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rj1307

"Dragonfly" my version of the Atari 7800 SD cartridge

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Received my Dragonfly, and just gave it a quick test.

 

On my PAL 7800 (I'm in the UK), some games will crash after a short while, but not always at the same time. I use Pole Position II and Ninja Golf as tests. Also, sound balance between TIA and POKEY isn't great, with POKEY being louder than TIA. I have a composite mod board in this machine, and have a 47K resistor joining R32 and R33 - that addresses sound balance with actual carts. Turning the POKEY down doesn't alter this behaviour. I notice the comments from @-^CrossBow^- about mod boards, but rather than this just being a sound issue, the games crash completely.

On my NTSC 7800 which uses the same mod board, I have no crashing problems, and all sound balances are fine!

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Which version of the motherboard is causing these crashes? Do you have the option to take a picture of her?

To adjust the sound level of Pokey and Yamaha, there are three potentiometers available after removing the cartridge housing. This is described in the manual.
The fact that you have a difference in volume level between PAL and NTSC consoles doesn't depend on Dragonfly, it's just the resistors and mods in the consoles. 

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We've had a few PAL machines pass through our hands since we got our DragonFlys and have noticed that some of them have a little bit of an issue with ROMs from the DF, but not with original carts. Only two so far, but the symptoms are identical. @ultrasteve fire up the BallBlazer ROM, sometimes that one will crash after a few seconds.

 

This is something we had a poke at the other day when we saw @-^CrossBow^-'s video about having issues with early revision Pole Position II carts on the NTSC machine. Thought it'd nailed it when we added the cap he used to fix it on that and it worked flawlessly. However it was just one of those fluke times when it worked... Let it cool down again and the problem came back. It does odd things with homebrew sometimes also, if I put in my Pac-Man collection cart it flashes on-screen corruption for a bit before it warms up and it goes away...

 

There appears to be no distinguishing feature on the machines with the problems. But the problem definitely follows the machines and not the Dragonfly. It's very odd. If it wasn't for us leaving the EU and buggering up sending things to/from the mainland, I'd send it over for you to have a poke at it. As it is, if you have any suggestions I'm happy to poke around, take photos, and what have you.

Edited by juansolo

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It would be good to know where the "CA" cap from the Sobola NTSC schematic was added to the back of the actual board.  Then apply this to the PAL ones we have problems with.  Tried on the MARIA, but maybe it needs to be at the other end of the address bus, or a few smaller value caps, on the different chips A15 is connected to, and probably on the cart slot.

 

PAL 7800s are really crap.  But not as crap as a French SCART one, with super bodged "RGB"??  output.

 

Edited by marauder666

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1 hour ago, rj1307 said:

Which version of the motherboard is causing these crashes? Do you have the option to take a picture of her?

To adjust the sound level of Pokey and Yamaha, there are three potentiometers available after removing the cartridge housing. This is described in the manual.
The fact that you have a difference in volume level between PAL and NTSC consoles doesn't depend on Dragonfly, it's just the resistors and mods in the consoles. 

Of course, I understand about the resistors and the pots on the Dragonfly board - I was just observing that on my PAL 7800, if I DON'T have the 47k resistor, TIA/POKEY balance is no good. My NTSC one doesn't need a resistor added though, the sound is OK. With the 47K in my PAL, TIA/POKEY sound balance is good with the regular cart of Commando, but not with Dragonfly.

 

Board is C300633-001 REV C. Pictures attached. Ignore the temporary resistor work ;)

 

32 minutes ago, juansolo said:

We've had a few PAL machines pass through our hands since we got our DragonFlys and have noticed that some of them have a little bit of an issue with ROMs from the DF, but not with original carts. Only two so far, but the symptoms are identical. @ultrasteve fire up the BallBlazer ROM, sometimes that one will crash after a few seconds.

 

This is something we had a poke at the other day when we saw @-^CrossBow^-'s video about having issues with early revision Pole Position II carts on the NTSC machine. Thought it'd nailed it when we added the cap he used to fix it on that and it worked flawlessly. However it was just one of those fluke times when it worked... Let it cool down again and the problem came back. It does odd things with homebrew sometimes also, if I put in my Pac-Man collection cart it flashes on-screen corruption for a bit before it warms up and it goes away...

 

There appears to be no distinguishing feature on the machines with the problems. But the problem definitely follows the machines and not the Dragonfly. It's very odd. If it wasn't for us leaving the EU and buggering up sending things to/from the mainland, I'd send it over for you to have a poke at it. As it is, if you have any suggestions I'm happy to poke around, take photos, and what have you.

So for me, the Ballblazer ROM works fine on my DF (at least for about 10 minutes - didn't test longer! Pole Position II ROM on DF will fail every time, usually after less than a minute of playing. Graphic glitches start to appear, then the screen will either go mostly green, or some other garbled GFX, then crash completely.

With this exact 7800 I used to have problems with Ms Pac Man, exhibiting similar graphic issues as you mention with your homebrew Pac Man cart, and like you, they would go away once warmed up.

I also powered the 7800 and DF both from the same PSU, and each from different (good quality) ones to rule a power issue out.

 

And by the way, I'm NOT blaming Dragonfly, or saying there's a problem with it - I think there are enough of us now with various issues that suggest PAL 7800s are problematic, for some reason.

IMG_2730.jpeg

IMG_2731.jpeg

IMG_2732.jpeg

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Save revision board as all the PAL ones we've had.

Yours does have a EPROM OS, not same as mine or Juansolo's.  W5,W6 jumpers are different, but thats due to the EPROM needing an inverted CS signal.

Think Muddyfunster's was like yours.  Does it have a printed Atari logo on the top, or is it embossed?

 

Regarding audio, you should run the audio through 2 8.2k resistors from the right side on those pads on the board, connected together at one end to the wire going to the AV mod.  In fact 6.8k to 10k would be fine.  Ideally run the wire through a 1uf capacitor, unless thats on the mod.

 

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2 hours ago, marauder666 said:

It would be good to know where the "CA" cap from the Sobola NTSC schematic was added to the back of the actual board.  Then apply this to the PAL ones we have problems with.  Tried on the MARIA, but maybe it needs to be at the other end of the address bus, or a few smaller value caps, on the different chips A15 is connected to, and probably on the cart slot.

 

PAL 7800s are really crap.  But not as crap as a French SCART one, with super bodged "RGB"??  output.

 

I've found it factory added to a few 7800s, usually right off the 6502 itself and not further in the chain. I added mine at Maria on the one in my video I did. But yeah, last few I've noticed seem to use a ceramic banded cap, coming off the a15 line to ground right at the 6502 on NTSC systems.

 

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This is very interesting.

 

I always wondered why my Pole Position II cartridge would not work on my NTSC console! I thought it was just a bad cartridge.

 

I also have had a few games crash on my DF, so wonder if that capacitor needs adding on my motherboard?

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3 hours ago, Jouster said:

This is very interesting.

 

I always wondered why my Pole Position II cartridge would not work on my NTSC console! I thought it was just a bad cartridge.

 

I also have had a few games crash on my DF, so wonder if that capacitor needs adding on my motherboard?

In the video I did on this, PPII was never an issue other than slight graphical glitching on the 7800 rainbow BIOS screen and occasional flickers of pixels that shouldn't be on the track selection screen. Otherwise the game itself was always fine. BallBlazer was the only game to actually cause the 7800 to lockup with any degree of certainty. And it was just luck really that I happened upon what was up. Anyway, @Trebor owns that 7800 used in the video now and unless he has been too polite to tell me otherwise, it has been working fine since I added that small cap to it.

 

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I received my Dragonfly a short while ago safe and sound but didn't get a chance to try it until just now as I had to order an AC adapter (I thought for sure I'd have a compatible adapter somewhere, but turns out I didn't! lol).

 

Anyway, the adapter arrived today and I got everything up and running with no problems.  Great little device, and having to use the LCD/buttons on the cart is a lot less annoying than I thought it would be.  The 7800 library is so small, anyway, that it's no big deal to scroll through the list to get to the game you want.

 

I have encountered some issues here and there, but I'm sure they are due to either the ROMs I'm using or the system itself (Ballblazer definitely locks the system up a few seconds in).  Nothing else I tried had any issues.

 

Interestingly, I had modded my system (NTSC btw) using the cheap/easy composite mod sold by thefuturewas8bit but have had no problems with either TIA or Pokey sound.  Decent sound balance and everything works.  It's great to be able to play Commando finally!

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13 hours ago, marauder666 said:

Does it have a printed Atari logo on the top, or is it embossed?

 

Regarding audio, you should run the audio through 2 8.2k resistors from the right side on those pads on the board, connected together at one end to the wire going to the AV mod.  In fact 6.8k to 10k would be fine.  Ideally run the wire through a 1uf capacitor, unless thats on the mod.

 

Do you mean the Atari logo on the case? It's embossed (all of my 7800s are IIRC).

 

Audio: would you mind sending me a private message with an image so that I can see what you describe? Just conscious of not wanting to muddy the waters of this thread unless you think other people will find it useful?

I have a couple of other PAL machines with different mods in, so I'll check the DF with them when I get the chance, too.

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2 hours ago, ultrasteve said:

Do you mean the Atari logo on the case? It's embossed (all of my 7800s are IIRC).

Most are, just the one we had that exhibited the issues was a late printed one, just seeing if there are any patterns.

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8 hours ago, -^CrossBow^- said:

In the video I did on this, PPII was never an issue other than slight graphical glitching on the 7800 rainbow BIOS screen and occasional flickers of pixels that shouldn't be on the track selection screen. Otherwise the game itself was always fine. BallBlazer was the only game to actually cause the 7800 to lockup with any degree of certainty. And it was just luck really that I happened upon what was up. Anyway, @Trebor owns that 7800 used in the video now and unless he has been too polite to tell me otherwise, it has been working fine since I added that small cap to it.

 

My Pole Position II cart just gives a black screen 9 x out of 10, the times it does boot it usually corrupts like your video (but does not crash the system). I don't have Ballblazer on cart so no idea if that one works.

 

On my DF the only games I have had issues with are, Pacman Collection & Pacman Collection 40th Anniversary.

Pacman Collection - I started a game of Ms Pacman and the maze was the wrong colour, it corrected itself on stage 2

Pacman Collection 40th Ann - It crashed the system (garbage on screen) about 10 minutes into playing Pacman

 

I'll add that cap, it can't hurt to try!

Edited by Jouster

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30 minutes ago, Jouster said:

My Pole Position II cart just gives a black screen 9 x out of 10, the times it does boot it usually corrupts like your video (but does not crash the system). I don't have Ballblazer on cart so no idea if that one works.

 

On my DF the only games I have had issues with are, Pacman Collection & Pacman Collection 40th Anniversary.

Pacman Collection - I started a game of Ms Pacman and the maze was the wrong colour, it corrected itself on stage 2

Pacman Collection 40th Ann - It crashed the system (garbage on screen) about 10 minutes into playing Pacman

 

I'll add that cap, it can't hurt to try!

We tried it on the CPU end of the line on the PAL machine and it didn't work, going to try it on the cart end also to see if that helps.

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PAL machines strike yet again!

 

C64 fix for non running carts also doesnt do anything on ours.  I've suspected all along the PAL 7800 has board layout issues, its so different to the NTSC, doesnt have the big power and ground traces.

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51 minutes ago, juansolo said:

Most are, just the one we had that exhibited the issues was a late printed one, just seeing if there are any patterns.

No it wasn't, that was Muddyfunsters and that one works fine.

 

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30 minutes ago, marauder666 said:

No it wasn't, that was Muddyfunsters and that one works fine.

I have no memory... :D

Edited by juansolo

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I need a developer help!
I'd like Dragonfly to be able to display a startup screen that is similar to the sticker art. I am looking for a person who will convert this image to a .bin file. I have a project with layers from the "Krita" program, or I can export individual layers to .png files.
It is important that the startup screen looks correct on PAL and NTSC consoles.

 

Thank you in advance for your help :) 

 

 

dragonFly_2.png

Edited by rj1307
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Below is an example of how it will look like in 160B or 160b +

Mode 160b (13color)

I also tried in 160b+ but not much better (46 color)

edit:

I think it would be best to ask someone from Agenda to draw a nice pixelated drawing.

 

 

 

dragonfly_wide.png

dragonfly160b_wide.png

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6 hours ago, Eagle said:

I think it would be best to ask someone from Agenda to draw a nice pixelated drawing.

 

The artwork was created by @MotionRide and it is unlikely that I will have a problem redrawing it, but I need to specify the resolution and number of colors. Therefore, I am asking you to give me these values :) 
Do I have to pay attention to something to make PAL and NTSC work well? 

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@rj1307 A very quick conversion of the graphic you provided. I've tried to preserve the correct aspect during the conversion to 7800 pixels, not sure if this is what you are looking for?

 

This is a bit of a quick and dirty test and the graphics could do with some tidying to restore some of the detail lost in the down scaling to fit 160B, especially on the letters, but you get the general idea. Will work on both NTSC and PAL,

 

If it's useful, I can clean it up some more, or you can get someone to provide the graphics in 160x208X13 colours and I can recode that for you. Other options would be as Bobby said, 320B, but that's not a mode I have a lot of experience with, or 160B + with some trickery to have loads of colours. Not sure that would be much additional use in this example though. The colour matching squares need removing too.

 

Taken from BupSystem

image.thumb.png.3aa168c0515fc2a71218501084acffa3.pngdragonFly_2.png

 

DF_test2.bas.bin DF_test2.bas.a78

 

Edited by Muddyfunster
updated binary
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Thank you, I decided that the graphics will be created from scratch. If I understood correctly, it must have a resolution of 160x208 pixels and a maximum of 13 colors? 

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320B is two palettes, each one is BG plus 3 colors.  BG and color 1 cannot exist in the same bitpair unless you turn on Kangaroo mode (kill transparency).  When you do that, the characters basically behave like ANTIC 4 on the 8-bit Atari, but at high resolution.

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160B ... has two palettes of 12 colors plus BG.  So you actually get 25 colors.  Same with 160A but spread across 8 palettes each with 3 color plus BG.

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