Arcade captures!

Basically not long after I got my Neo Geo cabinet I jumped on the waiting list for the NAC Splitfire, something I could use to capture video from it. I’m still on the waiting list for that, but in the mean time I looked at a few other options. First, I could just throw some resistors on the RGBS lines and hook it straight up to my capture card… some folks have done this but this seems super dodgy, I don’t know enough about electronics to say why (I basically know that “decoupling” is a word and that’s about it) but I decided not to risk destroying either my Neo Geo board or my capture card (or my OSSC).

Second, someone on one of the local arcade forums was selling the RGB->S-video adaptor board from a Point Blank, which would basically do what I want (I have an S-video capable capture card), but they refused to separate it from the pile of other stuff it was with, and while I thought about whether I wanted a heap of coin mechs and shit, someone else bought the lot.

Finally, a couple of weeks ago I found that someone had built something very similar: the Betsu Betsu (which I think is Japanese for “similar”?) which also does what I want: takes the RGBS output from the JAMMA edge, passes it through to the cab, but splits it off to a video amp, along with taking the audio and sends it through a transformer as well. After following the thread on Arcade Projects I was reasonably satisfied that it met my requirements. I thought about buying a board and building it myself, but I would have to deal with getting the individual parts, plus waiting for them to ship internationally, but instead I found someone local to sell me a built one. Unfortunately this person later made some really questionable comments about copying of other folks’ work, so despite the fact he apparently donates a share of the betsubetsu proceeds to the creator, I’m not going to link his store.

Anyway, it arrived today and I set it up. It took a bit, I thought at first it may actually have been defective, but it turns out the OSSC just needs a couple of minor settings changes to pick up the sync signal from the MVS (mirrored here from JunkerHQ’s MVS page):

Sync Opt -> H-PLL Post-Coast: 2 lines

Sync Opt -> Hsync Tolerance: 8.30us

Once I did this, I got a sync, and then I set about getting the picture correct. My capture card does not like the Line2x mode (regardless of output mode) from it, but Line4x and Line5x look great. Line5x looks slightly better, but some of the image is cut off, so I settled for Line4x.

After some tinkering to get the colors right (I’m still not happy with it but it’s close) and positioning the webcam for an unfortunate crotch-shot (trying to get the controls in frame), I was able to start recording:

Metal Slug!

Unfortunately nerves got the better of me and I didn’t put on a particularly good show, so I didn’t save the recording. Maybe after a few practice recordings I’ll turn in something reasonable!

I still haven’t worked out if I’ll take myself off the list for the Splitfire or not - some folks reported easier times getting arcade boards to sync with it than the betsubetsu so maybe it might be a benefit to have two just in case?

As my MVS board is mono, and basically the worst case scenario for stereo conversions (some are very easy to convert, actually having a stereo op-amp on board), and my cabinet is mono anyway, I opted for the splitter to be in a mono configuration too. I figure if I get anything like a Naomi (on my wish list) it’ll have RCA output for stereo anyway, so I can just swipe from there if I want stereo audio… but for what I’m doing now I don’t think I care about stereo captures.

I can see this weekend being a pile of fun though!

Horsham, VIC, Australia fwaggle



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Horsham, VIC, Australia

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