4 ms·

could somebody tell me why all the ROMs need updating _every time_ a new version of MAME is released? it would seem like a major cockup: updating the data, the

by cpill 3y ago

could somebody tell me why all the ROMs need updating _every time_ a new version of MAME is released? it would seem like a major cockup: updating the data, the ROM dumps which I imagine are always the same as they come from hardware(?), instead of the code? imagine if everyone had to update the data in their databases every time a new minor version of the database software was released!

chungy 3y ago
Short answer: They don't all need updating. Many of the most popular games go on for years without needing any updates, and usually if you already have settled on specific games and revisions thereof, you won't need to update. Longer answer: Every MAME update changes things, which includes adding, removing, and changing the definition of ROMs. Due especially to the nature of arcade games, there aren't convenient de facto wrapper formats (like, say, .nes or .sfc files), and MAME just defines each independent ROM as their own files, with MAME's own idea of what the names should be and accompanying sha1 hashes. If MAME developers/contributors have discovered that a game revision previously dumped was incorrect (as is the case in TFA), it might be replaced with a known good dump. In that case, you are expected to redump the game from your arcade board, this time the right way (or well, pirate the game, which most MAME users do...). It may seem annoying, but it's the nature of game preservation. It'll never be in a perfected and finished state.
- lupire 3y ago
  It would be nice for MAME the "multiple arcade machine emulator" to be MAMAME the "multiple arcade machine and MAME emulator" , so that it could play ROMs built for older versions of MAME. PlayStation can emulate its older versions.
  - chungy 3y ago
    You could run old versions of MAME. To be fair, no ROMs are "built for MAME", just that MAME's database changes.
ksherlock 3y ago
Based on dates in the merged ROM set I checked, there were 170 new/updated ROMs in MAME 0.263 (Feb 2024) and 90 for MAME 0.262 (Jan 2024). Those were from merged rom sets so every zip file has 1-20 individual ROMs inside The denominator here is 14,566 so that's 0.6% to 1.1% per month which is substantially less than all. These would mostly be ROMs for machines that weren't previously supported, replacing high level emulation with low level emulation, new ROM dumps, and replacing bad dumps.
ZFH 3y ago
I agree it's not optimal. It's not like every game changes on every MAME release, but some indeed get re-dumped from time to time. The usual example is encrypted audio data or color palette ROMs. In an earlier version, lacking the ability to decrypt them they would be emulated with samples or code respectively, then once it's possible to dump them they get integrated into the romset for better accuracy.
nubinetwork 3y ago
I agree that that's annoying as well... but coincidentally something similar can also happen to NES/SNES emulators if they use a "ROM database". They aren't quite versioned like on mame, but if you don't use their special checksummed ROMs they will run, but try telling you that you have a bad dump... only problem is that most NES ROMs have bad headers altogether. (I've seen a lot that say they have 8k of battery-backed SRAM when they infact don't. I wound up spending a week rewriting the headers on my ROMs from scratch, referencing the pcb pictures online. Edit: this also includes bad Disk Dude overdumps that still haven't been fixed ~40 years later...)

by cpill 3y ago

chungy 3y ago

Short answer: They don't all need updating. Many of the most popular games go on for years without needing any updates, and usually if you already have settled on specific games and revisions thereof, you won't need to update. Longer answer: Every MAME update changes things, which includes adding, removing, and changing the definition of ROMs. Due especially to the nature of arcade games, there aren't convenient de facto wrapper formats (like, say, .nes or .sfc files), and MAME just defines each independent ROM as their own files, with MAME's own idea of what the names should be and accompanying sha1 hashes. If MAME developers/contributors have discovered that a game revision previously dumped was incorrect (as is the case in TFA), it might be replaced with a known good dump. In that case, you are expected to redump the game from your arcade board, this time the right way (or well, pirate the game, which most MAME users do...). It may seem annoying, but it's the nature of game preservation. It'll never be in a perfected and finished state.

lupire 3y ago
It would be nice for MAME the "multiple arcade machine emulator" to be MAMAME the "multiple arcade machine and MAME emulator" , so that it could play ROMs built for older versions of MAME. PlayStation can emulate its older versions.
- chungy 3y ago
  You could run old versions of MAME. To be fair, no ROMs are "built for MAME", just that MAME's database changes.

ksherlock 3y ago

Based on dates in the merged ROM set I checked, there were 170 new/updated ROMs in MAME 0.263 (Feb 2024) and 90 for MAME 0.262 (Jan 2024). Those were from merged rom sets so every zip file has 1-20 individual ROMs inside The denominator here is 14,566 so that's 0.6% to 1.1% per month which is substantially less than all. These would mostly be ROMs for machines that weren't previously supported, replacing high level emulation with low level emulation, new ROM dumps, and replacing bad dumps.

ZFH 3y ago

I agree it's not optimal. It's not like every game changes on every MAME release, but some indeed get re-dumped from time to time. The usual example is encrypted audio data or color palette ROMs. In an earlier version, lacking the ability to decrypt them they would be emulated with samples or code respectively, then once it's possible to dump them they get integrated into the romset for better accuracy.

nubinetwork 3y ago

I agree that that's annoying as well... but coincidentally something similar can also happen to NES/SNES emulators if they use a "ROM database". They aren't quite versioned like on mame, but if you don't use their special checksummed ROMs they will run, but try telling you that you have a bad dump... only problem is that most NES ROMs have bad headers altogether. (I've seen a lot that say they have 8k of battery-backed SRAM when they infact don't. I wound up spending a week rewriting the headers on my ROMs from scratch, referencing the pcb pictures online. Edit: this also includes bad Disk Dude overdumps that still haven't been fixed ~40 years later...)