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[jclampy]

Hi Roman,

Do you know off the top of your head around what Mame/.Dat Version we would toggle from "Support Inverted CRC32" enabled to disabled?

Just a vague idea or perhaps some 'keywords' I should go and search for in the MAME previous release changelogs would be of help.

Thanks.

[Roman]

You can look for rom status attribute values "baddump" (not "nodump"). If they appear, the dat does not use the inverted crc32 method anymore

But of course you can simply keep the option enabled...it does not really harm.

[jclampy]

Hey thanks, that's great. Was worried I was going to trip up somewhere sooner or later.

I'm using the 'force nodump' header in the .dats at the moment because I like to be able to match what I see in a Mame Audit to a Clrmamepro Audit. Do you know if the "Support Inverted CRC32" might have an impact there when I get up to the Mame .dat versions that don't require it?

[Roman]

The enabled option should not have a sideeffect for MAME.
There might be other dats (without baddump attributes) which accidently have inverted crcs somewhere...but not for the purpose of flagging the file as bad...purely accidently...then the rebuilder might create a wrong file in a wrong set.....but the chance is pretty small...

[jclampy]

While looking something else up I came across the Mame version number for change to 'baddump' flagging;

--------------------------------------------------------------------------------
Since MAME v0.68, a new method of specifying these ROMs has been used; MAME now uses a ROM flag of 'baddump' to indicate that the ROM is incorrect/incomplete/bad. Data files for ClrMamePro should now use the 'flag baddump' syntax in addition to the actual CRC but RomCenter and many other emulators still need to use complemented CRCs.
--------------------------------------------------------------------------------

[Roman]

which brings me to my fav topic...Why the hell do people use old MAME versions at all.....

[jclampy]

As I tried to hint at previously where I have mentioned Mame versions that were used as a base for various ports of Mame to portable devices. I never got around to trying emulators on some old portable devices I have and thought I might like to try them for fun.

On the PC side maybe there is no point going so 'vintage' (although I have a PIII 600MHZ I would like to try with as well) but I can see people using certain older versions of Mame due to 'regressions' that have killed performance in certain game drivers. I know of one driver regressions 'of-the-top-of-my-head' where using a Mame build from beginning of 2009 (and not any build from then to now) is the only option for best experience.

To throw a curve ball, this PC build looks interesting, although I have not tried it yet; DDEmeMame 0.37b16.99.9(2011.02.13)
Based on 0.37b16 but with some modern drivers and bells & whistles added.

All comes down to the individuals wants and needs.

My computer is getting older. Mame is getting more bloated and slower.
But that is not as simple as it sounds. If you think back when Mame could run on a PIII and tried that version on a four or five year old computer today, what would have been the CPU usage? Maybe 10% whereas, modern Mame versions probably run towards 100% CPU usage. So going back to Mame versions a couple of years ago might put you around 50% CPU usage. Having lower CPU usage means you could fire up a game when ever you feel like no matter if you have tasks running in the background, etc..

I won't be updating my PC in the foreseable future either. It can do whatever I need it to do, so not necessary to upgrade.

Anyway, not 'hating' on the modern Mame versions. I just stopped 'following' them is all. I'll still probably look at one on the odd random occasion, I'll most probably be busy elsewhere.

[jclampy]

In regards to using Mame on *PC's* perhaps I will retract and hold back on my judgement for now.
Just tried a Mame version from three years ago and noticed some of the minor graphical glitches in games. So yeah, it is best to check if more modern Mame version's have improvement to driver's you are interested in.
Also the 'slowness by bloatiness factor' with modern Mame versions may have been from using MameUI/32 or other frontends. Just tried Mame 0.148 command line binary and it seemed to not be effected. Although "the 'regressions' that have killed performance in certain game drivers" still exists unfortunately.
It will probably take me a while to find that 'sweet spot'. I think I'll start researching the individual driver improvements.

Addition1:
~~~~~~~
I have run some tests with the 'currently new' Mame 0.148 and found that it can run quite well with the MamepGUI frontend. The MamepGUI frontend has recently been through some version updates and it now works very well with the modern Mame builds. Using the 'currently new' versions of MamepGUI does get rid of the slowness/bloatyness factor of other 'MameUI style' builds.

Mame 0.148 does have performance problems with certain game 'drivers' which you may have to use an older build for, or an alternative emulator if possible. I have not tested alot yet, but I know CPS1, CPS2, CPS3, Sega Model 1 and System/Multi 32, all work fantastic and may arguably make alternative emulators for those particular games obsolete. So far, some game 'drivers' that don't work well are Konami GX, Sega Model 2 and Model 3. But I know there will be more.

To get 100% performance for Konami GX you would have to go back to Mame 0.129u3 or previous. Although you may also be able to use other emulators like Nebula/etc if supported?
There are Sega Model 2 and Model 3 standalone emulators which are good alternatives if you have a decent enough computer.

I think that should be enough 'food for thought' for now.