looking for perfect 7800 Ballblazer emu

[WNivek]

Are there any Atari 7800 emulators out there which can play Ballblazer properly, complete with the jazzy title music and no graphical glitches?

 

For the most part, Prosystem is a great emulator, but it somehow manages to miss the cool part of the music.

MESS gets the music right, but the palette changes appear to be a few scanlines off, resulting in some irksome graphical errors.

 

Any suggestions?

[mimo]

wii7800 does the best job imo, but you need a Wii with Home Brew Cannel installed

[WNivek]

I do have a Wii with Homebrew Channel installed and Wii7800. Problem is, Wii7800 is itself a port of ProSystem. Sure, it's undergone some further development since then, but it still misses out the jazzy part of the Ballblazer music. Furthermore, it actually managed to regress a bit by introducing a couple of errant pixels/lines to the viewport, just below the horizon.

[GroovyBee]

Simple solution! If you like the game so much then buy a 7800 and the cart so you can play the real thing.

[WNivek]

I do legitimately own Ballblazer and a (long-since dead) 7800. That's how I know Prosystem/Wii7800 are failing to play all of the music - Ballblazer was easily my favorite 7800 game when growing up.

 

If I were to re-acquire the old hardware, I would likely either be burdened with having to use the original RF video output, or finding someone to mod the machine to accommodate composite video. (unless I had the good fortune to purchase a pre-modded system.)

Furthermore, it would require more space around the already-crowded TV, and a further set of wired, unwieldy controllers to be kept handy. While there is a certain thrill to be had in using the original hardware, emulation is much more convenient and less stressful on the wrists.

 

Just seems odd that the two emulators, being both open-sourced, haven't taken a peek at each other to correct their own deficiencies.

Edited July 4, 2009 by WNivek

[raz0red]

I do have a Wii with Homebrew Channel installed and Wii7800. Problem is, Wii7800 is itself a port of ProSystem. Sure, it's undergone some further development since then, but it still misses out the jazzy part of the Ballblazer music. Furthermore, it actually managed to regress a bit by introducing a couple of errant pixels/lines to the viewport, just below the horizon.

 

Wow, I didn't even notice that. I fixed it (I believe) and sent you a link to a pre-release version. I will do so more testing today on all the other ROMs prior to releasing it publicly.

 

As far as the sound goes, there are some definite issues with the current sound emulation of ProSystem. If I get some time this weekend, I will mess with it a bit and see what I can come up with.

 

Thanks.

 

--Raz.

Edited July 4, 2009 by raz0red

[WNivek]

Wow, I didn't even notice that. I fixed it (I believe) and sent you a link to a pre-release version. I will do so more testing today on all the other ROMs prior to releasing it publicly.

Awesome, dude! I've given it a shot and yeah, that appears to have done the trick for Ballblazer's errant pixels. Far as I can tell, graphically it seems perfect.

 

 

As far as the sound goes, there are some definite issues with the current sound emulation of ProSystem. If I get some time this weekend, I will mess with it a bit and see what I can come up with.

Cool, cool. I look forward to hearing of your results.

 

Thanks.

 

--Raz.

No man, thank you! It's great to see people who take pride in their work, setting out to deal with problems as they arise.

[raz0red]

No man, thank you! It's great to see people who take pride in their work, setting out to deal with problems as they arise.

 

Thanks for the kind words, but to be honest porting emulators and adding little tweaks is trivial compared to the amount of work it takes to write the emulator itself. The fact that the emulator works as well as it does is a testament to the huge amount of work Greg put into it along with the contributions of the devoted forum members (as well as the portions of open source code that have been integrated into it).

 

--Raz.

[Video]

It's problem is probably with emulating the Pokey, and there are only two games that use it (though more homebrews) so I imagine it's like FX on the SNES, it just doesn't come up enough. It'll be interesting to see it fully working though, but hell, even the 2600 emulators are still not perfect, so

[raz0red]

The problem is that ProSystem doesn't currently have SKCTLS (write) or RANDOM (read) implemented in the Pokey emulation. I added these to Wii7800 and all the sounds now appear to be present.

 

If anyone wants to test a pre-release version, just send me a PM. Otherwise, I will probably be releasing it this weekend after I get some decent testing in.

 

Thanks.

 

--Raz.

[WNivek]

Nicely done, sir.

 

What's odd, though, is that for some reason it doesn't seem quite like I remembered it. Granted, it's been a long time since I've played the real thing, so my memory could easily be a bit off, but I kinda wish I could do a side-by-side comparison against my old 7800 & Ballblazer cart.

 

Am I understanding correctly that one of the missing ops was a pseudo-random number generator? Out of curiosity, how close is your implementation to the original algorithm used in the hardware?

[raz0red]

Nicely done, sir.

 

What's odd, though, is that for some reason it doesn't seem quite like I remembered it. Granted, it's been a long time since I've played the real thing, so my memory could easily be a bit off, but I kinda wish I could do a side-by-side comparison against my old 7800 & Ballblazer cart.

 

Am I understanding correctly that one of the missing ops was a pseudo-random number generator? Out of curiosity, how close is your implementation to the original algorithm used in the hardware?

 

I used the implementation from the Atari800 emulator, so I am not sure how accurate it is. I will take a look at a couple of different implementations tonight (MAME, etc.) and see how they compare.

 

The other thing to note is that I didn't change the core Pokey implementation, I just added support for RANDOM. The implementation used by ProSystem is quite old and there are a number of newer revisions of it. I am going to upgrade it to incorporate the latest changes when I get a bit of free time.

 

--Raz.

Edited July 8, 2009 by raz0red

[Kr0tki]

I used the implementation from the Atari800 emulator, so I am not sure how accurate it is.

It is 100% accurate; it actually emulates the 17-bit/9-bit poly counter by calculating all possible values exactly like a real POKEY, and then storing them in a 128KB or 512B array to speed up performance.

I will take a look at a couple of different implementations tonight (MAME, etc.) and see how they compare.

Other implementations won't be more accurate, bu maybe they are faster, who knows.

[raz0red]

It is 100% accurate; it actually emulates the 17-bit/9-bit poly counter by calculating all possible values exactly like a real POKEY, and then storing them in a 128KB or 512B array to speed up performance.

 

Ah, very cool. I will run the emulator side by side w/ my 7800 and see if there are differences. It may be an issue with the way I implemented it, or possibly the current ProSystem Pokey implementation.

 

--Raz.