Draco-DS - A Dragon / Tandy CoCo Emulator

[wavemotion]

I have literally nothing started on this so no promises... (okay, not quite true as I've started looking at some open-source projects for these machines)

but it's the last of the 8-bit machines that has the 256x192 resolution of the DS/DSi/XL/LL.

The name is an amalgamation of Dragon and CoCo and was coined by @Indy13 and is quite brilliant.

 

[Flame]

Is it a bird. Is it a plane. No its @wavemotion

 

[AmandaRose]

Will it just be Dragon 32/64 compatible or will it also run the enhanced Dragon 200E??

Either way pretty cool to see this relatively unknown to most (not me) little Welsh micro getting some love.

 

[wavemotion]

Will it just be Dragon 32/64 compatible or will it also run the enhanced Dragon 200E??

If memory serves, the 200E included the 80 column card and enhanced VDP... so probably would be out of scope. At least initially it would be a Dragon 32/64 and Tandy CoCo 2 emulator.

Then again, it doesn't really exist. Yet.

 

[AmandaRose]

If memory serves, the 200E included the 80 column card and enhanced VDP... so probably would be out of scope. At least initially it would be a Dragon 32/64 and Tandy CoCo 2 emulator.

Then again, it doesn't really exist. Yet.

Yep you are right about the 200E including the 80 column card and enhanced VDP.

but it's the last of the 8-bit machines that has the 256x192 resolution of the DS/DSi/XL/LL.

You are forgetting about the awesome SAM Coupé (Aka The Super Spectrum) It's 8bit and it's screen resolution is 256x192 in mode 1 and mode 2 and mode 4. Only problem would be for games/software that uses mode 3 that runs at 512x192.

Basically I would love a Sam Coupé emu for DS

 

[djleviticus]

Wow this could be very interesting

 

[Chillimonster]

but it's the last of the 8-bit machines that has the 256x192 resolution of the DS/DSi/XL/LL.

I always thought the Oric 1 had the same resolution but it didn't - not far off at 240×200 though

Anyways, looking forward to seeing where this one goes, absolutely loving the recent additions (c64 / ZXS / CPC)

 

[wavemotion]

I always thought the Oric 1 had the same resolution but it didn't - not far off at 240×200 though

Anyways, looking forward to seeing where this one goes, absolutely loving the recent additions (c64 / ZXS / CPC)

That's reasonable for the DS. Provided the Oric 1 (which I know nothing about) doesn't have funky ways to stretch/manipulate the resolution.

I was duped by my friend @CrashMidnick with the Amstrad which looks to have a 160x200 and 320x200 as the most common resolutions but really those modes can be extended to 192x272 and 384x272 with CRTC tricks. And, of course, most homebrews use the tricks

 

[CrashMidnick]

You are forgetting about the awesome SAM Coupé (Aka The Super Spectrum) It's 8bit and it's screen resolution is 256x192 in mode 1 and mode 2 and mode 4. Only problem would be for games/software that uses mode 3 that runs at 512x192.

Basically I would love a Sam Coupé emu for DS

It is funny @wavemotion, we talked about this little beast about 2 weeks ago It is a sign !

 

[wavemotion]

Doing a bit more skunkworks tinkering with breakfast this morning. I did manage to get the Dragon32 (rPI) CPU to compile under my existing toolchain. Still not much to write home about.

 

[Indy13]

Ho! That's so cool, first of all thanks for the wink my friend! I can't wait to see the first results, for sure one of the first games I'll try will be Dragonfire, this game is excellent!


@wavemotion The artwork is so cute, I love it!

 

[wavemotion]

Just more tinkering with coffee this morning... still nothing meaningful done.

And yes, that's how you spell Color my overseas friends

 

[wavemotion]

Some small progress...

Took SpeccySE and gutted out all of the Z80 CPU and AY sound code plus the Video Driver and added in some basic loading screens.

It does absolutely nothing, of course... there is no CPU nor video driver so it's just a paper-weight. But it's looking nice

Next up is to get the basic memory map and CPU core running.

 

[CrashMidnick]

You're on fire, Dave. Thanks !

 

[wavemotion]

ShaBOOM!

What you can't see in the pic is a flashing cursor.

No keyboard input is hooked in... and the CPU is running at very much the wrong speed... But now nothing can stop it from happening.

I had forgotten how much I love when the pixels are 1:1 on the DS!

 

[Chillimonster]

No repo to 'star' yet?

 

[Indy13]

And then there was light !

 

[Chillimonster]

What file type are you looking at supporting on this one (just so I can start prepping my files )

 

[wavemotion]

What file type are you looking at supporting on this one (just so I can start prepping my files )

At this time, I'm supporting carts (for Tandy, these are .CCC files -- less sure if Dragon carts were a thing) and the more important .CAS cassette files.

A lot of stuff is now working. Sound is in - passable at best but the Tandy wasn't great at sounds. Mostly farting noises and such.

Artifacting is in and it looks great - surprised, really, at how close it is to real HW.

But there are some major obstacles I've encountered... Dungeons of Daggorath crashes right after loading and I have no idea why. And that's my favorite Tandy CoCo game!

Dragonfire hits the color registers on mid-scanline boundaries and that's a problem for my poor little emulator... it means the colors won't look right without a major redesign. The game will otherwise play fine.

So it's a mixed bag so far... still working on it.

 

[Chillimonster]

Superb progress!

Looking forward to playing Donkey King (The King) from microdeal when this gets released.

It’s been a few years!