a simple enough fix. I did look before, but it was to see if the PCB had pushed in or was dirty/corroded. I wouldn't have guessed that anyway, thanks!

Edited July 26, 2021 by Gunstar

[juansolo]

8 hours ago, Gunstar said:

I've seen worse...

 

Try the AJM to it and see if it improves things. Though it doesn't work miracles, it should be better than that.

[+-^CrossBow^-]

8 hours ago, Gunstar said:

Not spring loaded. My Parker Brothers Sky Skipper is like that though(I called it King Kong before, the label is missing and that's what the game reminded me of.). But I see what you mean about pegs being so long on the Tigervision cartridge. a simple enough fix. I did look before, but it was to see if the PCB had pushed in or was dirty/corroded. I wouldn't have guessed that anyway, thanks!

There are 3 ways to get around this issue:

 

1. is that you could clip the pegs on the cart in shorter allowing the cart to seat in fully and make proper contact. But this can be seen as a destructive fix to the game.

2. is that you could modify the cartridge sleeve which is where the issue lies. That is what I did on mine. You have to cut out the portion of the cart sleeve where the screws go into the sleeve from the bottom of the PCB. Is the mount sections in the plastic of the sleeve for those screws that prevents the Tigervision carts from seating all the way in. As long as the plastic snap tabs on the cart sleeve are in good shape, you don't really need the screws to hold the cart sleeve in place since it isn't likely to fall 'up' with the top cover over it anyway.

3. is to look at getting one of the 2600 Lock-On adapters. It is made by Winzmod or at least sold through them. It is what it sounds like. A 3d printed extension that plugs into the 7800 and then you plug the game ontop of it. It serves the dual function of both allowing tigervision carts to seat in all the way as well as other 3rd party carts that might fit tightly due to the lack of tolerance in the 7800 cart sleeves for different sized carts.

 

[Gunstar]

I appreciate the solutions @-^CrossBow^- , but as I have a 2600 (that I'm going to be doing some minor mods and upgrades too), my 7800 will almost never have a 2600 game inserted in it except if I choose to play one while the 2600 is being worked on, and Jaw Breaker is the only Tigervision game I have and  I don't even like it or play it, even on the 2600. So I feel no need to do a modification even though I commented that it would be an "easy fix."

 

I doubt I'll ever own another Tigervision cartridge, because as I said in an earlier post, I rarely play the 2600 and there are only a half-dozen games I still like on it that either aren't on other systems or I just prefer the 2600 version. Otherwise I'd rather play the classics on my Atari 8-bit or the 7800 versions of the few it has.

 

The 7800 will be only used for 7800 games, and with a Dragonfly in my hands, hopefully soon, that's pretty much going to be the only thing ever in my 7800 cart port except maybe a few home-brew 7800 games from the AA store, if rom images aren't available and I'm interested (very few new 7800 games at AA store that interest me).

[Gunstar]

Well, I've decided to do my own Anti-jack mod to my PAL 7800. I'm sure that the S-video signal I get through it, in combination with my video2VGA converter/scaler will be acceptable to me. I mentioned interest in an RGB mod, after some of you mentioned it, but that's because I misunderstood and thought there was already a working schematic of one for me to build. I'm not interested enough to invent my own.

 

So, I decided to open up the 7800 this evening to see what had already been done to it with the mono audio and composite video mod already installed in it. It's just a simple mod pulling the signals from the mobo, aside from a switching transistor on the video line, requiring a small board and two resisters to power it. The audio just passes through and I'm not sure why they even bothered instead of an audio wire and ground wire straight to the audio jack. It's just extra soldering work and extra work making the board  including audio in/out connections on it.

 

Whom ever did the mod couldn't drill a couple of holes straight for the RCA jack! It looks very amateurish and not something you'd ever see in one of my modifications. I make mine look like they were done at the factory (I'm referring to case modifications only, inside upgrades always looks good, but not always like they were factory made). I'm glad they are hidden underneath at least. and since I don't want to remove them and just have holes or attempt a case patch, I'll just use them for dual-mono and stereo audio out if I decide to install a Pokeymax in the Dragonfly, eventually, when I get one. To start with I'll just have a standard Pokey in there from one of my computers that already have Pokeymax's.

 

They left the RF case hole and channel switch hole empty, so I'll be using the old RF hole to mount my S-video jack and I'll re-install a switch where the channel selector switch used to be to select between dual-mono and stereo.

 

Has anyone seen this board before? Was this a homebrew hardware mod that was sold at one time or is this just someone's proto? Just curiosity, It's getting ripped out and tossed tonight. I'd have done an S-video mod from the start anyway, and since this video mod is crap. There was glue on the pots when I opened it, though I removed it in preparation for my AJM, but it might not have been factory original glue, it was hot glue I think.

 

 

Edited July 27, 2021 by Gunstar

[juansolo]

Just looks like a simple composite mod. With the results I'd expect from one on a PAL 7800. It'll essentially be marginally better than RF.

[+-^CrossBow^-]

9 hours ago, Gunstar said:

 

Looks like the 2600/7800 simple composite kit from the guy out of Turkey as that is his work and layout for the board he sells.

 

You mentioned dual mono and stereo for the RCAs from the dragonfly? Yes, the PokeyMax can simulate two pokeys and yes there are two separate outputs you can wire from internally on the DF cart for this. But there is only the one external audio line to the 7800. So if you wanted to use built in RCAs for stereo, you would either have to add them to the DF cart itself somehow and pull just pokey from there, or you would have to install like a 3.5mm jack off the DF and also on the 7800 to act as passthrough and run it that way?

 

But yes, I've seen that composite board before...

https://www.ebay.com/itm/182209099928?hash=item2a6c823898:g:82IAAOxySE9Q6XzC

 

He used to have a website where he sold these outside of ebay, but I can't find it now and he doesn't seem to link that in his ebay listings so he might not have that anymore. I used to buy his Intellivision composite kits because overall they produced the best overall picture. But when he increased the prices on them I couldn't justify them over similar kits I could get more easily and not have to wait a long time to receive from shipping.

 

[Gunstar]

7 hours ago, -^CrossBow^- said:

Looks like the 2600/7800 simple composite kit from the guy out of Turkey as that is his work and layout for the board he sells.

 

You mentioned dual mono and stereo for the RCAs from the dragonfly? Yes, the PokeyMax can simulate two pokeys and yes there are two separate outputs you can wire from internally on the DF cart for this. But there is only the one external audio line to the 7800. So if you wanted to use built in RCAs for stereo, you would either have to add them to the DF cart itself somehow and pull just pokey from there, or you would have to install like a 3.5mm jack off the DF and also on the 7800 to act as passthrough and run it that way?

 

But yes, I've seen that composite board before...

https://www.ebay.com/itm/182209099928?hash=item2a6c823898:g:82IAAOxySE9Q6XzC

 

He used to have a website where he sold these outside of ebay, but I can't find it now and he doesn't seem to link that in his ebay listings so he might not have that anymore. I used to buy his Intellivision composite kits because overall they produced the best overall picture. But when he increased the prices on them I couldn't justify them over similar kits I could get more easily and not have to wait a long time to receive from shipping.

 

I was wondering how the stereo worked out of the dragonfly, since there is only the one cart audio line, but since I knew the DF could use Pokeymax I was just going to read the PDF manual and see how it works it. I'll just have the stereo off the DF and as a 3.5mm jack, but not as a pass-through, just as the output to an amplifier or amplified PC speakers. This is how I did the dual-Pokey stereo out on my 1200XL and how I did the Pokeymax Quad + Covox (soon to be Pokeymax V3) on my 800. If I want it to go to RCA inputs on speakers or amplifier I have 3.5mm-to-RCA Y-adapters and vice versa. I still use the mono audio out on the 800 and 1200XL's monitor ports as output center channel and or sub-woofer usually. I'll just use the two RCA jacks on the 7800 for a simple dual-mono and ad in a line-level audio pre-amp. The RF hole is where I'll mount the S-video jack,

 

I've was studying the Anti-Jack Mod, UAV, UAV+AJM another S-video only circuit from an Aussie from a few years back, and several others. I've decided to make my own from scratch, using some of a couple different S-video mod circuits and doing some experimenting of my own. I have an idea or two up my sleeve. I think the AJM is overly complicated and a convoluted solution (more so with UAV added in) and I think I have a more elegant and simple design in mind and no need for a cmos clock or crystal oscillator exclusively for Maria. And I've seen the UAV up against my DIY Supervideo 2.1 mod I did on my 1200XL, with a few tweaks of my own, and I think my DIY video looks better. I think I can do better on my own here...

 

I'm going to also experiment with a chroma-boost circuit I have in mind for richer and more vibrant color without over saturating or bleed, and an alternative to a separate clock for Maria. Maybe I'm wrong about what I think I can do, but I've done dozens of audio/video modifications on all sorts of consoles and computers over the years and think I can extrapolate from that experience to come up with a good video board of my own for the PAL 7800.

Edited July 27, 2021 by Gunstar

[juansolo]

3 minutes ago, Gunstar said:

I was wondering how the stereo worked out of the dragonfly, since there is only the one cart audio line, but since I knew the DF could use Pokeymax I was just going to read the PDF manual and see how it works it.

The Dragonfly isn't stereo. There's only a single audio line that comes from the cart slot. The dual Pokey support just gives you 8 channel sound or, IIRC, less channels at higher quality. Not 100% on that though. The Covox support comes with the Pokeymax also. If you just fit a standard Pokey, you just get standard Pokey support. Currently the dual pokey and covox isn't supported by much other than demos. The YM is used by the Pac-Man 40th Anniversary collection and quite a few titles use the single pokey.

 

The PAL 7800 has a single audio feed from the TIA also, that and the cart audio are mixed together to a single mono output. The NTSC 7800 has two audio channels from the TIA and the single cart audio. It's not technically stereo though. You can wire it as stereo but it won't be right and to make it pseudo stereo would require some active mixing to make it not sound odd. They're again, just all blended together as a single mono out.