MAMEWorld Forums - Ultimarc - Re: AVGA 3000, J-PAC, Blast w/ Nanao MS-2933 and Tri-sync setup

> I'm not understanding what you're wanting.

Perhaps I'm way off base, here's my understanding of the J-PAC based on https://www.ultimarc.com/jpac2.html

The pattern of DIPs do the following (where the first is the one labelled 15kHz, second is the 24kHz, and third is the 31kHz. 1 is jumper present, 0 is not):

* 0,0,0 - no filtering of vert freq, no messing with sync. Assumed Composite in/out.
* 1,0,0 - allow _only_ 15kHz through. Convert Hori/Vert sync to Composite
* 0,1,0 - allow _only_ 24kHz through. ""
* 0,0,1 - allow _only_ 31kHz through. ""
* 1,0,1 - allow only 15kHz through. Convert Hori/Vert sync to Composite. "Divide line frequency by 2" (AKA resampling the vert sync).

What I'd like would be to allow 15,24,31kHz through (or anything, frankly, would suffice), but to do the Hori/Vert -> Composite sync, inversion etc.
(now I'm wondering is 1,1,0. 0,1,1 and 1,1,1 do anything useful and undocumented).
Edit: 1,1,1 certainly doesn't - it behaves the same as 1,0,1 as you might guess.

I guess the reason this isn't common is people either have a single-sync monitor, or they have something much more modern that takes a VGA signal and they can skip a J-PAC/JAMMASD entirely.

> Also, it doesn't sample anything; it allows signal through or not.
Yes, yes it does. See above. It samples the sync. The Video signal is left untouched though.

Edited by Tourniquet (06/21/15 11:41 PM)