Author Topic: Mega ED Pro  (Read 19650 times)

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Offline Relikk

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Re: Mega ED Pro
« Reply #45 on: June 17, 2020, 12:36 PM »
I think MD+ does not have advantages over mcd mode1, actually mode1 is more powerful and flexible.  Also mode1 can be used with real mega-cd, while MD+ only for premium flashcarts. Seems like at the moment only TO trying to push MD+, if this thing will ever become very popular i will be forced to implement it, but i hope world will stay at "single charger".

Mode 1 is very inefficient, and doesn't support track fading or looping, so you can get rid of unnecessary audio and prevent bloating audio pack releases with optimised loops.

Mode 1 inefficiency means that patches have to include a sub-CPU program, decompress the BIOS (so you have to include that decompression routine in the ROM), copy the sub-CPU program, bootstrap the sub-CPU, and then communicate with it through the ASIC ports. MD+ has all that logic in the cart MCU, so you just need to write commands to a special address and the cart MCU will handle them as if you had set a sub-CPU program.

Just compare the patches. MD+ patches are a couple of hundred bytes. Mode 1 patches are hundreds of kilobytes.

Offline KRIKzz

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Re: Mega ED Pro
« Reply #46 on: June 17, 2020, 12:50 PM »
I think MD+ does not have advantages over mcd mode1, actually mode1 is more powerful and flexible.  Also mode1 can be used with real mega-cd, while MD+ only for premium flashcarts. Seems like at the moment only TO trying to push MD+, if this thing will ever become very popular i will be forced to implement it, but i hope world will stay at "single charger".

Mode 1 is very inefficient, and doesn't support track fading or looping, so you can get rid of unnecessary audio and prevent bloating audio pack releases with optimised loops.

Mode 1 inefficiency means that patches have to include a sub-CPU program, decompress the BIOS (so you have to include that decompression routine in the ROM), copy the sub-CPU program, bootstrap the sub-CPU, and then communicate with it through the ASIC ports. MD+ has all that logic in the cart MCU, so you just need to write commands to a special address and the cart MCU will handle them as if you had set a sub-CPU program.

Just compare the patches. MD+ patches are a couple of hundred bytes. Mode 1 patches are hundreds of kilobytes.

Everything listed like tracks fading and looping supported by mode1, it only matter of mcd driver. Even interfacing can be as simple as MD+. Also you don't even need to use CD bios, few kilobyte sub cpu driver can do all work.

Offline nuu

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Re: Mega ED Pro
« Reply #47 on: June 17, 2020, 03:32 PM »
Although I don't know the details, I also think a MSU-1 variant for the MD is a strange invention when it already has CD hardware. If it really reduces the size of the patches and has more features it might be defensible though.


So I'm gonna assume this  probably isn't an issue for Terraonion, and Pro as far as things go. According to them they were very careful to keep the voltages within the margins of safety. It draws less then the Virtua Racing cart.
No it's not just about power draw, it's about translation of logic levels (voltage) between parts. The SD card for example is a 3.3V part and is not tolerant to 5V which the MD is using, and the FPGA might also work on 3.3V only. So it's necessary to convert the communication between the 3.3V and 5V parts so that each part works with its expected logic level. Many pirate and bootleg carts from China (but not any official Everdrives) are skipping this part entirely and doesn't even have resistors to limit the the current, which means they are potentially dangerous to the hardware (although this varies a bit between different types of hardware). I have no idea if Terraonion's stuff are correctly built or not though.
Soon someone might post a reassuring video from BennVenn (who is in the Flashcart business for the Game Boy) where he "proves" that all pirate carts are totally safe, but I'm quite sure that that statement simply is not the truth. This is a hot and infected topic with lots of business interests and probably personal feelings involved.

Offline Neto

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Re: Mega ED Pro
« Reply #48 on: June 18, 2020, 10:50 PM »
I can force SSF mapper for your game, but carts with one time programmable fpga like x5 and x3 still not be able to support sram in way how you using it.
"I can force SSF mapper for your game, ...". Thanks, this will make the game compatible with some emulators, which crashes if SSF header is found when I try to access SRAM .

"May be you could include simple check to detect what type of mapper used and then use supported banck switching model?"
Done ( https://www.neto-games.com.br/rom_hack/Sonic_Delta_v042.rar ) . Now the Game can Detect Everdrive and call appropriate routine. Tested on X3 and SRAM worked.




Offline Turbine Graphics 16

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Re: Mega ED Pro
« Reply #49 on: June 19, 2020, 04:01 PM »
I think a good idea for Mega ED pro would be to have the possibility of nes games enhanced with the extra background of the megadrive so you could for example hack the megaman games to have an extra background almost like wily wars.

Offline Marteicos

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Re: Mega ED Pro
« Reply #50 on: June 20, 2020, 03:36 AM »
I can force SSF mapper for your game, but carts with one time programmable fpga like x5 and x3 still not be able to support sram in way how you using it.
"I can force SSF mapper for your game, ...". Thanks, this will make the game compatible with some emulators, which crashes if SSF header is found when I try to access SRAM .

"May be you could include simple check to detect what type of mapper used and then use supported banck switching model?"
Done ( https://www.neto-games.com.br/rom_hack/Sonic_Delta_v042.rar ) . Now the Game can Detect Everdrive and call appropriate routine. Tested on X3 and SRAM worked.
On my X5 it keeps saying, unsupported rom, like v039 and v040. My PCB is Rev B.

Offline nuu

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Re: Mega ED Pro
« Reply #51 on: June 20, 2020, 05:59 PM »
I think a good idea for Mega ED pro would be to have the possibility of nes games enhanced with the extra background of the megadrive so you could for example hack the megaman games to have an extra background almost like wily wars.
The NES doesn't use the Mega Drive hardware, it's basically all in the FPGA. You can add any number of backgrounds to it if you want, but it would no longer be a NES by definition. It would be a new system.

Offline TheShadowRunner

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Re: Mega ED Pro
« Reply #52 on: June 20, 2020, 06:50 PM »
Hmm I'd much rather have had MD+ support than a NES simulator frankly....

Offline NerdyBros

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Re: Mega ED Pro
« Reply #53 on: June 21, 2020, 02:15 AM »
This is looking really good! How soon can we get our nerdy little hands on it?

Offline updawg

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Re: Mega ED Pro
« Reply #54 on: June 21, 2020, 09:49 PM »
Will the sega cd functionality work when connected through a 32x or will we have to take off the 32x? Thanks!

Offline Lord Awesomesauce

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Re: Mega ED Pro
« Reply #55 on: June 21, 2020, 10:29 PM »
Will the sega cd functionality work when connected through a 32x or will we have to take off the 32x? Thanks!

You'll have to remove the 32X, it's not possible to get SMS or CD working through the 32X as it doesn't support what's needed.

Offline updawg

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Re: Mega ED Pro
« Reply #56 on: June 22, 2020, 03:10 AM »
Will the sega cd functionality work when connected through a 32x or will we have to take off the 32x? Thanks!

You'll have to remove the 32X, it's not possible to get SMS or CD working through the 32X as it doesn't support what's needed.

Are there any mods to passthrough all the needed pins? I see a mod to make a powerbase converter work on a 32x  -wondering if anyone has plans to try and make all of this work at once.

Offline Lord Awesomesauce

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Re: Mega ED Pro
« Reply #57 on: June 22, 2020, 03:05 PM »
Nope, no mods. Any mod like that to get CD working through a 32X would be incredibly complex and complicated to do, assuming it's even possible at all.

I personally don't see such a mod ever happening.
« Last Edit: June 23, 2020, 12:43 PM by Lord Awesomesauce »

Offline Galron

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Re: Mega ED Pro
« Reply #58 on: June 23, 2020, 02:54 AM »
TerraOnion are saying that SMS menu, and save states are something that will be added in a future firmware update.

Offline Galron

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Re: Mega ED Pro
« Reply #59 on: June 25, 2020, 03:50 AM »
Although I don't know the details, I also think a MSU-1 variant for the MD is a strange invention when it already has CD hardware. If it really reduces the size of the patches and has more features it might be defensible though.


So I'm gonna assume this  probably isn't an issue for Terraonion, and Pro as far as things go. According to them they were very careful to keep the voltages within the margins of safety. It draws less then the Virtua Racing cart.
No it's not just about power draw, it's about translation of logic levels (voltage) between parts. The SD card for example is a 3.3V part and is not tolerant to 5V which the MD is using, and the FPGA might also work on 3.3V only. So it's necessary to convert the communication between the 3.3V and 5V parts so that each part works with its expected logic level. Many pirate and bootleg carts from China (but not any official Everdrives) are skipping this part entirely and doesn't even have resistors to limit the the current, which means they are potentially dangerous to the hardware (although this varies a bit between different types of hardware). I have no idea if Terraonion's stuff are correctly built or not though.
Soon someone might post a reassuring video from BennVenn (who is in the Flashcart business for the Game Boy) where he "proves" that all pirate carts are totally safe, but I'm quite sure that that statement simply is not the truth. This is a hot and infected topic with lots of business interests and probably personal feelings involved.

TerraOnion, says none of that was ever an issue with their cart, they made sure the power draw conversion was right from the get go.