Draco-DS - A Dragon / Tandy CoCo Emulator

[wavemotion]

Huzzah!

I found the problem with some 64K games like Sailor Man. Turns out the vector table in the ROMs is still always visible to the SAM for vector handling... and the only 64K games that were working are games that don't directly require an interrupt vector (some games just poll for interrupts).

With this fix, many more 64K should now work properly. Happy day! This will be folded into build 0.9... soon.

Still can't figure out the Manic Miner jumping issue... but of the two problems, that's a lesser concern.

 

[wavemotion]

https://github.com/wavemotion-dave/DracoDS

V0.9: 11-July-2025 by wavemotion-dave

• Full 64K support working - Sailor Man plays!
• Ability to swap a disk in the mini-menu.
• Improved joystick handling options.
• Improved artifact handling - new options to swap the Blue/Orange artifacts or turn them off.
• Other minor improvements as time permitted.

Looking good... it's pretty clear to me this won't ever be my most popular emulator but I'm proud of it anyway

Just a bit more cleanup and rounding off some rough edges and it will be good to go.

 

[Chillimonster]

Quite right to be proud of it.

It may have been one of the less popular computers but they hold a special place for many people. Myself included.

Thanks again (off to play some more donkey king!)

 

[ber71]

I've just given dracods a try for the first time. Very well polished, as always.
A small qol suggestion. Some game collections use the .rom extension for cartridges, but these do work perfectly when renamed to .ccc. Maybe dracods could list .rom files directly.

 

[wavemotion]

Some game collections use the .rom extension for cartridges, but these do work perfectly when renamed to .ccc. Maybe dracods could list .rom files directly.

I'll make that happen right now and it will be included in the upcoming 1.0 release.

 

[wavemotion]

https://github.com/wavemotion-dave/DracoDS

V1.0: 13-July-2025 by wavemotion-dave

• Fixed keyboard graphic (glitch on key 8 and 9)
• Fixed Semi Graphic 24 mode (fixes Protector, etc)
• Fixed button issues on Buzzard Bait
• Improved handling of Digital Offset (El Bandito)
• Allow .ROM files to be loaded (same as .CCC files)
• Improved Dungeons of Daggorath macros
• More cleanups and a bit of polish for the first big release.

 

[djleviticus]

Wow thanks Dave. I've been off the radar recently. You've got on so well with this emulator. Thanks again for all you do and the time you put into it.

 

[wavemotion]

https://github.com/wavemotion-dave/DracoDS

V1.1: 18-July-2025 by wavemotion-dave

• Fixed DAA instruction - BCD math now correct. Fixes Trapfall, Atom and more.
• Improved Semi-Graphics handling so occasional tops of fonts are not cut-off.
• Improved joypad 'Center+Offset' handling.
• Other minor cleanups as time permitted.

A nice cleanup release. Finally got the bug that was preventing Atom and Trapfall from working. Still can't figure out the Manic Miner jumping issue - but at least you can go play that one on SpeccySE

 

[CrashMidnick]

Thanks, Dave !

 

[djleviticus]

Thanks Dave

 

[wavemotion]

Productive weekend - I managed to find and fix the FDC disk controller inaccuracy and we can now load and run OS9-level 1 games (not many games... but some good ones in the mix!). I also optimized the high-rez artifacting mode and gained almost 50% speed up - to that end, I've completely eliminated the frameskip on the DS-Lite and older DS hardware should now be blazingly fast. I've also made some other improvements as time permitted including a boost of the sound volume (it was a bit too low).

 

[wavemotion]

https://github.com/wavemotion-dave/DracoDS

V1.2: 22-July-2025 by wavemotion-dave

• Improved FDC disk handling - OS9 games now load and run.
• Improved artifacting - less glitches and 50% faster. DS-Lite no longer has any frameskip!
• Added 'Muddied Green' artifacting for the non Black/White color set.
• Added 'Diagonals' as a d-pad option for Q-Bert like games.
• Speedup POKE is now available to boost CPU speed to an effective 1.78MHz
• Fixed Skiing cart so it now runs past the 'Get Ready... Get Set' voice.
• Boosted sound 50% across the board

Another nice solid release with just about everything working. The 50% speedup means I now retire the frameskip for older DS units. This thing should run the same for any DS hardware now.

I think the only game that won't run currently is Manic Miner with the jumping issue. Perplexing that game... but it's a very small loss as you really should play the original on the Speccy anyway

 

[nitrozz]

I try this game
Cave.dsk
Wizard.dsk
Don’t work

 

[wavemotion]

I try this game

Cave.dsk
Wizard.dsk
Don’t work

Not 100% sure what games you're referring to... but if you mean Cave Walker and Wizards Castle (both OS9 games), they work fine. Be sure you're using the OS9 versions at 160K disks... not the Nitros OS9 or other flavors which are not designed for CoCo 2.

Always get them from the CoCo Archive so you know you're getting the proper dumps.

 

[plasturion]

I can't get correct palette for Chuckie Egg, colors seems to be not right.
Ladder should be blue, and cage yellow.
Do I have to setup emulator in some way?

 

[wavemotion]

Holy crap! I had the color palette wrong this whole time for some graphics modes - essentially swapping blues/yellows and reds.

Sigh... it's a good reminder that I'm not as clever as I think sometimes

I'll get this fixed up in the next hour or so... and get a daily build up on github.

 

[wavemotion]

https://github.com/wavemotion-dave/DracoDS

V1.3: 26-July-2025 by wavemotion-dave

• Fixed color palette so reds, greens and blues show properly for the various non-artifacting graphics modes.
• Improved artifact handling so it's a little faster and a bit more accurate.
• IRQ latching improved so more games run more accurately.
• Other minor cleanups as time permitted.

I took a good look at the color palette and decided to make some tweaks to improve the colors. Spent a lot of time on YouTube and with other emulators to see how close I could get the colors to look on the DS handheld. To that end, I think things got pretty close.

 

[plasturion]

Now colors looks very nice and vibrant, even better than homebrew port. I know lcds may differ here but anyway very similar plus slide and glide setting and save states make this game prior of choice. Thanks!

Spoiler

 

[wavemotion]

Just cleaning up my github archive for this... added a new section of the Readme file listing the games that I really enjoyed while undertaking this project.

Recommended Games:​

If you're new to the Tandy Coco / Dragon scene, here are some games that I enjoy. This is not an exhaustive list nor is it an indictment on other games that might be someone else's favs... but these are games that I personally enjoy and run quite well on the DS handheld.

• Dungeons of Daggorath
• Dragon Slayer
• Temple of ROM
• Polaris
• Downland
• Monster Maze
• Canyon Climber
• Fahrfall (homebrew)
• Draco (Draconian clone)
• Donkey King / The King
• Sailor Man (Popeye clone)
• Outhouse
• Space Assault
• Spidercide
• Astro Blast
• Whirlybird Run
• Devil Assault
• Shock Trooper
• Time Bandit
• Dragonfire
• Caves of the Unwashed Heathen
• Dungeon Raid
• Protector II
• Dunjunz
• Turtle Attack
• Wizards Den

 

[nitrozz]

some coco games stop loading with "S" left top screen, whats this means ?