MAME versions suffixed by "u" - sub updates?

[vbs_]

I have learned that there is a new ROM set for every new MAME version. The current version is 0.179. Someone told me I need version 0.139 for my emulator. So I downloaded the DAT file for 0.139 from here:
http://www.progettosnaps.net/dats/

But in the archive for 0.139 there is not just one DAT file, there are:
MAME 139.dat
MAME 139u1.dat
MAME 139u2.dat
MAME 139u3.dat
MAME 139u4.dat

So please, what does "u1" (and so on) mean? Are those further updates within 0.139? Why aren't they just 0.140 (and 0.141 etc.) then?
And when someone speaks about 0.139, which version does he mean? The real "MAME 139.dat" or is the latest version meant ("MAME 139u4.dat")?

Lots of question, thanks guys!

[Zorlon]

best way to use clrmamepro is via the mame exe (official release) not through dat files

you can find older releases at http://www.mame.net/oldrel.html

you just use clrmamepro using the dat from exe option

[vbs_]

Thanks, but but... I am not on Windows, I am using Retropie (https://retropie.org.uk/) on Linux x86 Intel NUC. They ship different forks of MAME:
https://github.com/retropie/retropie-setup/wiki/MAME

I just assume I cannot load those forked Linux executables into clrmamepro so probably I am stuck with those DAT files. In general I would like to understand what this "u4" and so on means on those DAT files.

[Zorlon]

I would presume a minor update (the u4 dat has more roms in it than the previous ones, you can tell by the file size alone)

we are talking about something mame does not do anymore so can't remember off the top of my head to be exact but do remember mame having minor updates after going from one version to the next without increasing the main update version number

[vbs_]

Yeah I compared them also. At first I thought they just added some metadata (like release years) but then I saw they even added new games in those updates. Still a bit strange...
Big thanks though, I will just play around with those emus, the DATs and clrmamepro

[EyMann_MachHin]

Yes, those are minor updates, the MAME team released. But you usually won't find the executables for download and had to compile them yourself. They introduced some new systems removed others, replaced 'good' and removed 'bad' dumps like between the FULL releases. But usually not in the extend as it happens between those full releases. They did stop that practice some time ago. You could call them "unstable" or "developers" releases, since you have to do the compiling yourself.
I always wondered why David Valdeita picked those intermediate ones 37b5 for the original MAME4droid (see, there it was called 'b' for beta ) or for MAME4droid Reloaded 0.139u1 (orginally 0.134u4) also used for iMAME4all. It makes finding the right ROMs or rebuilding them from arbitrary downloads quite hard ... unless you trust some torrent to be what you looking for, but even then I still like to verify the contents. But I'm paranoid and nitpicky regarding this.
I'm in MAME since about 0.27 ... with some years break in between and nowadays I do update my collection like once or twice a year... so even I don't have a full Rollback set to get those intermediate versions back if I need them. But I agree with Zorlon, the best way would be the exact binary, until then those dat files from Progetto are your best choice to verify those sets. Otherwise, I think there are some torrents out there with exactly what you are looking for. Those are cleaned up sets, with games using CHDs (not working on Android) and non working games removed. And I guess that is what you are looking for.

[vbs_]

Thanks mate, very valuable information! I did as you guys proposed and downloaded the MAME EXEs I want and extracted the lists on Windows. Also Retropie is providing DAT files for their specific MAME versions they are shipping:
https://github.com/retropie/retropie.../Managing-ROMs

I hope I will be able to rebuild those using the current set and the rollback set.

[EyMann_MachHin]

I actually overlooked the part, where you mentioned being on RasPi Thanks for the link to the different versions, that definitely clears it up a bit and makes it more difficult since it covers even more versions. And, yes, Lr-MAME2010 is 0.139 baseline no 'u'. .139u1 supports 8847 romsets
Actually you will need the current baseline set you have and all the rollback files from 0.139 until then. Since the .139 rollback only covers the roms that have been removed in that version. And you have to be careful with the CHD files, since they did change the fileformat several times. Not sure which format version was used in 2010 but I gues it was v3. It will make you want to pull your hair out, since you will have to have the version of the CHD supported by your version.
Google might be your friend: "MAME 2010 Reference Set"