Build Your Own Arcade Controls Forum
Main => Main Forum => Topic started by: chris2922 on January 10, 2005, 01:42:37 pm
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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.
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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.
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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.
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Great, sounds good. I'll get on and order them then. Thanks both.
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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.
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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.
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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 :)
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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.
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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/
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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...