J-Pac / I-Pac

[chris2922]

Could someone please explain to me what the difference is between the J-Pac and the I-Pac.  I was going to buy a J-Pac and an ArcadeVGA to interface my JAMMA cab to a bare bones Pc.  Before I do though, id like to know what the difference is.

[SirPeale]

They're both the same for inputs.  The J-PAC has the added functionality of being able to plug directly into a JAMMA harness.  It amplifies the video signal to a level the monitor can use. 

[krick]

The J-PAC also has a video circuit that divides a 31KHz VGA signal so that it cannot damage your arcade monitor if you accidentally send it a VGA signal.

This is most useful for people running DOS cabs with AdvanceMAME and a "normal" (non ArcadeVGA) video card.

When booting with a normal video card, there is a brief period during the BIOS display where a 31KHz signal comes out of the card.  Then when AdvanceMAME loads, it reprograms the card to display a 15KHz signal.


Since my cabinet was already wired for JAMMA, I went with a J-PAC and an ArcadeVGA.  I also picked up an additional I-PAC2 so I could hook up the player 3 & 4 controls, and an Opti-PAC for the trackballs and spinners.

[chris2922]

Great, sounds good.  I'll get on and order them then.  Thanks both.

[paigeoliver]

Since I first used the Jpac I now reccomend them for everyone, not just people using arcade monitors. Wiring is simple and easy with a JAMMA harness. Not to mention a lot less fragile. Plus the J-Pac makes swappable panels a breeze.

If you have a J-Pac and a Bob Roberts JAMMA harness then you won't even have to THINK, as every wire will be labeled for you.

[pcates]

The J-PAC also has a video circuit that divides a 31KHz VGA signal so that it cannot damage your arcade monitor if you accidentally send it a VGA signal.

Since my cabinet was already wired for JAMMA, I went with a J-PAC and an ArcadeVGA.

[iwillfearnoevil]

I did not think you needed an arcade VGA if you got the jpac. I thought it handles the signal for the arcade monitor. Am I mistaken??
Thanks,
Patrick

the j-pac just makes sure the signal is at 31mhz. if your video card is not at 31mhz it just won't let a signal through. you can use lots of video cards if you are okay running advancemame in dos or there's powerstrip for windows that lets you run at a different frequency. check out this page for some various video card reviews for mame plus more info you'll prolly find helpful.

edit: thanks for the correction peale. i was on autopilot typing that up

[SirPeale]

the j-pac just makes sure the signal is at 31mhz. if your video card is not at 31mhz it just won't let a signal through. you can use lots of video cards if you are okay running advancemame in dos or there's powerstrip for windows that lets you run at a different frequency. check out this page for some various video card reviews for mame plus more info you'll prolly find helpful.

You got it backwards - it makes sure the signal is @ 15KHz, not 31. 

[krick]

I did not think you needed an arcade VGA if you got the jpac. I thought it handles the signal for the arcade monitor. Am I mistaken??
Thanks,
Patrick

Technically, you don't.  However, bear in mind that the J-PAC is not a video converter.  The signal divider feature is just a safety device to protect your arcade monitor.  You still need a video card capable of being reprogrammed to output a 15KHz signal.

Check out the "Hardware" link on EasyMameCab for more information...
http://easymamecab.mameworld.net/

[danny_galaga]

Since I first used the Jpac I now reccomend them for everyone, not just people using arcade monitors. Wiring is simple and easy with a JAMMA harness. Not to mention a lot less fragile. Plus the J-Pac makes swappable panels a breeze.

If you have a J-Pac and a Bob Roberts JAMMA harness then you won't even have to THINK, as every wire will be labeled for you.

yes, yes! i like not thinking! that's completely gelled my plan for my upright then...