First time monitor help - Billabs 25" BL25C90T Edit: ready to start, concerns

[Osirus23]

Hi,

My MAME cabinet is almost done and I'm getting ready to use my arcade monitor for the first time. The monitor is a 25" BL25C90T. I have a few questions first since I don't want to break anything because I hooked it up wrong. The "documentation" it came with didn't contain much information.

The monitor's video input is a 15 pin D-Sub so there shouldn't be a problem there, my first question is on the AC input.
The AC wires that came with the monitor is just a Y-adaptor that plugs into the 3 pin jack on the monitor, so I'll have to hack my own AC cord from a PC cord. The monitor's harness has 2 purple wires and 1 green in the center. I'm assuming green is ground, so do the positive and negative matter on how I wire them?

Second, the monitor has a Video Input Impedence Switch (75ohm / 1kohm.) I will be using an ArcadeVGA card in my PC, so which setting should this switch be set to?

[grantspain]

75ohm for 31khz signal
1kohm for 15khz and 25khz signal
so if you have the avga card set on 15khz then you need the sitch set to 1kohm

ac wires don't really matter how they are wired as long as you get the earth correct you should be fine

[Osirus23]

Thank you.

Would I need an isolation transformer with this monitor? It's brand new.

[grantspain]

you have a wei ya m31 series monitor
it is classed as a free range monitor,which basically means it runs from 85vac to 265vac direct from the mains supply.the chassis has a smps thus not requiring an isolation transformer
this monitor also auto sync's to whatever frenquency you supply it,for example you can run it on 31khz vga all the way down to 15khz cga without the need to do any modifications(apart from the 75ohm/1kohm switch)

I have the rodotron 666a chassis which is almost identical

[grantspain]

just one word of warning,do not send this monitor a higher resolution than 31khz as it will fry the horizontal output transistor

[Osirus23]

31kHz = 640x480 right?

[grantspain]

31kHz = 640x480 right?

perfect

[Osirus23]

Update:

The MAME computer has arrived and is all set up now, currently using a CRT PC Monitor. AVGA drivers and Tri-sync patch are installed. The PC monitor is connected to the DVI port on the AVGA.

Is it always safe to connect the arcade monitor to the D-sub on the AVGA card? I'm ready to hook it up but don't want to send it a signal that could damage it. According to my monitor, the display from the card is always over 31kHz, and I've tried many resolutions in quickres. Will the signal from the D-sub connector be lower?

[grantspain]

avga card should out 15khz only from the d connector,you should be good to go

[Osirus23]

Got it running at 640 x 480 now. Seems to work ok. With the tri-sync patch its going 31khz which is just fine for this monitor. The games look great, even with hardware scaling. I had intended to run them in native resolutions but readjusting the monitor each time is a little too tedious.

One more note, the BIOS screens are I think 800x600. If I'm using the AVGA is it safe to have them on the monitor or should I wait until XP boots to turn on the monitor?

[grantspain]

your monitor should run fine on res lower than 35khz,i think you are being too cutious

[Ummon]

Through the 'arcade out', the bios screens are 15khz. If you don't want to seem them at all, refer to my thread on 'using a PCI card....'

[Osirus23]

I don't mind seeing them, as long there's no hazard of damage its fine.

[ahofle]

So this isn't a digital monitor then....bummer.  What happens if you feed a 31khz (VGA) resolution to it when the impedance switch is set to 1kohm?

One benefit to using Soft15khz over the AVGA is that you can easily limit the resolutions over VGA (or make them interlaced).  With the AVGA and the multisync patch, you can go all the way up to 1024x768 progressive so you'll need to be careful.  Another benefit of Soft15khz is that you can run 1024x768 interlaced @ 25khz with that monitor (and some other nice resolutions like 432x324 and 416x312 for some newer vertical shooters).

[Osirus23]

I started this project back in March of last year and ordered the AVGA before Soft15khz was available. I wish I had a digital monitor now; the AVGA is kind of pointless since I have to always run 640x480.

[ahofle]

since I have to always run 640x480.

Do you?  Why can't you run CGA resolutions and use interlaced for 640x480 and higher?

[Osirus23]

I could run lower resolutions but since I have to readjust each time the res changes I just leave it at 640x480.

[ahofle]

Do you have to readjust at different CGA settings?  Or just when you go from CGA to VGA?

[Osirus23]

Good question, like I said I don't have a lot of experience with this, but here's what I just tried:

1. Configured MAME.INI according to Ultimarc's instructions for AVGA.

2. Loaded Mortal Kombat II and adjusted picture to fit. Closed

3. Loaded Metal Slug X, picture was not adjusted correctly. Closed.

4. Loaded Mortal Kombat 3, picture was unreadable and had bad horizontal sync problem.

No adjustments were made after MKII was set to fit. I believe these games all used CGA resolutions. The desktop was still set to 640x480. I think I'm slowly learning here but its confusing to me.

[ahofle]

OK a few things.  If you want to try going CGA, you should uninstall the tri-sync patch.  Otherwise your desktop is VGA and your games are CGA, thus the need to reset everything every time you exit a game and start a new one.  With the tri-sync removed, your desktop will be be interlaced (but still 640x480).  You should then only need to adjust the size once.  But here's the other thing: you need to adjust your monitor for a 256 line or so game (like Mortal Kombat).  240 line games like Metal Slug will then not completely fill the screen and will have small black bars on top and bottom.  You should leave it like that.  If you adjust the monitor to fill the screen for metal slug, then the next time you start a 256 line game like MK, it will overscan.  You have to pick a 'middle of the road' that works for most games unless you want to constantly adjust.  This is why digital monitors are better for emulation because you can have pretty much all games fill the screen.

[Osirus23]

How do I uninstall tri-sync? I've done a search but come up with nothing.

[ahofle]

Just a guess, but you probably have to uninstall the AVGA drivers completely, reboot, and reinstall.  May be worth checking with Andy at ultimarc just to be sure though.

[ahofle]

Before you uninstall the AVGA multisync patch, can you try something?  Run metal slug, and adjust the screen to roughly fit.  Then exit to the desktop (which should be VGA).  Do you have to adjust again just to see the desktop?  If not, then forget what I said about uninstalling the multisync patch.  You just need to pick an adjustment that works for most of your CGA games.

[Osirus23]

Did what you said, when I exited back to the desktop I could still see it but it was no longer aligned and fit like it was.

[Ummon]

I think the patch will show up in 'add/remove' programs.

[Osirus23]

I think the patch will show up in 'add/remove' programs.

It doesn't 

[Ummon]

I think the patch will show up in 'add/remove' programs.

It doesn't 

Ahofle, do you remember on this?

[ahofle]

Nope I don't remember since I never had to uninstall it.  I suggested to remove the entire AVGA driver and reinstall it (or contact Andy).