So mame is not accurate with interlaced systems?
It is non-existent. MAME can not do interlace. We all can thank Calamity that we have a option for interlace in GroovyMAME, but like i said, that option comes AFTER the output from MAME itself.
are you saying that for a game with 60 fields per second, MAME outputs 30 progressive frames in a second? what exactly does mame do to composite the image that results in data loss?
You partially answered your own question. I dont know how much frames MAME outputs to compensate interlace, it could be 60 progressive frames or it could be 30 progressive frames. The main point is, that if the original game has interlaced output, then the fields are blended for progressive output.
EDIT: That is how MAME handles interlace and this process is destructive, till today there is no solution or blending method, that can make this process non-destructive/revertable. Once a blending/conversion is applied, there is no undo or reverting process. What is more worse is, you lose the resolution and half of the frames. This is the reason why no blending/conversion looks as good as the original interlaced frames, provided you watch this on a CRT.
One of the biggest problems for the MAME devs is, that no one use a CRT as a display, ergo they have nothing to proof with. Interlaced material can only be properly displayed on a CRT, which makes it impossible to show MAME devs a evidence, what kind of data is really lost. This may explain, why they did not care about interlace that much. What MAME needs, is a switch where a user can define what kind of output is wanted (something similar to GroovyMAME´s monitor switch). Currently all interlaced stuff in MAME, is postprocessed with blending.
So i am not a game-expert nor do i know all interlaced games, but if a game has interlaced output and it is in use other than some resolution switching for in game menues etc., then there will be data/motion lost, if outputted through MAME (even if MAME has 60 blended, progressive frames). One example i posted years ago, is Atari 2600. Play H.E.R.O and press pause in a scene with lot of motion and you will see a blended progressive frame, that originally is not there.
If someone here knows good examples for interlaced games, please tell us more
. Games that
really use the advantage of interlacing. A bad example would be a game that internally creates progressive frames and the output is interlaced, which is possible but without any benefits you usually would have. One great example is the Laserdisc game Firefox. It uses even interlaced real life footage as a background for the game.
There is more to write on that topic, but basically it is this. If there is interest, i can write more for it.