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What ATARI 2600 GAMES SOLD BY ATARIAGE DO WORK ON A ATARI 7800


Ryan Frazier

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You may have problems with melody enhanced carts on PAL machines... It's VERY hit and miss as to whether the 7800 will detect them or just boot straight into Asteroids. I have a machine that boots most of my homebrew but Star Castle Arcade only intermittently (maybe 1 time in 10). I've used another 3 PAL machines that won't boot any of them at all. You're fine with carts that are 'pure' carts though. Your best way for playing 2600 homebrew on a PAL 7800 is via a Harmony cart, they work just fine.

Edited by juansolo
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On 12/14/2020 at 2:45 AM, juansolo said:

You may have problems with melody enhanced carts on PAL machines... It's VERY hit and miss as to whether the 7800 will detect them or just boot straight into Asteroids. I have a machine that boots most of my homebrew but Star Castle Arcade only intermittently (maybe 1 time in 10). I've used another 3 PAL machines that won't boot any of them at all. You're fine with carts that are 'pure' carts though. Your best way for playing 2600 homebrew on a PAL 7800 is via a Harmony cart, they work just fine.

I have never had anyone else report this to me, and I've been selling many Melody games into PAL markets for years. 

 

Star Castle Arcade is not a Melody-based game, but uses our Aria board.  The Aria board uses a less advanced ARM chip, and it only uses it to support more complex bankswitching methods (such as those requiring additional RAM, like SARA-based games). 

 

I imagine if this was a prevalent issue, I would have heard it by now.  If anyone else has experienced this issue, I'd certainly like to hear about it.

 

 ..Al

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On 12/14/2020 at 12:45 AM, juansolo said:

You may have problems with melody enhanced carts on PAL machines... It's VERY hit and miss as to whether the 7800 will detect them or just boot straight into Asteroids. I have a machine that boots most of my homebrew but Star Castle Arcade only intermittently (maybe 1 time in 10). I've used another 3 PAL machines that won't boot any of them at all. You're fine with carts that are 'pure' carts though. Your best way for playing 2600 homebrew on a PAL 7800 is via a Harmony cart, they work just fine.

Harmony and Melody boards use the same basic hardware. And most of the enhanced games use the same microcontroller code as well. Are you sure these are Melody-based games?

 

As Al pointed out, Star Castle is an Aria-based game. It is probably the most complex Aria game available though, so even if there are issues with this game on certain PAL 7800s, it doesn’t mean all Aria games will have issues. As far as I am aware, there haven’t been complaints about other Aria-based games, as if there were then I would expect to have been asked to solve the issue long ago. 

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I've mentioned this before but one of my 7800s refuses to play champ games lady bug but other 7800s I own play it fine. I can't remember off hand if it was a 7800 with an expansion slot or not I'd have to check. Other than that I've had no issues with 2600 homebrews on 7800 hardware. 

 

I do know that I get a lot of what looks like rf interference with this and a couple other homebrews but that's a separate issue in a separate thread

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Star Castle is intermittent on mine (works very occasionally), Space Rocks doesn't work at all. Three PAL 7800's we tested at the time (mine, marauder's and muddyfunster's) mine was the most well behaved. Space Rocks and Star Castle wouldn't work at all on the other two. Galagon also works on mine but not on thiers. PAL machines can be a bit awkward/random it seems when it comes to detecting carts.

 

Mentioned a bit about it here:

 

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If certain PAL Melody games fail to boot on PAL 7800s, that is 100% fixable as the games work on Harmony. Just need to hand-hold the PAL 7800's "detection" routine (which clearly is error-prone!) until it wants to *actually* boot the cart.

 

The same will likely also work with Star Castle Arcade.

 

I personally do not have a PAL 7800, but I do have a NTSC one I modified to take a socketed EPROM, and I can certainly burn the PAL BIOS with Asteroids on there to see if I can replicate the reported issues, and if I can, I should be able to fix them.

 

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The only 'issue' I've come across with my (albeit small) selection of homebrew is with Chetiry which is a Melody game on my PAL 7800. It doesn't bother me in the slightest, and if it did I'd just play it on my 2600, but this is as good a place as any to document it.

 

When starting cold, the very left and right edges of the playfield waver like interference but this goes away on its own after a time. The more obvious thing is the bars of colour that appear in the same spot based on the colour of whatever is in one of two columns. If a piece is placed to the left over where the bars are it will have a black line running through it unless something is in one of the central spots to make it a different colour. Sometimes the bars don't appear, but I've only had that happen once or twice.

 

Nothing else in the game has anything off so I'm certain it's just a timing issue with the 7800 given the temperamental nature of 7800s barely being able to play 7800 games let alone enhanced 2600 games.

 

1524877921_ChetiryPAL7800.thumb.jpg.cbb0e20d4bc37ba7210e6951bfbfa790.jpg

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34 minutes ago, batari said:

If certain PAL Melody games fail to boot on PAL 7800s, that is 100% fixable as the games work on Harmony. Just need to hand-hold the PAL 7800's "detection" routine (which clearly is error-prone!) until it wants to *actually* boot the cart.

 

The same will likely also work with Star Castle Arcade.

 

I personally do not have a PAL 7800, but I do have a NTSC one I modified to take a socketed EPROM, and I can certainly burn the PAL BIOS with Asteroids on there to see if I can replicate the reported issues, and if I can, I should be able to fix them.

 

Harmony works without fail on all the PAL machines I've ever had pass through my mitts. When it detects Star Castle on mine it'll work flawlessly. My machine and Marauder's are the same revison yet his has much more trouble than mine. The PAL machine's detection circuitry is different to the NTSC one (you can't do the cap pull trick you can on the NTSC machine) so I'm not sure that'd be enough.

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3 hours ago, juansolo said:

Harmony works without fail on all the PAL machines I've ever had pass through my mitts. When it detects Star Castle on mine it'll work flawlessly. My machine and Marauder's are the same revison yet his has much more trouble than mine. The PAL machine's detection circuitry is different to the NTSC one (you can't do the cap pull trick you can on the NTSC machine) so I'm not sure that'd be enough.

The cart detection is a series of heuristics that are written into the BIOS code. They check values in cartridge memory space in an attempt to determine if a cart is present, and if so, what kind of cart. So, swapping in a PAL BIOS EPROM would run that cart detection on a NTSC machine. There are differences in circuitry of course and some other things, but running the PAL BIOS code is key.

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13 hours ago, batari said:

The cart detection is a series of heuristics that are written into the BIOS code. They check values in cartridge memory space in an attempt to determine if a cart is present, and if so, what kind of cart. So, swapping in a PAL BIOS EPROM would run that cart detection on a NTSC machine. There are differences in circuitry of course and some other things, but running the PAL BIOS code is key.

Gotcha. I tend to run 2600 carts on my 2600 also so it's no big issue for me.

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3 hours ago, hizzy said:

7800's with expansion ports might glitch with certain homebrews/2600 games. I get a glitch on pac-man 8k and HERO.

I’ve played both of those on my two examples of expansion-port 7800’s without issue using my Harmony Cart, and vintage H.E.R.O. cart as well. 

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21 hours ago, hizzy said:

I get this glitch with my expansion port 7800. None on my later model

 

 

I think your console has a problem independent of any hypothetical general problem with homebrew titles. Here’s PAC-MAN 8K on one of my expansion port 7800’s that has a UAV in it, played on my Harmony Cart. 
 

 

938DEFDE-FB68-4A20-B87F-3BBF084F3214.jpeg

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