Using MAME/MESS NES SL ROMs with other Emulators?

[konkeydong1991]

So I'm a bit anal retentive about having to collect multiple ROM sets for the same platform.

I maintain a full MAME/MESS SL set, and I believe the NES ROMs are the only ones that refuse to work with other emulators.

They're all headerless/seperate CHR/PRG files inside of zip files, rather than a compiled .NES file with a header.

Is there any sort of command-line script I can run to compile an NES file, on the fly, when I attempt to run these games?

Otherwise I have to maintain a no-intro ROMset, as well, just for the NES games.

We're talking <100MB, not the end of the world, but my MAME/MESS collection is the jewel of my emulation hoard, and I'd really prefer to use it to it's full potential.

Edited August 3, 2021 by konkeydong1991

[konkeydong1991]

Looks like others have been down the same rabbit hole with no success: 

I guess I'll just keep using my no-intro set, for now.

[sundogak]

I went down this road as well at one point. I wasn't worried about the storage but just preferred to pull from one master set. 

You can convert the MAME zip files into a iNES/NES 2.0 (*.NES) format using UCon64.  The problem is the "on the fly" portion. To convert, you have to provide some key data such as mirroring and mapper type to UCon64 so it properly sets up the header that most non-MAME emulators expect to see. That data could be put in a batch file after unzipping the MAME file but to my knowledge there is no easy way to auto lookup the data needed without doing some code.  The MAME NES HASH file actually contains much of the per game information you need for UCon64 to convert to NES. If using MAME as NES emulator it looks inside the zip, goes to the Hash file and compares the checksums and uses the data within the Hash to figure out how to properly run the game with the PRG, CHR, etc, components.  Basically, the HASH replicates the header data for NES format.  For MAME it makes sense they do it that way since fits there overall model of how dump ROMs, but does make sharing MAME ROM sets with non-MAME emulators problematic (or vice versa really). 

But with all that, like you said, if you have a full No-Intro set it wouldn't be worth all the gyrations to get from the MAME set to the NES format in that you would need to work custom batch files per cartridge to call Ucon64.  I have done a few one-offs from MAME set to use for non-MAME NES emulator but it would be crazy time consuming unless you were a coder.  

Edited August 3, 2021 by sundogak