Build Your Own Arcade Controls Forum

Main => Main Forum => Topic started by: DashRendar on October 06, 2009, 10:47:10 am

Title: Need Advice on MAME Conversion
Post by: DashRendar on October 06, 2009, 10:47:10 am
Well, I've been reading a lot in the Wiki and the forums, but I'm not quite clear on some details.

Scenario:  I have an NFL Blitz '99 arcade, fully working.  It's a JAMMA in a Midway cab.  I would like to convert it to MAME though. 

Hardware that will be used is:

I bought an IPAC4, as one of my co-workers who has done this said that's what I needed.  Now I'm wondering if that was bad advice, and if a JPAC is really what I need.

But I'm not sure about that.  JPAC only supports 2 player, which I need 4 player.  I saw at the Ultimarc site that you can combine them with an IPAC, but I'm unclear on that.

So, I need a 4 player setup that will work with the arcade monitor and speakers in this cab.  I realize I can use an ArcadeVGA card for the video, but that's a chunk of cash.  I'm looking at JPAC as a possible solution that would be more economical.

To make it a little more complicated, I would also like to eventually hack a Dreamcast to connect up (via KVM switch maybe?), where I could play MAME games on the PC or play Dreamcast games.  That might be a factor for the video hookup.

Any advice is appreciated.   :angel:
Title: Re: Need Advice on MAME Conversion
Post by: Beretta on October 06, 2009, 01:08:28 pm
can't help you with the dream cast.. if i was gonna go with a dream cast i'd just hack some dreamcast controllers.. otherwise perhaps try emulating them instead?


the ipac has 56inputs so that is plenty for a 4 player setup..

however if you're going with 4 u360's you probably dont need anything else.

the u360's come with a 8 button interface so you'd have 32 inputs on top of the joysticks.

thats enough for each player to have their own start, coin, and 6 button layout.

but since i dont think there are any 4 player games that use more then 4 buttons.. you basicly have 4 extra inputs to spare you could use for admin controls.. IE: restart, pause, mame menu, exit, etc

as for the arcade vga, you can use a regular card and (if it's compatible) use soft 15khz this will give the you same end result as the arcade vga.


the Jpac will only filter out bad freqz it wont actually convert the video signal or anything so you'ed still need to use a arcadevga (pointless since arcadevga always puts out a proper signal anyway), and soft 15khz or other similar solution.
Title: Re: Need Advice on MAME Conversion
Post by: DashRendar on October 06, 2009, 02:48:14 pm
Yep, the plan is to hack the DC controllers for that.  Emulation hasn't yielded very good results.

I was looking at going with a Neo Geo setup- so I'd need at least 7 buttons for the first two players, plus a P1 and P2 button making 8 buttons per player.  I could get by with 4 buttons on player 3 and 4 though- so I would potentially have 6 extra buttons for admin.  That should work.

Regarding video- I've looked at using Soft 15khz, but I've read that the signal can damage the monitor if the monitor doesn't support frequencies over 15khz (before the program loads).  I'm not sure about my monitor.  It's a Hantarex Polo 25.

According to KLOV, this is a Raster Medium Resolution monitor:

MEDIUM RESOLUTION

          HORIZONTAL                    VERTICAL
Scan Frequency: 25.00 KHz    Scan Frequency: 60.0 Hz
   Scan Period: 40.0 µSec       Scan Period: 16.7 mSec
  Active Video: 32.0 µSec      Active Video: 15.4 mSec
   Video Delay:  7.2 µSec       Video Delay:  1.2 mSec
    Sync Pulse:  4.0 µSec        Sync Pulse:  0.2 mSec
     Scan Line: 640 Pixels           Screen: 416 Lines
    Resolution: 512 Pixels       Resolution: 384 Lines
    Clock Freq: 16.00 MHz

I'm unclear on whether this would work with Soft 15khz.
Title: Re: Need Advice on MAME Conversion
Post by: Beretta on October 06, 2009, 03:25:34 pm
ah most people have standard resolution monitors..

that should still work 15khz also has a set of resolutions for 25khz.

a quick and dirty way around the signal problem is to have a secondary video card and set bios to use it as the primary.. then set windows to disable the secondary card..

so when the computer boots it will dry ot display on teh secondary card, but once it gets to windows it would be disabled leaving only the primary card (the one with the monitor attached) to take over at which point it's already outputting the correct signal.

another way to do it woudl be to 1, have a seperate power switch for the monitor.

or 2. setup a relay so that the monitor is switched on once you get to windows.

some say that the 30 or so seconds before it gets to windows wont harm it but like you i'd rather play the "rather safe then sorry" card.

the jpac will work for filtering the signal before it gets to windows but it's more expensive then the 2nd card, switch, or relay solution.
Title: Re: Need Advice on MAME Conversion
Post by: DashRendar on October 06, 2009, 04:52:57 pm
I have several old video cards.  Doing an extra one disabled in Windows could work.

That is a quick and dirty way of doing it, heh.  But it might do the job.

What about hacking the arcade speakers to work with the PC?  Do they normally need juice, or it is as simple as hooking audio jack ends and plugging them into the PC's sound card?
Title: Re: Need Advice on MAME Conversion
Post by: Beretta on October 06, 2009, 05:35:39 pm
you'll need a amp.. you can either hack one from a set of cheap speakers but those are usually under 5 watts. or buy a small 50-100 watt amp from best buy, etc.

someone posted a 20 dollar amp on ebay think it was about 60 watts that would do the trick, do a search it was'nt to long ago.


some sound cards have a onboard amp.. but those are usually only about 2 watts, so normally you will need amp, most sound cards would'nt be able to drive the speakers directly.
Title: Re: Need Advice on MAME Conversion
Post by: bkenobi on October 06, 2009, 09:02:06 pm
The cheap amps are T-Amps.  I've read good things about them, but don't expect them to perform like a $$$$ unit.  They are simply a very competent single channel stereo amp.  They sound good but won't drive anything huge.  Of course, this is a perfect application if you are talking smaller speakers (4.5" arcade speakers for instance).
Title: Re: Need Advice on MAME Conversion
Post by: DashRendar on October 07, 2009, 10:22:52 am
I do have an old 5.1 speaker and sub set, but that seemed like overkill for an arcade cabinet.  It would be easy to interface with the PC though, but I actually think the original arcade speakers are great quality, and was hoping to keep them.

But I'd rather use that then buy another piece of hardware (amp).  Spending too much money as it is!   :dizzy:

I'm guessing MAME games can only take advantage of 2 speaker stereo, right?  IE, no sound would be coming out of the other speakers in a 5.1 speaker setup?
Title: Re: Need Advice on MAME Conversion
Post by: Beretta on October 07, 2009, 12:47:24 pm
ya i dont know of any games that had surround sound.. maybe something really new like > 2000 maybe games like DDR (never actually played one)

anyway if you're only using stereo you should still get sound out of all of them.. it's just there will only be L and R not front left, rear left, etc

you could buy a few cheap sets of speakers.. sometimes you can get them for a few bucks online.

then take the amp out (usually a little DIL chip), might take 2 or 3 depending on the power of the amp most are only a few watts.

you might as well pick up a amp on ebay for say 20 bucks.. because if you're not gonna use that 5.1 setup you got then you're gonna be buying another set anyway.

it sounds like you really wanna use the original speakers so i think you would be the most happy just buying a small amp.
Title: Re: Need Advice on MAME Conversion
Post by: bkenobi on October 07, 2009, 01:07:25 pm
I personally disassembled an old 2.1 set of PC speakers.  I just wired my cab speakers up to the amp and kept the sub as is.  It sounds fine for what I use it for.  The other cab I just used the speakers on the TV.  I originally was going to install dedicated ones, but that is an Area 51 cab and it doesn't have any other place to put the speakers (HUGE glass from CP all the way to the top...speaker was originally in the CP).

Anyway, if you are going to buy something (PC speakers or amp), you would be better off with the amp IMO.  The impedance of most speakers is different than what PC speakers use.  Also, you will probably spend ~$20 shipped for a set of speakers.  You could instead spend the same amount on a decent quality amp (for the purpose) and you won't have any issues.  Your call...  :dunno
Title: Re: Need Advice on MAME Conversion
Post by: tep0583 on October 08, 2009, 01:28:58 pm
I looked into several ways to use the original speakers, but ended up just buying a cheep set of Creative 2.1 computer speakers for ~$20. They fit fine behind the speaker grills in my cab and sound really good. The sub, while small, adds enough kick as it reverbs through the cab to add a nice quality to the sound.

They won't blow your eardrums off, but they're plenty loud for the application.

I can't find the exact speakers I have, but they were somewhat like these. http://us.creative.com/products/product.asp?category=4&subcategory=27&product=461

The remote volume control was a real plus. I stuck that in the coin door and I can turn them off, on, or adjust the volume easily from the front of the cab.
Title: Re: Need Advice on MAME Conversion
Post by: Beretta on October 08, 2009, 01:41:02 pm
ah, ya remote volume control is definitely nice the set i got im in the middle of hacking it apart it was built into the base of the left speaker.. a remote volume box sure would have simplified things.

bad thing about speakers is you never really know what they sound like till you get them home that's why i went with CA (from previous exp) although they kinda let me down this time around. quality/power has dropped on their cheaper sets although they're still good value at mid range.
Title: Re: Need Advice on MAME Conversion
Post by: tep0583 on October 08, 2009, 02:18:59 pm
Very true.

I reasoned the Creatives would be at least decent and was pleasantly surprised. Got lucky there.

I also reasoned that the 2.1 Altec Lansings would be OK and were my back up plan, if the Creatives were junk. They didn't have remote volume, though and that IS pretty nice to have.

Title: Re: Need Advice on MAME Conversion
Post by: DashRendar on October 09, 2009, 10:12:05 am
Great idea about the remote for sound.  That actually brings up an idea I had before...

My cab is in my basement.  About 20' away is my big screen TV and home theater (with surround sound).

I kicked around the idea of running an audio cable from the cab to the home theater.  This would let me control the sound with a remote, give me a lot of power through the subwoofer, not to mention letting me setup a jukebox on the cab for when I have people over.

Not sure if anyone's done anything like that, but the one downside is that the TV wouldn't get sound if I'm playing games/music on the cab.  Meh.