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Titan releases Mega Drive tech docs

category: code [glöplog]
This is our first item in a series of follow-ups about the making of Overdrive 2: everything we figured out about the Mega Drive hardware.

I hope this will clear many things up and inspire more people to play with this platform!

https://docs.google.com/document/d/1ST9GbFfPnIjLT5loytFCm3pB0kWQ1Oe34DCBBV8saY8/pub
added on the 2017-04-19 20:17:55 by Kabuto Kabuto
<3
added on the 2017-04-19 20:21:23 by ferris ferris
Neat! Most of this is well beyond my understanding but big props for putting it out there. It'll be amazing to watch what new developments come out of it. :)
added on the 2017-04-19 20:36:24 by jmph jmph
Lovely!
added on the 2017-04-19 20:37:47 by leGend leGend
amazing effort!

but a small suggestion: how about you also do a nice PDF of it and upload it to scene.org? then the preservation will be potentially more long-lasting: one never knows how long particular google services are going to last, and people will surely want to read these docs also in 10 or 20 years time, just as we can now read 20 year old coder docs on scene.org!
added on the 2017-04-19 21:08:01 by dipswitch dipswitch
Good work!
added on the 2017-04-19 22:04:32 by ham ham
right on
added on the 2017-04-19 22:43:10 by sigflup sigflup
Amazing! Great to see people really delve into a platform like this. I think there are lots of neat stuff to be discovered on some of the lesser used (at least from a demoscene perspective) hardwares of the 80ies/90ies.
added on the 2017-04-19 23:22:11 by Sdw Sdw
Excellent! This kind of documents was what diskmags were released for...
added on the 2017-04-20 06:53:35 by Adok Adok
I really doubt any emulator developer will care. How would they even implement a register that behaves differently on different consoles?
added on the 2017-04-20 17:33:33 by the_Ye-Ti the_Ye-Ti
There are things called "settings". Various emulators already emulate revision-specific behaviours of various platforms.

Nice write-up!
Quote:
I really doubt any emulator developer will care. How would they even implement a register that behaves differently on different consoles?


according to the traffic we got in our #titandemo IRC channel they do care indeed =)
added on the 2017-04-20 17:57:49 by wysiwtf wysiwtf
Nice!! But waiting for the next parts.. where you explain HOW THE FUCK YOU DID THAT STUFF!! :D
added on the 2017-04-20 22:13:55 by DanLemon DanLemon
Quote:
This is our first item in a series of follow-ups about the making of Overdrive 2: everything we figured out about the Mega Drive hardware.


I thoroughly approve. Thank you so much for doing this!

Quote:
I really doubt any emulator developer will care.


Well, never say never. When we wrote 8088 MPH and published all the info about what we did, there were a few people who got a few emulator forks a little bit better. Not 100% percent, but there was some positive movement.
added on the 2017-04-21 04:50:51 by trixter trixter
Indeed, there are some emulator projects that care strongly about accuracy, like MAME, Exodus (stagnated?), and Higan (formerly BSNES, Megadrive support is in progress).
added on the 2017-04-21 12:16:08 by absence absence
MAME/MESS is the worst emulator of those. Almost four years later, it still does not emulate OD1 properly.

Exodus seems stagnated (guy is busy) and byuu (Higan author) is throwing a fit over the fact that the first VDP chip is broken and MDs with that have graphical glitches with our demo and is refusing to emulate that.

Mask of Destiny is working on BlastEm and has made really promising progress!

And Eke (Genesis Plus GX) always has something up his sleeve - I'm sure of that ;)
added on the 2017-04-21 12:33:09 by oerg866 oerg866
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Quote:
One more effect/scene that's majorly broken and then it's on to the interaction between debug register and the border area + a couple of minor issues
added on the 2017-04-21 12:36:54 by oerg866 oerg866
I salute you, and feel that more people should document their work.

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added on the 2017-04-21 14:36:55 by sol_hsa sol_hsa
wysiwtf:: ah being in direct contact with them dvelopers helps ofcourse :)
Quote:
MAME/MESS is the worst emulator of those.
that one was quite fast in emulating that 16MB piersolar bankswitcher, right?
added on the 2017-04-22 09:24:36 by the_Ye-Ti the_Ye-Ti
It was only 8MB, and much less a bankswitcher than an encryption mechanism :P
added on the 2017-04-22 15:17:35 by oerg866 oerg866
Quote:
I really doubt any emulator developer will care. How would they even implement a register that behaves differently on different consoles?


Lol.
https://twitter.com/mikepavone/status/855336741430902785
added on the 2017-04-22 17:08:09 by fra fra
Hey Kabuto, any way to contact you ? I'd like to fix MiSTer to support the vertical border effect. Thx !
❤️
added on the 2019-01-21 12:14:53 by maeln maeln

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