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Dark Chambers to Gauntlet Conversion

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This project began as an effort to modify Dark Chambers for the Atari 2600 in the direction of the arcade game Gauntlet (Atari 1985). What started as a few graphics changes and minor modifications to game play slowly evolved into a full 32k conversion, thanks to a good disassembly and especially Adam Clayton’s phenomenal Dark Chambers engine for the VCS.


The game is now complete, with the following features:


* Play all 4 characters from the arcade, in a 1-player game or in any 2-player combination

* Each character starts with a special ability:

Warrior: extra shot power

Valkyrie: extra armor

Wizard: extra magic power

Elf: extra shot speed

* Fight 3 levels of ghosts, grunts, demons, and sorcerors; 2 levels of generators and bones; and death.

* collect food, treasure, keys, and magic potions

* increase your abilities with 4 different upgrade potions as well as invisibility amulets

* play 80 unique levels, including the first 7 modeled on the arcade intro levels


Final versions

NTSC: Gauntlet (Atari 1985).bin

PAL: Gauntlet (Atari 1985) PAL.bin

SECAM: Gauntlet (Atari 1985) SECAM.bin








Earlier released builds:








Original post (May 12, 2015):


I recently introduced my kids to Gauntlet, and that got me thinking about hacking Dark Chambers so they could play on my VCS.

So here's a start on a conversion.


I started with the sprites naturally but quickly realized the animation tables needed reworking, as the sprites were shared in weird ways. Reducing the animation frames for players and enemies gave me enough room to shoehorn in a whole bunch of new sprite and color data. All four characters are now coded in. However, I haven't figured out a way to switch between them within the game. So I've uploaded two versions, WW for the Warrior and Wizard and EV for the Elf and Valkyrie. As it stands, you'll have to do a bit of hacking to get the exact P1/P2 combination you want--I hope to post some instructions on that later. There are no special characteristics per character, so it's just visual.

Enemies have been changed to grunts, ghosts, demons, wizards, and death. They no longer mutate form, and instead of disappearing on contact they continue to melee attack as long as they are touching you (but you can't melee back). Ghosts, however, do disappear and take a chunk of health in the process. Wizards blink in and out, and death now can only be killed by magic. Making demons and wizards shoot is not likely to make it into this hack--just way too complicated.

One thing that makes Gauntlet really different from DC is how enemies mass up behind each other and beeline straight toward you if nothing is blocking them. DC is very different: enemies can overlap and tend to amble around. But after a couple of experiments I'm hesitant to change this. Overlapping sprites all beeline to the same spot and appear as a single enemy if there isn't some kind of coarse movement grid checked against. So this part of DC has been left as is.

Dark Chambers draws levels with a pretty remarkable economy of code. There are 16 playfields actually drawn out in pixels; each DC screen allows you to scroll up and down through a stack of 4 playfields, each represented by one nybble. So the original map for Level A was set in just two bytes: $40, $19. But the flip side of that economy is that it just isn't possible to reproduce intricate mazes. Instead I just redid some of the playfields to get a bit of a Gauntlet feel in here, with obstacles, diagonals, nested boxes, vertical lines, and generally narrower spaces. Levels 1 through 7 have been completed so far, and I tried to port the corresponding Gauntlet levels over in spirit. Levels 8 to 26 haven't been finished yet--these will be mostly new creations although drawing inspiration from various Gauntlet levels.

I know there are complaints about the pacing of Dark Chambers. I wonder if a lot of that can be mitigated by not having the player double back too much, and by increasing the number of enemies. Player speed and scrolling speed can be increased without too much trouble in DC, but the problem is, that introduces a number of glitches that would have to be fixed. For the moment, I just kept everything as is.

Overall, I know we're still a ways from Ed Logg's arcade masterpiece, but if you are craving a Gauntlet experience on your VCS, or just want a new take on Dark Chambers, here's hoping this can tide you over.




UPDATE October 7, 2015


I've been able to make a great deal of progress since the above was posted. We're now close to a finished Gauntlet for the Atari 2600. The latest version is posted below, please see the rest of the thread for earlier versions and running commentary on what was changed.


A summary of the game so far:

* Play as all 4 characters from the arcade, either as 1 player or in any 2-player combination
* Each character starts with a special ability:
Warrior: shot power
Valkyrie: shield
Wizard: extra magic power
Elf: shot speed
* Fight ghosts, grunts, wizards, and death as well as generators and bones
* collect magic and upgrade potions
* 80 different levels

Edited by CDS Games
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  • 3 weeks later...





The extra Dark Chambers treasures have been replaced with Gauntlet items:
* doors can now be horizontal as well as vertical
* bones (ghost generators)

* cider (increases health, looks almost the same as poison)
* redid generator sprite



And there are two major changes to game play:

* The side exits are now gone. I'd like to try making every level just one screen, but we'll have to see how that works out. This build is only partially playable until the level patterns and the item positions are redone. Oy. Big job.

* You now move twice as fast, and some of the enemies are sped up as well. Finally was able to iron out the scrolling bugs, so here's your chance to see what a faster Dark Chambers is like. :)

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Thanks roryjr! I still have graphics work to do but for now I'm concentrating on mechanics and fixing bugs.


Here's a new update, now playable to level 8. Also patched in some music between levels because it just didn't feel like Gauntlet without it.




These single-screen levels seem to be working well, so I'll continue along the same lines. That could well give us 80 quick levels instead of 26 long ones.

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  • 2 weeks later...

CDS, there's a trick in programming Gauntlet. The monsters are NOT sprites.. they're part of the map tile set.


You mean in the arcade right? Makes sense. But since this is a hack and I'm no programmer, I'm stuck with the existing kernal, which uses sprites and does a very good job with them in terms of minimizing flicker, etc.


Anyone's free to try new tricks from scratch (and actually, I'd love to see that). I've wondered myself whether you could use NUSIZ to put more sprites on the screen.

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I've been working from the source code actually...and it's the only reason I've gotten as far as I have. :) Didn't realize it was Curt though who released it, so thanks Curt!


I'm not one to turn down any help at all, but the whole idea behind this is to be a simple conversion. The easier the conversion, the more likely it is to get done.


And frankly I'm not sure how using the VCS's playfield would make a better Gauntlet, if that's the idea here. Omicron is a fantastic implementation of the hostile playfield concept...but it's all blocks.


Dark Chambers already has a pretty elegant way to put lots of sprites on the screen and minimizing flicker, so I'm quite happy working within those parameters.

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Thanks! Programmed from the ground up it could have been really something.


Likely Atari thought of it, but I'm guessing their settlement with John Palevich on Dandy had something to do with the decision to go with Dark Chambers instead. I wonder whether a Gauntlet port was ever discussed in house.


By the way, this November is the 30 year anniversary of Gauntlet's release.

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This is a bit messy, sorry. Lots of things still need cleaning up but I haven't been able to devote much time to it lately.




* New levels added--I think you can get to level 20 or so.
* Redrew title screen graphic
* Got rid of the room entry table and made levels progress in an increment.
* Replaced it with a table for playfield and background colors. Levels 1-7 as shown above, and then colors repeat every 8 levels.
* Scoring changes:
Grunts, demons, sorcerors: 10 points shooting, 10 points magic.
Ghosts: 20 points shooting, 10 points magic.
Death: 0 points shooting, 1000+ points magic.
* Added or changed sounds for keys, treasure/food/potions, and exit

Oh, and an experiment--starting out with the shot power upgrade. That was my attempt to work character abilities into this..lame as it is. :)

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  • 3 weeks later...

Latest version: gauntlet710a.bin


Didn't like the old grunt sprite so that has been redesigned. Cleaned up the title screen also.

But the big news is that the 4 different character classes are almost implemented in game. Argghh....so close! On the title screen, pressing select will cycle you through each character (Warrior, Valkyrie, Wizard, Elf), first alone as 1 player and then as various 2 player combinations.


When you start the game, health bars and scores are then colored based on your selection. Three of the characters even start out with a power upgrade (no potion needed) as special abilities:

Warrior (shot power); Valkyrie (shield); Elf (shot speed)

I'm hoping to give the wizard an extra power elsewhere (like the ability to take out generators with magic, which the other characters will then lose).

But the huge issue right now is that I don't have two extra animation tables for the wizard and elf, and because of the way the program works there isn't an easy way to shoehorn them in either. I'm trying to sort that all out, but in the meantime, the wizard just uses the enemy sorceror sprite (in only partially visible purple) and the elf uses the grunt sprite. More minor, but still annoying, is that the 2nd player doesn't appear in some of the variations.


If any of the programming/hacking gurus are reading this and have any suggestions, I'd love to hear 'em.

Edited by CDS Games
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  • 2 weeks later...


Ok! All 4 characters are now fully implemented and selectable in any combination. And the wizard now has his own special ability--he starts with a full load of potions.

I couldn't figure out a way to add extra animation tables, so I had to drop one enemy and share the player wizard and enemy wizard sprites. Small price to pay though for four working players, I think.

Other changes:

* Level counter now implemented with 2 number digits. Should be able to count to 99 now.

* All games now start on Level 1

* Bug fixed on 2-player games: all character combinations now work correctly

* Changed the potion use sound

* Potions no longer take out generators or bones (too easy!)

Any interest in having this on a cart? I'm thinking a silver label 30th Anniversary edition with the C64/Atari computer artwork:


Edited by CDS Games
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