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My experiments with Atari 7800


Eagle

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5 hours ago, Defender_2600 said:

 

In short, MariaECI is a FPGA of 7800 MARIA graphics chip that enhances the original graphics performance with more palettes in 320 mode, full transparency, more sprites on screen and much more. It currently runs on Atari 8-bit XL/XE and is planned for 7800 MiSTer. Obviously it is hoped that in the future it will also be available for 7800, perhaps with the SN³ cart. But I'm not the right person to answer these questions.

That sounds like it would have issues with compatibility. It would be such a bummer if new 7800 games only ran on the mister.

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On 8/11/2023 at 8:01 PM, Eagle said:

For example we have YM2151 for few years for now and no one is using. ... ... No chance to get very good music in game. ... ... Instead of YM2151 we should use YM2413, but someone decide long time ago to put YM2151 in XM module 

 

1 hour ago, Bakasama said:

I was there way back when XM was going to have just a Pokey. Somebody argued for adding the YM2151 to the XM. If the issues with YM2151 using another coprosessor were addressed a bit earilier, maybe the XM would use a different soundchip.

 

The YM2151 has been used by Atari in some arcade games, starting with Marble Madness in 1984, so the choice for XM was motivated by historical value, thinking about what Atari could have used in 1984/1986 for the expansion module.

 

The recent "Pac-Man Collection 40th Anniversary Edition" has made excellent use of the YM2151:

 

Another masterpiece, 7800 "1942" with YM2151 sound:

 

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10 hours ago, Defender_2600 said:

The YM2151 has been used by Atari in some arcade games, starting with Marble Madness in 1984, so the choice for XM was motivated by historical value, thinking about what Atari could have used in 1984/1986 for the expansion module.

:thumbsup:

512 Arcade games utilize the YM2151.  Any who are interested, the link provides a plethora of songs for reference, all sorted by Arcade title. 

As mentioned in other threads, availability and cost were considerations too.

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  • 2 weeks later...
  • 2 weeks later...
On 9/9/2023 at 1:47 PM, Eagle said:

You can make your own. Will be open source. 

MariaEci:

 

E255B72D-E133-4F1D-9EC4-FAB4C7B57CB1.thumb.jpeg.4339d2ef499c34774b261fa29e9abad0.jpeg

 
 

 

 

 

 

This look something Atari was planning with the laser disc player back on the day.  Now, if you have pre rendered background to scroll, demonstrating the potential the 7800 had.

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  • 2 weeks later...
1 hour ago, Eagle said:

160B mode background plus 32 sprites (12x32) in 13 colours. 

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And this is about 25% what MariaEci can do :D 

 

 

 

Excellent job! :)

 

If you like it, you can use my 160B - 12 colors background of Bomb Jack (128 pixel wide), it is very close to the arcade version and it has detailed and clean graphics. I also added a third green color to enhance the trees. Below, I attach the 7800 graphics. It is ready with square pixels.

 

 

7800backgroundofBombJack160B.thumb.PNG.b0253e8df176abe1ef119ecc85457c21.PNG

 

 

* there it is:

7800backgroundofBombJack160B.PNG.b52306da2f6b00afe1008f3800956504.PNG

 

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MariaECI is very interesting, especially because it is an external device (everybody can use it), it has a SD card and RGB output and new awesome 7800 games could be ported to A8.

I know it's a completely different graphic architecture, but how would you compare it to VBXE?

Would it be possible a MariaPBI?

Thanks!

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Hi, 

 

I am looking for programming information on Maria. Have been searching and splicing together what I have found. I have these questions, wanted to see if someone could help?

 

1) Where is a good source for detailed Maria operations?

2) When handling a display list for a zone, does each sprite have its own display list with a palette selection, or are all the sprites combined in one list? 

3) Does Maria recreate (DMA) all the data into a smaller zone buffer, just before it scanlines out the zone? Is this a temporary storage location, or is there memory for all the zones?

4) If there is a graphics buffer, how many bits per pixel are stored? Why would it need this, if it always DMAs just before rendering?

5) Since there is a double buffer, this implies there is storage for one complete frame, what is stored in there, since there can be many combinations of palettes per sprite, because 2 bits per pixel would not be enough.

6) Last, is there a Discord site for 7800 programming?

 

The best I found was: http://7800.8bitdev.org/

 

I guess there is a direct and indirect mode. So, in direct 160x2 you are limited to 4 colors per pixel, however how does this tie into the sprite DLL ability of Maria, is this a parallel event? if so then the double buffer mode is only for direct mode, i guess.

 

Thanks.

Confused 

 

 

 

Edited by eed002
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On 9/24/2023 at 10:13 PM, Defender_2600 said:

* there it is:

 

MariaECI can have extra 320x240 background in 256 colours

 

13 hours ago, Philsan said:

Would it be possible a MariaPBI?

 

Yes.

 

13 hours ago, Philsan said:

I know it's a completely different graphic architecture, but how would you compare it to VBXE?

 

I don't want to reveal too many details. But on top of graphics you will have very powerful music card and ram extension (32MB in 256KB blocks)

5 hours ago, eed002 said:

6) Last, is there a Discord site for 7800 programming?

 

AtariAge discord (Homebrew-chat) or AArea if you speak Polish :D 

5 hours ago, eed002 said:

The best I found was: http://7800.8bitdev.org/

 

This is good source.

 

https://github.com/tebe6502/Mad-Assembler/tree/master/examples

 

7800 Basic as well.

BTW, one of the people involved in this project managed to run the 7800basic code on MariaEci :D

 

 

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