D.K. VCS

[+swlovinist]

I actually passed up on the Atari portable for this exact reason. Bitd stuff like Galaxian and Berzerk (which don't even use special bankswitching hardware) not playing properly is unacceptable.

 

Berzerk has a slight workaround from what I hear. I understand anyone who does not pick this up due to games not working. I look at the extra games working as a bonus.

[+evg2000]

 

Berzerk has a slight workaround from what I hear. I understand anyone who does not pick this up due to games not working. I look at the extra games working as a bonus.

What's the work around?

[Keatah]

I actually passed up on the Atari portable for this exact reason. Bitd stuff like Galaxian and Berzerk (which don't even use special bankswitching hardware) not playing properly is unacceptable.

 

Could that have been done on purpose? Maybe there is a simple mod to the binary image to fix it?

 

[Trebor]

I actually passed up on the Atari portable for this exact reason. Bitd stuff like Galaxian and Berzerk (which don't even use special bankswitching hardware) not playing properly is unacceptable.

 

I'm with you. Third party games from XYPE, Tigervision, could be overlooked.

 

But Activision games like MegaMania, River Raid II, etc.; Parker Brothers releases of Q*bert, Super Cobra, etc.; and especially the popular first party titles, as you mentioned, that's some major oversight and issues.

Last thing Joe needs to be concerned with is making DK VCS work under such flaky simulation.

[Keatah]

True enough. Games should be written for their target hardware. Target hardware that was sold in the 70's. Emulator Stella still has several incompatibilities. But the authors of Stella will eventually make changes to the emulator, not the games!

 

In apparent contradiction to what I said in post #803, as long as DK VCS works on the real VCS we're good to go. In post #803 I was thinking about a single-byte patch or something.

[iesposta]

I remember reading that the technique found by the programmer for 2600 Galaxian to have 7 horizontal sprites that did not flicker was so good that he had it patented?

 

Anyway, if not true it is that 7 sprite hardware trick that's the reason it fails on the Porrable.

True enough. Games should be written for their target hardware. Target hardware that was sold in the 70's. Emulator Stella still has several incompatibilities. But the authors of Stella will eventually make changes to the emulator, not the games!

 

In apparent contradiction to what I said in post #803, as long as DK VCS works on the real VCS we're good to go. In post #803 I was thinking about a single-byte patch or something.

[Andromeda Stardust]

 

Could that have been done on purpose? Maybe there is a simple mod to the binary image to fix it?

 

I am wondering if Atgames applied patches to the affected games instead of fixing the emulator? Does the Atari portable have glitches in game ROMs loaded through the SD slot that don't exist in the built in versions? That would indicate evidence of "fixes" applied as ROM patches...

 

Oops, not an Atgames thread!

[doctorclu]

 

 

I'm with you. Third party games from XYPE, Tigervision, could be overlooked.

 

But Activision games like MegaMania, River Raid II, etc.; Parker Brothers releases of Q*bert, Super Cobra, etc.; and especially the popular first party titles, as you mentioned, that's some major oversight and issues.

Last thing Joe needs to be concerned with is making DK VCS work under such flaky simulation.

 

 

Making Joe? No one is making Joe do anything.

 

Hey despite flaws I think the Flashback Portable (FBP) is a cool little device. The fact that you have a little game system and for the first time SD support, that is a lot of fun.

 

DK VCS was a cool Donkey Kong project. The part of DK VCS that works on the FBP is already really cool.

 

This is just me saying "Well here is what works if curious." If he knew of a work around, awesome, if not, it is what it is.

 

What's the work around?

 

Best work around I found is some of the other fan hacks out there. Some work better than others.

 

I am wondering if Atgames applied patches to the affected games instead of fixing the emulator? Does the Atari portable have glitches in game ROMs loaded through the SD slot that don't exist in the built in versions? That would indicate evidence of "fixes" applied as ROM patches...

 

Oops, not an Atgames thread!

 

That doesn't seem to be the case. I've tried the game roms and the internal game version, like Astroblast, and the games are the same.

 

One thing I will have to say for Atgames and they even said the same, they made an emulator that works with the 60 games they intended for release. As you know, there are hundreds of games that can potentially be played through the SD card support. As I write this 543 games have been tested on the FBP. 393 are playable without flaws. 60 of those were intended to work, so 333 games that work without trying. Not bad. Also makes this the Flashback that can play nearly 400 games, and those with Flashback Portables have another listed 300 games to try out.

 

45 are playable with flaws.

(1) of a 32 in one game cartridge only loads one game.

(5) Gameplay related.

(6) Screen jitters.

(4) Prototypes

(29) Some screen glitch

 

There are 105 are not playable for various other reasons such as:

(34) dpad is unresponsive. These games generally load and player otherwise so close.

(12) a two player game on a one player system.

(17) Needed a different controller. This one if you find the joystick hacks on Atariage make Omega Race, and some of the Seseme Street kiddie games (Big Bird's Egg Catch, Cookie Monster Munch, Holey Moley) workable.

-Non-emulated hardware that causes a outright crash.

----( 8 ) No content on screen (though you might hear sounds)

----(7) Gameplay related

----(2) Special hardware required.

----(20) Just crashes.

(5) Prototype

 

Other interesting point is comparing the compatibility list of the Flashback Portable to the last time the Flashback could load external games, the Flashback 2, the list of games that didn't use to work verses those that do now have greatly improved.

list.xls.zip

 

So for a commercially released system that set out to make an emulator that worked with 60 select games, they made a system that did that and way more.

 

Just not DK VCS, which is a bummer because it is looking pretty cool.

Edited November 20, 2016 by doctorclu

[RevEng]

Last thing Joe needs to be concerned with is making DK VCS work under such flaky simulation.

Making Joe? No one is making Joe do anything.

Syntax error. The predicate in Trebor's sentence is "Joe" and he's the one doing (or not doing) the theoretical making.

 

We've seen this flawed emulation issue before, when people added cart slots to Flashback 2 and found it couldn't handle undocumented opcodes and on-cart ram. Some FB2 owners wanted homebrews to be modified to avoid behaviors that would make them incompatible with FB2. And I've heard that if you go back even further, some homebrewers would spackle over flaws in PC based emulation.

 

It's a healthier situation all around to get the flaws in the emulator fixed, or failing that, the company that produced said emulator gets complaints and understands that near-perfect emulation need to be the goal.

 

If homebrewers spackle over flaws, it gets in the way of that progress. Even worse, the subset of 2600 functionality we homebrewers can use will be further restricted every time a new flawed emulator comes out.

 

My 2 bits, anyway.

[+swlovinist]

What's the work around?

 

The screen is glitched, but if you can move around it stops being glitched from what I have heard. I have not tested it out myself.

[Keatah]

It is important that emulation get fixed before any roms get modified. Game devs are thoroughly into exploiting tricks and such to push the boundaries of what is possible on the VCS. Gone are the days of simple 2k and 4k games. And it is emulation's duty to keep up and always strive to match the original hardware as best as possible. Some emulators do this very well. Others not so much.

[Andromeda Stardust]

It is important that emulation get fixed before any roms get modified. Game devs are thoroughly into exploiting tricks and such to push the boundaries of what is possible on the VCS. Gone are the days of simple 2k and 4k games. And it is emulation's duty to keep up and always strive to match the original hardware as best as possible. Some emulators do this very well. Others not so much.

This is eerily reminiscent of the early days of NES homebrew where emulators were still crap and flash carts did not exist, and public knowledge of how to assemble an EPROM cart was lacking.

 

As a result, many early homebrews did not run on actual hardware, or more accurate emulators like FCEUX which came along much later. Most of the good ones have since been fixed to run on repros, flashcarts and modern accurate emu. N64 hacking/emulation is in a similar state. Real hardware cannot pull data pointers indexed at odd values, and as a result 99% of Super Mario 64 and numerous other ROM hacks are 100% broken when run on an N64 Everdrive. I'd kill to play some of these excellent community hacks on real hardware, but the author of the hacking tools is reluctant to fix them or release the source.

 

But I agree patching ROMs to run on crappy emu is not something the community should waste it's time with.

[Zonie]

Scrolling. Brilliant. This plays awesome. Where were you in 1980???

[doctorclu]

Just got a Harmony cart mainly to try out this and a few other games. Amazing work.

 

(Goes and plays it some more.)

Edited January 25, 2017 by doctorclu

[Jumpman1981]

This Is Amazing! Are You Planning On Doing Any Others?

[Nukey Shay]

DK VCS is playable on the AFP by configuring SARA ram as $FF's in the binary. There are some other issues, but it looks and plays fantastic!

 

///station break///

Pretty much the *only* problem in Berzerk was the player sprite collision with his own missile (Bit 6 of CXM0P) - touching your own missile deactivates it. This was needed for the "rebound" variations of Otto, where he is shootable. Otto shares the same sprite as the player...and missile positioning is slightly off for that portion of the screen for some weird reason. So the actual workaround is to remove the BVS branch so bit 6 won't trip the disable routine.

///back to DK discussion///

[atarifan88]

DK VCS is playable on the AFP by configuring SARA ram as $FF's in the binary. There are some other issues, but it looks and plays fantastic!

 

Is there a modified rom available with this fix?

 

Edit: found it!

Edited February 4, 2017 by atarifan88

[Joe Musashi]

Here you go.

 

Very cool! I guess I could change the padding bytes to $FF, but I fear it might break the auto detection in other emulators. Stella seems fine, though.

[doctorclu]

Love DK VCS. Glad it is working on the Atari Flashback Portable.

[Zonie]

AMAZING. Flattening the girders instead of angles is almost invisible. Doesn't affect gameplay at all...

Edited February 23, 2017 by Zonie

[Joe Musashi]

I've had some free time to go through my final checklist:

 

Not much had to be changed, there are only a couple of minor fixes compared to the latest release candidate RC3.

• The boot screen message is delayed for half a second to give CRTs time to sync.
• PAL colors for the title rainbow effect have been slightly altered.
• ADSR sound curves of the intermission tune have been improved a little (should avoid some clicking noises).
• Fixed a bug where Mario would accidentally jump at the start of a stage.

And with that I am happy to present the first "official" release 1.0

 

D.K.VCS_1.0_170304_NTSC.bin

D.K.VCS_1.0_170304_PAL60.bin

 

So, I guess that's it. In case further bugs are found, I'm still going to do service releases. Also a Pauline version is planned. Other than that I'm moving on to new projects. I've been talking to Al about a cart release, but that's all that can be said at this point.

Of course all this would not have been possible without the help and support of many people. Particularly, I would like to thank LS_Dracon for coming up with the initial inspiration and many suggestions that lead to making this game. Also, I'd like to thank Omegamatrix, tep392, Thomas Jentzsch, iesposta, Kosmic Stardust, raindog, roland p, cd-w, PacManPlus, roryjr, pac_man_fan, MeneerJansen, Turbo-Torch, VectorGamer, Random Terrain, save2600, KAZ, and Arenafoot for all their help.

 

Last but not not least many thanks to stephena for Stella, and Albert for AtariAge.

 

See you in the next game!

[Albert]

Congratulations!! I look forward to testing this out, and just in time for the weekend!

[+save2600]

I'll give the latest version a try later this weekend, thanks for all the updates and sticking with it!

[Skippy B. Coyote]

Most awesome! I'll be really looking forward to testing it out this afternoon. The only change I could have suggested for the final release was to make your score stay on the screen until a new game was started, so people to could take and share pictures of their scores for the High Score Club, but other than that it seemed perfect and ready for a cart release. Fantastic job once again!

[Tempest]

Holy moley! This is impressive! I never thought the 2600 was capable of something like this.