Eight Bit Berzerk

[thegamezmaster]

Does this conversion play like the 5200 version where the voice talks while you're playing? Or do you have to press a button to hear the voice? Thanks.

[+Stephen]

There is voice throughout the game. It would be cool to have it re-coded so the action doesn't stop.

[thegamezmaster]

Thanks for the info.

[+therealbountybob]

On the menu I think you can press Option to hear the voices. Great game

[JamesD]

I kinda sucked at Berserk but I love the game. Simple but fun.
Wasn't this one of the carts that only works on the 400/800? I could be thinking of something else like Kangaroo though.

Edited December 14, 2013 by JamesD

[FULS]

Wasn't this one of the carts that only works on the 400/800? I could be thinking of something else like Kangaroo though.

This version by classics works on 800's and XL's.

Berzerk (Classics Fix Version).zip

[Level42]

There is voice throughout the game. It would be cool to have it re-coded so the action doesn't stop.

Yeah if that would be possible.... I just played this game on a NTSC 800 and man does this conversion come close to the original arcade game, and I know because I own one.

The behavior of the robots is really almost 100% identical to the arcade version. The only (but important) difference is that the robots appear and the action starts at the same moment. The arcade version gives you a few milliseconds to see where they are at a new level.

The voice sounds actually BETTER on the Atari, although it has a much more limited vocabulary. That would be something that could easily improved by now, with extended memory etc. I have a full list of all the words that Berzerk uses. (some you hear VERY rarely on the arcade machine).

 

I can NOT understand that this game was never officially released, it is the best home conversion for sure. Overall I have a feeling that the guy(s) who programmed this had access to the "rules" that the arcade game robots follow. I would love to know who programmed it and here the story behind it, also why it was never released.

[+Ripdubski]

I read many times it was one of the games that saw prolific pirating before the actual release date and thats why it was never released.

[Tempest]

I read many times it was one of the games that saw prolific pirating before the actual release date and thats why it was never released.

That could be the reason. I always assumed that it was because Atari wanted to give the 5200 a few arcade exclusives so Space Dungeon, Battlezone, Mario Bros, and Berzerk were never released for the 8-bit. I'm still not sure if the roms for Berzerk and Mario Bros are official 8-bit protos or just 5200 hacks. I believe there's a box for Mario Bros in one of the CES pictures and it has a known part #, so that one was probably planned as an official release.

[Lynxpro]

Speaking of the 5200, has anyone ever hacked an A8 to use the 5200's joystick ports and associated hardware?

 

(Ducks )

[Kr0tki]

I'm still not sure if the roms for Berzerk and Mario Bros are official 8-bit protos or just 5200 hacks.

The Berzerk ROM image definitely doesn't look like a 5200 hack, for 2 reasons:

1. It's a ROM image, while all 5200 hacks are DOS binary files.

2. 5200 hacks are created by changing bytes in the original 5200 ROM and appending additional code. In case of Berzerk, binary comparison with the 5200 ROM reveals differences more substantial than that - if it was a hack, it would have to be created by disassembling the 5200 version first, and that's unlikely.

 

As for Mario Bros., all verisons I've seen are DOS binary files by Glenn the 5200 Man; I'm sure I mentioned that to you before.

[Level42]

So.......then Berzerk was leaked by Atari people ? It happened with Behind Jaggi Lines too of course so it sure is possible.

 

I seem to remember that I had to run Translator to play the copy of Berzerk that I had BITD, but the one I just got on one of the floppies that came with a set I just bought plays fine on XLs.

 

I would _LOVE_ to see an update to Berzerk. The only thing needed would be adding some words because the A8 version has less text than the arcade. (Would love to hear it say "Coin detected in pocket" in the attract screen.

 

Does anybody know who programmed it (the 5200/A8 version) ? Would it be possible to reverse engineer how they did the voice ?

[Synthpopalooza]

If I am right, the voice was done by using an odd numbered distortion on one (or all) of the POKEY AUDC registers, and by messing with the volume setting on the corresponding AUDF registers. Done really fast (at 60 cycles per second on NTSC) this allows you to have 4-bit sampled sound. Only downside is, it can't be done in the background (like in a VBI) far as I know.

[Rybags]

Forced volume output, aka digital playback as per anything else that plays samples.

 

"Really fast" actually = like 2,000 times per second. Berzerk I'd guess is at least 4,000/sec, it's been a while since I've had it loaded up.

 

How the samples are stored, I've not looked. Simplest way is to pack 2 samples per byte but it becomes memory hungry.

 

On the other hand, if it uses some compressed method like Impossible Mission on C64, then working out the method could be a real chore - I've looked online to try and find the method IM on C64 uses but there's next to no information. It would seem the method is sufficiently good that it's still a viable method today and not made public.

 

The real bitch about 4-bit samples is that compression methods that are easy to employ and work well on 8 or 16-bit samples don't translate well down to 4 bits.

[tschak909]

Yes, there is not enough cycle time to be able to handle animation and the sound at the same time, as is mentioned above, the sound is made by amplitude modulation (altering the volume registers in real time)...

 

Normally, this is done with ANTIC off, so that DMA doesn't eat away too much cycle time (at the expense of the display)

 

Given the "computerish" sound of the voice in the first place, the distortion from the DMA cycle stealing actually adds character to the sound...

 

Now, those of you who say, "BUT the MyIDE video player has sound! the video play..."

 

yes, I know... but if you study the code of each respective player, virtually _EVERY_ single possible cycle of processor has been optimized, with no cycles left...we can't do that here without drastic rewrites to the game (and arguably, throwing away the game...)

 

...but if someone wants to try... go for it.

 

-Thom

[Rybags]

I forgot to mention the time factor.

 

The old belief was that sample playback be done in the foreground with delay loops and in some instances turning off the screen.

 

The modern way is use Pokey Timer IRQs - that allows foreground processes to still be active and thanks to the precision of the Timers, leaving the screen turned on has minimal effect on the playback quality.

 

Check Space Harrier as an example of the modern method - the voice + music is active and the action doesn't stop.

[+Stephen]

Exactly - Rybags beat me to it. I was going to site Space Harrier as the "new way" of doing things. It is amazing to see (and hear) the little Atari doing full screen animation with full quality sample playback at the same time!

[Drummerboy]

Sometimes i dont hear the firing SFX.

[_The Doctor__]

That could be the reason. I always assumed that it was because Atari wanted to give the 5200 a few arcade exclusives so Space Dungeon, Battlezone, Mario Bros, and Berzerk were never released for the 8-bit. I'm still not sure if the roms for Berzerk and Mario Bros are official 8-bit protos or just 5200 hacks. I believe there's a box for Mario Bros in one of the CES pictures and it has a known part #, so that one was probably planned as an official release.

but I have a battlezone cartridge that I bought at clover.... it's a grey XE cart

[Tempest]

but I have a battlezone cartridge that I bought at clover.... it's a grey XE cart

Different version. Later on in the XE's lifespan Atari decided to create a completely different version of Battlezone and release it on the XE. I believe that version is 64K while the original is 16K. They're very different ports.

[peteym5]

I discovered with digital sounds IRQ, it is best to write a custom IRQ and NMI routines. That requires disabling the OS ROM and use the RAM under. You have much more CPU time available to be able play digital sounds with a moderate size VBI for your game.

 

I have been considering doing "FRENZY" on the Atari 8-bit because I have experience working with Digital Sounds, Character Mapped Screens, and Sprite Multiplexers. We could do a very accurate port. PACMANPLUS did this game on the 7800 and feel we can do the same for the 8-bit/5200. Might use Antic-4, but the arcade seems to have more "Rows and Columns" for those pieces of walls you have to shoot. I can do some character set manipulation to get it close to what the arcade is. Since it also has steady a playfield, "Super-IRC" could be used if we need to go over 5 colors.

[Rybags]

Of help in all cases is have the Timer IRQ as the only possible IRQ source - that means that no testing is needed as you already know where it comes from.

 

The trick with VBlank is to take the whole thing over and get IRQs enabled again as quickly as possible.

But the problem arises when VBI occurs when the IRQ is partway through being serviced. You can't enable IRQs in this case as there's danger of the IRQ triggering a second time.

Problem 2 is if you quit the VBI then you lose that processing that a game or demo otherwise needs.

 

A way around that can be to use the Serial Output Complete IRQ - it can be used as an "on-demand" IRQ since it will trigger instantly so long as serial data isn't being sent. It can be used to allow the Timer IRQ to finish up, then get control back to your VBlank code.

[Ransom]

Different version. Later on in the XE's lifespan Atari decided to create a completely different version of Battlezone and release it on the XE. I believe that version is 64K while the original is 16K. They're very different ports.

 

You know, I've owned both for years and didn't know that. Battlezone's never been all that interesting of a game to me, so I haven't played either of them much.

 

Is one significantly better in terms of game play than the other (a la the two versions of Dig Dug)?

[Tempest]

 

You know, I've owned both for years and didn't know that. Battlezone's never been all that interesting of a game to me, so I haven't played either of them much.

 

Is one significantly better in terms of game play than the other (a la the two versions of Dig Dug)?

Eh, they're both kinda crappy in their own way. The XE one has more arcade like graphics (the background is vector like the arcade), but it doesn't play much better than the original 5200 proto. The 5200 proto has some serious flaws, but was impressive for the time. The XE version is the better one to play I suppose, but both could have been better.

[Ransom]

Eh, they're both kinda crappy in their own way. The XE one has more arcade like graphics (the background is vector like the arcade), but it doesn't play much better than the original 5200 proto. The 5200 proto has some serious flaws, but was impressive for the time. The XE version is the better one to play I suppose, but both could have been better.

 

That's too bad. I guess I'll stick with Robot Tank, then.

 

(Nice to learn something new, though. Thanks for that!)