Atari 7800 / 2600

[Kitrinx]

Off isn't the right word. The video is perfectly accurate, especially if you turn off the stabilization feature. The problem is the console wasn't well designed, and the game code had to worry about the vertical video timings, so they do chaotic things. The stabilizer does it's best to understand the intent of the games and make them work on a modern display, but there's limits. For me, tapper is perfectly stable, so I'm really not sure what you're talking about there.

That game uses 480i timings as a curiosity for the system. Maybe the coders didn't know how to 240p worked. I could enable interlaced video, but you won't like the results.

First off I want to thank you for your hard work. It truly is appreciated. To clarify, by off I am referring to using a IO board through component output. Specifically via analog output the video is bobbing up and down by a scanline and gives it a jittery effect. I agree the stabilizer used is very good now. Pretty much every game I throw at it works over the HDMI output and analog. I just checked my original console, MiSTer via IO analog and HDMI, HDMI spazed out and was jittery unless vblank is set to original and it looks clear and crisp and plays very well. Now over analog when vblank is set to original the OSD is jittering up and down and when set to regenerate it becomes crystal clear and stable. However the game in the background stays jittery regardless, the only difference is that the regenerate adds black crop bars on the top and bottom. The comb artifacts look like thicker grey bars as they are jiggling up and down. But yes over HDMI it works well on original VBlank this seems to be an analog problem only. My 6 switch original system and cart and on that same analog TV has a stable yet predictably softer image with no jitter.

It may be your television just not liking the odd signal from tapper, it's very close if not identical to 480i, where each field alternates between a full scanline and a half scanline when the vsync begins. Does real hardware do this with that game on that television?

[Kitrinx]

I have added start and select for you as F1 and F2, as I don't think those keys will interfere with the POKEY keyboard input. Before release, I will be fixing the proper paddle input for mouse, analog sticks, and actually-official "mr spinner" compatible adapters. Ricardo makes a very nice spinner if you're interested in a quality paddle. Otherwise, SNAC should work for non-analog input as usual.

What a great core, many thanks Kitrinx. First I thought the B/W switch wasn't doing anything as I tried to switch the starfield on and off in Cosmic Arc but this seems to only be a feature of the PAL version, didn't knew this.

The core seems to be extremely accurate behaving like a real 7800 when I tried the PAL version of Robot Tank the picture didn't sync as it is on my real 7800, the NTSC version works fine also as on - at least some - of the NTSC 7800 consoles.

There are a few revisions of Cosmic Ark and the later ones have the optional starfield. Google for "Romhunter 2600". That pack has a very extensive collection of official roms, with all the different releases and revisions, and also a curated arrangement. It tends to have more working/correct roms than other packs, the exception being that it has the bad dump of Pink Panther.

Speaking of, other than starpath supercharger, there's a few other new bankswitching too:
-WD For Pink Panther (proper 8kb one only)
-MC for Circus Convoy
-3E for boulder dash and bad apple demo
and maybe some stuff I forgot

[redsteakraw]

It may be your television just not liking the odd signal from tapper, it's very close if not identical to 480i, where each field alternates between a full scanline and a half scanline when the vsync begins. Does real hardware do this with that game on that television?

No real hardware on that same tv looks fine just with a softer image because it is a RF connection. Something is slightly off with the analog output on the MiiSTer that the real hardware isn't doing. I don't Know why the OSD would be jittery but then just fine when you change the V-Sync but the overall game visuals remain jittery.

[Kitrinx]

It may be your television just not liking the odd signal from tapper, it's very close if not identical to 480i, where each field alternates between a full scanline and a half scanline when the vsync begins. Does real hardware do this with that game on that television?

No real hardware on that same tv looks fine just with a softer image because it is a RF connection. Something is slightly off with the analog output on the MiiSTer that the real hardware isn't doing. I don't Know why the OSD would be jittery but then just fine when you change the V-Sync but the overall game visuals remain jittery.

Possibly the RF encoding smooths over some problem then. In this case the vsync, vblank, are not ambiguous. There's a register and when it's set, they are on within a couple of pixel clocks. The hsync and hblank are very predictable and the whole system will break if they are off even the tiniest bit.

[redsteakraw]

Possibly the RF encoding smooths over some problem then. In this case the vsync, vblank, are not ambiguous. There's a register and when it's set, they are on within a couple of pixel clocks. The hsync and hblank are very predictable and the whole system will break if they are off even the tiniest bit.

I don't think it is the RF as the picture when jittering looks different and you can see the combing lines being grey instead of black. The comb lines are black and thin on the real hardware. I took my camera out and tried to record it and it looked fine but then I found the break in the rendering and it literally is shifting over. including the comb lines. It looks almost as if it was a Bob deinterlaced or similar to what is going on via HDMI when the vsync regeneration istn't set to original.

[thorr]

There is a tester rom for 7800 for the keypad and other controllers. Via the keyboard at least, the keypad appears to work fully. If there's a specific game not working with it, let me know what that is.

Hello Kitrinx,

I finally hooked up my real Atari 2600 and did extensive testing with Star Raiders and the keypad. Something is definitely broken with Star Raiders. How it is supposed to work on a real Atari 2600 is you should be able to plug the joystick into the left port, and the keypad in the right port. Pressing the upper left corner on the keypad (1) brings up Fore View so you can see where you are flying and shoot at stuff. Pressing (2) brings up the Gal Map. Once in the Gal Map, you should be able to move the cursor around the screen with the joystick. Pressing (3) Hyperwarps you to that square.

The problem with the 7800 core is in Star Raiders, when you configure the keypad as player 2 and the Joystick or SNAC for player 1, you can't move around with the joystick. The fire button works, but that is it. This makes it impossible to move around in Star Raiders either on the map or when flying the ship. I tried both SNAC and 2600-daptor D9's.

Regarding the actual real keypad, when connected to the 2600-daptor, it translates them to joystick buttons 1-12. If you could program the core to look for joystick buttons 1-12 on the second USB device, then the keypad should work. Currently, it does not work at all with SNAC or USB.

Also, without changing any configuration, I can load up another Atari 2600 game and the joystick movement works fine. It is just broken in Star Raiders.

Please let me know if you have further questions. Thanks for your help!

[Chris23235]

The 7800 core is now officially updated with the 2600 support. Many thanks Kitrinx.

It is an awesome recreation of the 7800. The automatic detection of the correct bankswitching types is also great. No more renaming roms or switching through the available mappers.

Just out of interest, how is the bankswitch detection done, has the core some kind of database for the different roms?

[caffeinekid]

Will this be backported to the stand alone 2600 emulator, assuming any of it is needed? I haven't really dived into these systems.

[KremlingKuthroat19]

Kitrinx mentioned that this is better than the Atari 2600 core since it has all the features + more. There isn't any need for the original 2600 core tbh and I think it'll be removed. If that's the case, then I get the notion that the Atari 2600 is super iconic and deserves its own seperate core, yet we aren't missing out on any features by using the 7800 core. It just makes it easier on the devs since only 1 core has to be maintained.

[caffeinekid]

I guess it make sense to have them bundled if this implementation is superior, but yes it would be nice to have it as a separate machine too just for completeness sake. I know it's not a big issue though if we can play all the games as they were intended.

[rhester72]

Is it still not possible to use keyboard for switches and joystick for input? (Ideally, I'd like to use a legitimate 7800 controller, but that'd be difficult for some 2600 games that used the switches as input.)

[FatSlob71]

Starpath supercharger

[Kitrinx]

It doesn't make a lot of sense to keep them separate IMHO. The only valid argument I can see in favor of it is "I like seeing the number 2600", while from a practical standpoint they use all the same accessories and controllers and three of the same chips. Dividing up the development of it just for the sake of vanity is a bit foolish.

[akeley]

It's not really "vanity" but a bit somewhat complex set of feelings which stem from the fact that some of use like to imagine these cores as real replacement for real hardware, in a particular way. It's a bit of a role play, admittedly, but is nonetheless a valid approach.

That's not to say that I expect any devs to devote their time to this, because it's great as it is already, but I hope that in the long run a separate core will eventually appear. And by "long run" I mean a 5-10-20 years timeframe, the period when most of the cores will be "complete" and there will be time to devote to such minor things (though I remain hopefull MSX will get proper treatment sooner than that, but it's a different story than 2600/7800 anyway).

[rhester72]

The challenge is dual maintenance and the inevitable disconnect that will occur - for example, sound improvements in one SHOULD carry over to the other, but likely won't with separate cores.

[akeley]

I did say "in the long run" for a reason...

[Chris23235]

It's not really "vanity" but a bit somewhat complex set of feelings which stem from the fact that some of use like to imagine these cores as real replacement for real hardware, in a particular way. It's a bit of a role play, admittedly, but is nonetheless a valid approach.

That's not to say that I expect any devs to devote their time to this, because it's great as it is already, but I hope that in the long run a separate core will eventually appear. And by "long run" I mean a 5-10-20 years timeframe, the period when most of the cores will be "complete" and there will be time to devote to such minor things (though I remain hopefull MSX will get proper treatment sooner than that, but it's a different story than 2600/7800 anyway).

I see your point, but the moment I put my 7800 under the TV was the moment I unplugged my 2600 and put it in the storage. The only reason to prefer the 2600 over the 7800 was that you prefered the case design of the 2600. But as the MiSTer can't replicate this I honestly don't see any point in a seperate 2600 core.

[rhester72]

I did say "in the long run" for a reason...

Unless the 'long run' means 'after MiSTer is abandoned as a platform', it will still apply...and afterwards it won't matter.

[akeley]

I see your point, but the moment I put my 7800 under the TV was the moment I unplugged my 2600 and put it in the storage. The only reason to prefer the 2600 over the 7800 was that you prefered the case design of the 2600. But as the MiSTer can't replicate this I honestly don't see any point in a seperate 2600 core.

Well, I do But there's really very little point arguing about it because the key point of my post was speculating on stuff that might happen in the future. 10 years ago there wasn't even MiST around, now we have this, and who knows what will it all look like in another 10, nevermind 20?

Unless the 'long run' means 'after MiSTer is abandoned as a platform', it will still apply...and afterwards it won't matter.

The "long run" means the future of retro computing/console on FPGA in general, not just one particular platform. Obviously, seeing as MiSTer didn't just appear out of the thin air.

[rhester72]

In 10-20 years, anyone still caring about 2600 gaming will be academic researchers and masochists. LOL Like many 'retro' platforms, its value lies largely (if not entirely) in nostalgia of those who enjoyed it when it was current/modern. I wish it were otherwise, but my kids' kids are not going to be playing 2600 games.

[dmckean]

In 10-20 years, anyone still caring about 2600 gaming will be academic researchers and masochists. LOL Like many 'retro' platforms, its value lies largely (if not entirely) in nostalgia of those who enjoyed it when it was current/modern. I wish it were otherwise, but my kids' kids are not going to be playing 2600 games.

I'm not old enough to have nostalgia for the 2600 but I really enjoy the system. Love the simplicity, most carts have no start screen and you're playing as soon as you power on. The mechanics to these old games are uncomplicated and you often find yourself having way more fun than you have any right to be.

[akeley]

In 10-20 years, anyone still caring about 2600 gaming will be academic researchers and masochists. LOL Like many 'retro' platforms, its value lies largely (if not entirely) in nostalgia of those who enjoyed it when it was current/modern. I wish it were otherwise, but my kids' kids are not going to be playing 2600 games.

That's quite a strange sentiment tbh, and I'm not quite sure it's entirely accurate either. I've never had a 2600, nor TRS-80, and a heap of other stuff, yet I enjoy using them immensely. And so do many other, even much younger than me, retro enthusiasts. You can extend this to watching Buster Keaton's films or reading Shakespeare. Not much to do with "nostalgia", really.

Anyway, no point splitting hair here. Let's revisit this "in the future", see how did it go

[MiSTer_Kirk]

The Megadrive plays Mastersystem games, so should we get rid of the Mastersystem core ?
Real SNES can play Gameboy games via the Super Game Boy Adapter, not sure about the core, but if it does then should we get rid of the Gameboy core ?
WonderSwan Color, can play Wonderswan mono games, hey lets get rid of that pesky Wonderswan core, right ?

Oh, but it's "Extra" work, cry 1 or 2. I mean, in the context of things, it's not like there are many, many other cores, right ?
Can you use a Starpath supercharger, on a 7800 ?
Out of the two, which is the more iconic console ? I would say the 2600 by a million miles - the 7800 was too late, utter junk, and flopped badly. I have a 7800 here, and the only connection I have with it was that it cost me £20, back in the late 80s, at a car boot sale. While my 2600 is a rare UK heavy sixer model, all boxed with all the paperwork, and is among my most treasured consoles ever.

[Chris23235]

Can you use a Starpath supercharger, on a 7800 ?

Yes

[skooter]

Other cores are divided into what makes sense from the development point of view.
For instance: we have Master System, Game Gear, and SG-1000 (three different systems) under the same core.
On the other hand, we have different cores for Mega Drive and Sega CD, and Sega CD doesn't exist as a standalone system.

[Kitrinx]

The Megadrive plays Mastersystem games, so should we get rid of the Mastersystem core ?
Real SNES can play Gameboy games via the Super Game Boy Adapter, not sure about the core, but if it does then should we get rid of the Gameboy core ?
WonderSwan Color, can play Wonderswan mono games, hey lets get rid of that pesky Wonderswan core, right ?

Oh, but it's "Extra" work, cry 1 or 2. I mean, in the context of things, it's not like there are many, many other cores, right ?
Can you use a Starpath supercharger, on a 7800 ?
Out of the two, which is the more iconic console ? I would say the 2600 by a million miles - the 7800 was too late, utter junk, and flopped badly. I have a 7800 here, and the only connection I have with it was that it cost me £20, back in the late 80s, at a car boot sale. While my 2600 is a rare UK heavy sixer model, all boxed with all the paperwork, and is among my most treasured consoles ever.

7800 is the best 2600! It's like the supergrafx of atari!

[Kitrinx]

In all seriousness, if the only thing bothering you is the term "7800" vs "2600", just add an entry to names.txt to change it to something that suits you better.

[MiSTer_Kirk]

The BEST 2600, is a 2600.

Is this a preservation device ?
Or a populist device ?

In all seriousness, if the only thing bothering you is the term "7800" vs "2600", just add an entry to names.txt to change it to something that suits you better.

I don't care about the 7800, it was full of crapware, and instantly forgettable games. The 2600 changed the whole landscape, and was a pioneer in the videogame industry. The 7800 was an embarrassment, and led to the start of the end for Atari.

[12characters]

Just out of interest, how is the bankswitch detection done, has the core some kind of database for the different roms?

I was also curious about this. Based on what I can make out of the source code, it appears to use elaborate guesswork with inspiration from software emulators.

Anyhow, +1 thank you to Kitrinx.

[Chris23235]

Is it still not possible to use keyboard for switches and joystick for input? (Ideally, I'd like to use a legitimate 7800 controller, but that'd be difficult for some 2600 games that used the switches as input.)

This would be great. Select and start are already mapped to F1 and F2. It would be great to have Left A/B, Right A/B and the Colour/BW switch mapped to F3, F4 and F5. The way it is done now makes it impossible to play e.g. Phaser Patrol with a 1 or 2 Button Joystick.