Losing sync with Groovymame, arcade_15--question about HsyncPulse

[bulbousbeard]

I have an unidentified 15khz arcade monitor, and I'm using Groovymame with the arcade_15 preset and a JPac.

I'm randomly losing sync, and I have to unplug and replug in the JPac to get sync again. I'm not sure whether the JPac is defective or the presets don't work on my monitor.

Andy from Ultimarc says that this is a common issue due to the width of the sync pulses being too narrow. If this is the case, I should be able to take the arcade_15 preset and increase HsyncPulse, right? Its default value is 4.700, I think.

I'm assuming that the values below are the same as arcade_15, but I'm not sure how much to increment HsyncPulse by. Please advise.

monitor custom
crt_range0    15625-16200, 49.50-65.00, 2.000, 4.700, 8.000, 0.064, 0.192, 1.024, 0, 0, 192, 288, 448, 576

Thanks!

[Calamity]

I do have the exact same issue here, but only with one of my two jpacs (the newest one, bought in 2008). I always assumed it was related to the jpac's board not receiving enough power from the usb, as I have noticed it happens more often when I have several usb devices connected. If you have success  increasing the sync pulse width, please report back. I'll give it a try myself, though I'm somewhat sceptic.

Yes, those are the arcade_15 values, try increasing h sync pulse to 5.000 or 5.200, etc.

[bulbousbeard]

Calamity, thanks for the reply.

I think you're right, because what I noticed is that when it goes out, it's not like it's losing sync. It's more like it just isn't getting any power because the controls don't work either. It's literally as if you unplugged the J-PAC. Well, I'm getting another one this week, so we'll find out.

Thanks for the tip on the HsyncPulse...I'll see what happens.

[bulbousbeard]

Yeah, adjusting the HsyncPulse doesn't do anything for me. Did you have any luck with it?

[Calamity]

Yeah, adjusting the HsyncPulse doesn't do anything for me. Did you have any luck with it?

I suspected that. I couldn't try it anyway.