Atari 7800 / 2600

[SegaSnatcher]

OK, next question - have you set VBlank to Regenerate? (If not, try it.)

I think I found the issue, I didn't realize some roms needed mapper extensions at the end of file.

[skooter]

Now what this core really needs is an optional frame buffer toggle for the few games that have weird output. Most games can handle the low latency V_Sync=2 setting no problem, but a few games are very problematic and it would be nice if one could turn on a buffer on the fly specifically for those games.

Can you give examples?

Condor Attack
Deadly Duck
Front Line
Turmoil

This is just a small list that came to mind now, there are many others games that won't work with v_sync=2 because they keep changing the number of lines (refresh rate) on-the-fly. VBlank Regeneration won't help on these ones.

[rhester72]

I see your point there - Condor Attack looks like Atlantis used to before vblank generation. Bummer.

[telengard]

Is there a particular setting for this core that could make Crystal Castles work? The playfield has no gems. My guess is this is a bank switching thing?

[akeley]

I've heard the 7800 core might be better for 2600 games at the moment. You can try this pre release version.

[LamerDeluxe]

Is there a particular setting for this core that could make Crystal Castles work? The playfield has no gems. My guess is this is a bank switching thing?

Enable the superchip option in the core settings

[Ashfall]

Is there a particular setting for this core that could make Crystal Castles work? The playfield has no gems. My guess is this is a bank switching thing?

Change the file extension to .F6S

[telengard]

thanks everyone!

[thorr]

I've heard the 7800 core might be better for 2600 games at the moment. You can try this pre release version.

Woah, I have been greatly looking forward to this core with 2600 support! Unfortunately I am having two major issues with it:
- I can't get it to use the keyboard to press Reset and Select. I can map the keys, but they don't work.
- SNAC is still broken. I can run "Bugs" which doesn't require a Reset to start, just a paddle button press. The paddle button works, but the movement does not. I have SNAC Analog set to Yes. On my SNAC enabled 2600 core, everything works fine. Edit: Found this on the discord page and it states that Paddles are currently broken. That gives me hope that it will be fixed. Now if I could just get Reset to work, I could start playing some games!

[Kitrinx]

I've heard the 7800 core might be better for 2600 games at the moment. You can try this pre release version.

Woah, I have been greatly looking forward to this core with 2600 support! Unfortunately I am having two major issues with it:
- I can't get it to use the keyboard to press Reset and Select. I can map the keys, but they don't work.
- SNAC is still broken. I can run "Bugs" which doesn't require a Reset to start, just a paddle button press. The paddle button works, but the movement does not. I have SNAC Analog set to Yes. On my SNAC enabled 2600 core, everything works fine. Edit: Found this on the discord page and it states that Paddles are currently broken. That gives me hope that it will be fixed. Now if I could just get Reset to work, I could start playing some games!

Paddles will never work via SNAC. the GPIO pins are a digital interface, and paddle movement is analog. It's not electrically possible. You will have to use some form of ADC for that purpose, but in reality, a usb adapter is a much better choice.

[thorr]

Paddles will never work via SNAC. the GPIO pins are a digital interface, and paddle movement is analog. It's not electrically possible. You will have to use some form of ADC for that purpose, but in reality, a usb adapter is a much better choice.

There is already an official Atari 2600 SNAC adapter available that I am using right now with an unofficial 2600 core. They use the ADC jack in combination with the GPIO pins. There is also a switch or jumpers (I have a switch) to select between Paddles and Joysticks connected to the adapter. You can purchase the adapters right now:

https://misterfpga.co.uk/product/mister ... -adapters/
https://misterfpga.co.uk/product/snac-c ... s-pcb-set/
https://www.ebay.com/itm/164958713999

The ADC jack comes on the DIgital I/O board (which I have) and for the Analog, you can get this: https://misteraddons.com/products/audio ... ard-adc-in

Here is a link where you can get the core that supports it. Please don't let this be the only version we will ever get that supports paddles with SNAC:

https://drive.google.com/drive/folders/ ... 7Rj-eGpCBS

Also, please fix it so I can use the keyboard in parallel when SNAC is enabled for Reset and Select, etc. Thanks!

My favorite Atari 2600 game is Kaboom. This requires lightning reaction times and works perfect with SNAC. I am afraid using any kind of USB adapter (of which I have several) is bound to add at least a little lag.

Off-topic, but maybe useful information: An issue built-in to Atari paddles is the turning range for each game is limited and the range that works floats from game to game. I replaced the potentiometers in one set of my paddles and it gave me a wider turning radius and more precise control. It works for all the games I tried it with, so a big portion of the paddles never gets used by any game.

[Kitrinx]

There is already an official Atari 2600 SNAC adapter available that I am using right now with an unofficial 2600 core. They use the ADC jack in combination with the GPIO pins. There is also a switch or jumpers (I have a switch) to select between Paddles and Joysticks connected to the adapter. You can purchase the adapters right now:

As far as I know, the Atari 2600 core doesn't even have SNAC support currently. There was some random prototype-y SNAC adapters floating around for it, one of which used the ADC. In the 7800 core the ADC is used for tape input, as it was designed to do.

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.

[Kitrinx]

Additionally, and just as an "Ackshyually" moment regarding "lightning fast", a lightning strike lasts around 60 microseconds, while the mister spinner type adapters have a latency of around 650-700 microseconds (0.7ish milliseconds). While it's not technically as fast as lightning it's only about 10 times slower.

[thorr]

As far as I know, the Atari 2600 core doesn't even have SNAC support currently. There was some random prototype-y SNAC adapters floating around for it, one of which used the ADC. In the 7800 core the ADC is used for tape input, as it was designed to do.

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.

Thanks for adding start and select! I am looking forward to trying this out! I am at work at the moment.

Regarding SNAC, should I use the Genesis SNAC adapter? With the older released 7800 core, I had issues even with joysticks and it didn't work with the Star Raiders keypad. If I am barking up the wrong tree, please let me know. I am not sure how to get the Star Raiders keypad to work. I will try everything out and let you know if there are any issues.

For paddles, I prefer to use the real paddles. I have a 2600daptor D9 that will covert real controllers to USB joysticks, so they might work. I think one paddle goes up and down and the other goes left and right and each has a button all showing up as one analog joystick. I can always use my otherwise inferior unofficial 2600 core for paddle games if it works better. I am not familiar with Ricardo's product. Do you have a link? It might be of interest. Edit: found it at ultimatemister.com. It looks very nice but it is not a handheld Atari Paddle with a thumb button. Thanks again!

[thorr]

Additionally, and just as an "Ackshyually" moment regarding "lightning fast", a lightning strike lasts around 60 microseconds, while the mister spinner type adapters have a latency of around 650-700 microseconds (0.7ish milliseconds). While it's not technically as fast as lightning it's only about 10 times slower.

Have you tried Kaboom? (no pun intended)

[remowilliams]

For paddles, I prefer to use the real paddles. I have a 2600daptor D9 that will covert real controllers to USB joysticks, so they might work. I think one paddle goes up and down and the other goes left and right and each has a button all showing up as one analog joystick.

Same, and I also use a D9. It used to work quite well (though with fiddly setup) in the older core at one point.

It's something I'm looking forward to working once again on the new shiny 7800/2600 core.

[Lightwave]

D9 here as well, hoping 2600 paddles will work smoothly with the adaptor when support is added to the core (works perfectly in Stella, so at least we know it's possible)

[telengard]

I too own those 2600 'daptors but I have had no luck even getting a joystick to work in the 2600 core, let alone the paddles. I'm able to assign L/R/U/D and Fire (and I skip the remainder), save settings, and they do not register at all in games. The MiSTer menu however works w/ the joystick. I'm sure I'm doing something very stupid...

[thorr]

I have added start and select for you as F1 and F2.

Kitrinx, I am home and finally got a chance to try this. First of all, congratulations on an AMAZING job well done. This is officially the best way ever to play Atari games, with a few exceptions. I put it through all of my standard stress tests and most things work perfectly. Great job! Here are the things I am having issues with and suggested improvements:

- Can you please swap F1 and F2? On a real Atari, the Reset is on the right. It feels really weird pressing those keys backwards (muscle memory).
- The Atari 2600 sound is perfect as far as I can tell. On Pitfall II, the music is nearly perfect. The pitch is great. The only issue is there seems to be a bit of static that I don't remember hearing before, especially in the right speaker.
- SNAC works fine with the Atari 2600 joystick. The buttons do not work on an Atari 7800 joystick. I can use the 2600daptor D9, but SNAC would be nice too if possible.
- I tried the Star Raiders keypad with SNAC and also the 2600daptor D9. I can't get it to work. I think there needs to be a way to program the buttons for the keypad in the core, or get it to work with SNAC. Star Raiders is another of my favorite games of course.

That is all I can think of at the moment (besides getting great Paddles support in one form or another). Thanks again!

[thorr]

I too own those 2600 'daptors but I have had no luck even getting a joystick to work in the 2600 core, let alone the paddles. I'm able to assign L/R/U/D and Fire (and I skip the remainder), save settings, and they do not register at all in games. The MiSTer menu however works w/ the joystick. I'm sure I'm doing something very stupid...

Try pressing F12 and look for things like Swap joysticks and also you might need to program the "buttons" directly in the core.

[Lightwave]

I too own those 2600 'daptors but I have had no luck even getting a joystick to work in the 2600 core, let alone the paddles. I'm able to assign L/R/U/D and Fire (and I skip the remainder), save settings, and they do not register at all in games. The MiSTer menu however works w/ the joystick. I'm sure I'm doing something very stupid...

Definitely works with Atari joysticks, are you starting games with reset (i.e. the console reset button mapped to another controller, not MiSTer reset)?
Only a few games will start with the fire button.

[Kitrinx]

I have added start and select for you as F1 and F2.

Kitrinx, I am home and finally got a chance to try this. First of all, congratulations on an AMAZING job well done. This is officially the best way ever to play Atari games, with a few exceptions. I put it through all of my standard stress tests and most things work perfectly. Great job! Here are the things I am having issues with and suggested improvements:

- Can you please swap F1 and F2? On a real Atari, the Reset is on the right. It feels really weird pressing those keys backwards (muscle memory).
- The Atari 2600 sound is perfect as far as I can tell. On Pitfall II, the music is nearly perfect. The pitch is great. The only issue is there seems to be a bit of static that I don't remember hearing before, especially in the right speaker.
- SNAC works fine with the Atari 2600 joystick. The buttons do not work on an Atari 7800 joystick. I can use the 2600daptor D9, but SNAC would be nice too if possible.
- I tried the Star Raiders keypad with SNAC and also the 2600daptor D9. I can't get it to work. I think there needs to be a way to program the buttons for the keypad in the core, or get it to work with SNAC. Star Raiders is another of my favorite games of course.

That is all I can think of at the moment (besides getting great Paddles support in one form or another). Thanks again!

After learning my lesson with the NES core, the keypad buttons just use the keyboard.
// 1,2,3 ---> 1,2,3
// 4,5,6 ---> Q,W,E
// 7,8,9 ---> A,S,D
// *,0,# ---> Z,X,C

that's the pattern, make sure to set the controller type to keypad. SNAC should also work with it (bidirectionally) so maybe some wires are crossed, but I don't have one of those controllers so I'm not really sure, and I can't debug it. If you decide to try Thrust make sure to use the omega boost grip as the controller type. By default, the controller type is two button (ie genesis) controllers. I haven't noticed any negative effects from using it vs a standard two button atari 7800 controller in 1 button mode.

I will swap F1 and F2 for you.

Hopefully paddles will be flexible and not require a PhD to configure when I get them implemented.

Regarding pitfall II, it's difficult to tell. A real system will have ~3khz filtering from the RF unit, and it seems pretty noisy in general, maybe some of the static is just high frequency noise? To further complicate it, it used a low quality oscillator that varied wildly in speed so it actually doesn't have a consistent music speed from cart to cart. Weird cart.

[redsteakraw]

Am I wrong could't a snac be done with a ADC hookup on the analog pins I would have made Mr.Spinner adapters as I made several Daemonbite adapters for various controllers. The Atari Joystick works with my Genesis Daemonbite adapter so no worries there. The main problem is that the Mr.Spinner adapter won't work with the atari paddles as they are you would have to modify the controllers for the device to work and I don't want to modify existing controllers. I have a Daptor D9 and for your average game it is a pain to setup. The other problem is that the System itself was an extension to the controller so unless you have a serious of switches set up or a non standard controller with extra buttons you are not giong to be able to open the OSD and or easily interact with the games as reset and select are key and some games made use of the black and white and dificulty switches in game. Space Shuttle comes to mind. What an ultimate atari adapter would be a mockup of the six switch panel and six db-9 ports two for joysticks two for paddles and 2 for keyboard controllers. So you can plug in what you need and just play.

The bigger problem is that the video on the current core is still off. I use Tapper as the benchmark, and while playable it has a very jittery look which isn't apparent on real hardware. So for now I am sticking to the games that are joystick and that display well like frogs and flies. Keystone kapers, Demon Attack and Spider Fighter. The core has come a long way since the beginning though and that is thanks to the hard work of the devs and contributors.

[thorr]

After learning my lesson with the NES core, the keypad buttons just use the keyboard.
// 1,2,3 ---> 1,2,3
// 4,5,6 ---> Q,W,E
// 7,8,9 ---> A,S,D
// *,0,# ---> Z,X,C

that's the pattern, make sure to set the controller type to keypad. SNAC should also work with it (bidirectionally) so maybe some wires are crossed, but I don't have one of those controllers so I'm not really sure, and I can't debug it.

Thanks! If there is anything I can do to help, please let me know. Maybe you can create a tester core and I can press the buttons and let you know what it says/does. Here is a picture of the inside: https://the-liberator.net/site-files/re ... er-003.JPG and here is a video going into great detail how to build the controller with schematics in the video: https://www.youtube.com/watch?v=FICpISoyDAA I tried playing with the keyboard as noted above, and it seems to be at least partially working. It's been a long time since I played the game and I am having trouble remembering how to navigate around on the Gal map. I can bring it up and close it, but there is more to it than that (Hyperspacing around). I may need to hook up my real Atari and/or read the instructions again. Getting older sucks.

If you decide to try Thrust make sure to use the omega boost grip as the controller type.

Never heard of that until now. I will have to check that out!

By default, the controller type is two button (ie genesis) controllers. I haven't noticed any negative effects from using it vs a standard two button atari 7800 controller in 1 button mode.

I am not quite sure I follow you. Are you saying in order for SNAC to work in two button mode, I need to use a Genesis controller instead of an Atari 7800 controller? I am testing with Commando, and no buttons work on the Atari 7800 controller. It would be great if the 7800 core could use 7800 controllers as the default.

I will swap F1 and F2 for you.

Awesome, thanks!

Hopefully paddles will be flexible and not require a PhD to configure when I get them implemented.

Agreed! I am sure you will be able to come up with some kind of acceptable solution. Just to beat a dead horse into a pile of goo, maybe you could implement them the SNAC/ADC way using a menu option to toggle the function of the ADC between tape and paddles. This would be ideal since there would be no funky calibration or other craziness. Same with the Driving controller. The developer who did the work on the Atari 2600 SNAC core that was never published to the main core is named blue1 (if you wanted to reach out to him). His test core worked with paddles and the driving controller, and joysticks, but not the Star Raiders keypad. I provided a link to the core a few posts ago if you want to try it. You have to turn off the ADC inside the core menu in order to use joysticks with SNAC and turn it on in order to use paddles.

Regarding pitfall II, it's difficult to tell. A real system will have ~3khz filtering from the RF unit, and it seems pretty noisy in general, maybe some of the static is just high frequency noise? To further complicate it, it used a low quality oscillator that varied wildly in speed so it actually doesn't have a consistent music speed from cart to cart. Weird cart.

Yes, I am aware of the cart to cart speeds. I am quite happy with the speed you picked! The static does sound like high frequency noise. Maybe you can implement a low pass filter for the Pitfall II chip.

Thanks again for everything!

[Kitrinx]

he bigger problem is that the video on the current core is still off. I use Tapper as the benchmark, and while playable it has a very jittery look which isn't apparent on real hardware. So for now I am sticking to the games that are joystick and that display well like frogs and flies. Keystone kapers, Demon Attack and Spider Fighter. The core has come a long way since the beginning though and that is thanks to the hard work of the devs and contributors.

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.

[Kitrinx]

Thanks! If there is anything I can do to help, please let me know. Maybe you can create a tester core and I can press the buttons and let you know what it says/does. Here is a picture of the inside: https://the-liberator.net/site-files/re ... er-003.JPG and here is a video going into great detail how to build the controller with schematics in the video: https://www.youtube.com/watch?v=FICpISoyDAA I tried playing with the keyboard as noted above, and it seems to be at least partially working. It's been a long time since I played the game and I am having trouble remembering how to navigate around on the Gal map. I can bring it up and close it, but there is more to it than that (Hyperspacing around). I may need to hook up my real Atari and/or read the instructions again. Getting older sucks.

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.

I am not quite sure I follow you. Are you saying in order for SNAC to work in two button mode, I need to use a Genesis controller instead of an Atari 7800 controller? I am testing with Commando, and no buttons work on the Atari 7800 controller. It would be great if the 7800 core could use 7800 controllers as the default.

The way 7800 controllers work is a bit awkward for SNAC. It was a bit of a hack on the original system to make it compatible with 2600. They pull up the fire button pin strongly, which ends up driving the two analog pins. I think probably being only an open drain system, there is not enough current for that pin to pull up to the extent that it needs to.

Agreed! I am sure you will be able to come up with some kind of acceptable solution. Just to beat a dead horse into a pile of goo, maybe you could implement them the SNAC/ADC way using a menu option to toggle the function of the ADC between tape and paddles. This would be ideal since there would be no funky calibration or other craziness. Same with the Driving controller. The developer who did the work on the Atari 2600 SNAC core that was never published to the main core is named blue1 (if you wanted to reach out to him). His test core worked with paddles and the driving controller, and joysticks, but not the Star Raiders keypad. I provided a link to the core a few posts ago if you want to try it. You have to turn off the ADC inside the core menu in order to use joysticks with SNAC and turn it on in order to use paddles.

I don't have any plans of using the ADC for paddles in additional to tape audio. Mr Spinner does have a design for atari 2600 paddles as far as I know, and it doesn't have be inside them, it can be an external adapter. This is the one from Ricardo I'm talking about https://ultimatemister.com/product/ultimate-spinner-pro It's kind of pricy but well made.

Yes, I am aware of the cart to cart speeds. I am quite happy with the speed you picked! The static does sound like high frequency noise. Maybe you can implement a low pass filter for the Pitfall II chip.

There's no need. MiSTer framework has a filter option for audio already, and a pack of filters. The arcade low pass filters are what you're looking for.

[redsteakraw]

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.

[telengard]

I too own those 2600 'daptors but I have had no luck even getting a joystick to work in the 2600 core, let alone the paddles. I'm able to assign L/R/U/D and Fire (and I skip the remainder), save settings, and they do not register at all in games. The MiSTer menu however works w/ the joystick. I'm sure I'm doing something very stupid...

Definitely works with Atari joysticks, are you starting games with reset (i.e. the console reset button mapped to another controller, not MiSTer reset)?
Only a few games will start with the fire button.

Yeah, I usually test with Adventures of Tron which starts a game just by moving the joystick. I will dig into this some more. Does the joystick have to be setup as a whole for MiSTer before setting up for the 2600 core? I was looking for a spot to do that (I thought I had done this for my 8bitdo pad) and couldn't find it.

[Lightwave]

I too own those 2600 'daptors but I have had no luck even getting a joystick to work in the 2600 core, let alone the paddles. I'm able to assign L/R/U/D and Fire (and I skip the remainder), save settings, and they do not register at all in games. The MiSTer menu however works w/ the joystick. I'm sure I'm doing something very stupid...

Definitely works with Atari joysticks, are you starting games with reset (i.e. the console reset button mapped to another controller, not MiSTer reset)?
Only a few games will start with the fire button.

Yeah, I usually test with Adventures of Tron which starts a game just by moving the joystick. I will dig into this some more. Does the joystick have to be setup as a whole for MiSTer before setting up for the 2600 core? I was looking for a spot to do that (I thought I had done this for my 8biddo pad) and couldn't find it.

Yes, when MiSTer boots up, you'll be in the "Menu" core, you need to map the Joystick here first.

[Chris23235]

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.