[WIP] Tetris conversion

[Toni Galvez]

I always loved the arcade version of Tetris, good work!! Specially the music is one of the nicest soundtracks on any Tetris version.

[jotd]

Yes Brad Fuller (one of Atari lead musicians with Hal Canon) is not russian but he is a true music artist. The tunes are great!

[kamelito]

Converting CPU stuff is one thing but how do you decipher hardware banging stuff like sound/gfx/input…?

[jotd]

Originally Posted by kamelito

Converting CPU stuff is one thing but how do you decipher hardware banging stuff like sound/gfx/input…?

for sound, I usually find the "sound play" routine and replace it by machine dependent sample play.


Same for music. Here I'm going to emulate pokey instead to avoid recreating the tunes, it has little interest.



for graphics, I change the memory write to the video memory by specific calls (for background tiles). And sprites are scanned from the original sprite memory and converted to amiga sprites/bobs (no sprites here, much easier).


Inputs go the same way: figure out which bits the game tests and feed it machine dependent inputs.




Credits to Mark (tcdev) for designing this way of doing things and showing me how to do in Xevious

[kamelito]

Yeah but I suppose that those Arcade games do have HW features so you need to know how to display a sprite, a tile, etc on those specific hardware right? Something like a HRM for those boards.

[jotd]

HRM = just MAME source code. Not very easy but after a while you manage.

Ripping the graphics with proper palette is quite the challenge. That time I directly checked which binary file was used for tiles in MAME source code, and figured the format out , also by running MAME on the game and pressing F4 to get tile indexes.

I used MAME gfx save too for Bagman. Not here I can't because the palette is dynamic, but reading the tile file was straightforward. No fancy tricks. Luck is a big part of the process!

MAME is an invaluable tool to successfully do those 1:1 ports. That's why such ports were theorically possible since 1985 but actually aren't because we had no way to get proper graphics and debug for those original boards.

[JoeJoe]

It is also important which addresses are for what. And how does the arcade hardware view work? So graphics memory, which pokes are used to display sprites. How many sprites are there and the color space for graphics and sprites.
For my port it was exciting to find out how the whole thing works. And yes, a lot of time was spent on reverse engineering.
But without MAME it wouldn't have been possible for me.

[saimon69]

Originally Posted by jotd

HRM = just MAME source code. Not very easy but after a while you manage.

Ripping the graphics with proper palette is quite the challenge.

For the most basic and repeating elements there is the screenshot option too - for a game like tetris should work fine most of the times,

[jotd]

there are 2048 tiles and 16 different 16 color palettes, which can be adjusted dynamically. So taking screenshots doesn't work very well

[saimon69]

However if i remember the game, most elements do not change too much from level to level, like tetronimes and borders

[note] you want an ACCURATE conversion, i am more in A conversion so have different goals though

[jotd]

new video, game is playable: [ Show youtube player ]

Sound is cruelly missing though!

[desiv]

Originally Posted by jotd

new video, game is playable: [ Show youtube player ]

Sound is cruelly missing though!

Looks great!!!

I'm not too worried about the missing sound...
I can't even see a moving box without the Tetris theme starting to play in my head... ;-)

[TCD]

Originally Posted by jotd

new video, game is playable: [ Show youtube player ]

Sound is cruelly missing though!

No pressure, but maybe we get a Christmas present?

[jotd]

a preview version will be available in a few days I think. Full video but no sound yet.

[franeti]

Originally Posted by jotd

a preview version will be available in a few days I think. Full video but no sound yet.

Watching the video my mind put the music hahaha

Awesome work, a lot of thanks for this port!!!

[jotd]

demo version in the zone. No sound, otherwise pretty complete & playable

[h0ffman]

Love me a bit of Tetris so looking forward to this. My fave version is Tetris Effect played in VR, if you love Tetris then I'd highly recommend it.

[ransom1122]

Nice, [ Show youtube player ]

I know its super early though what i saw

1. Winuae - Full Screen, starting Medium game crashes
2. Crashed after Round 2 playing in Full Screen Window
3. Random other crashes on either window or fullscreen

Keep up the good work jotd

[redblade]

What's the code size compared to the 6502? I know that the 68k has more registers available but the instruction size jump to 16bits, and then a possible 32bits for memory location is a big step up from the 8bit.

Is 68k 4 times bigger? (excluding sound code)

[TCD]

Nice! Just had a quick go and it seems to work fine (on WinUAE)