Comp neg sync, horizontal sync, vertical sync?? I'm comfused.

[mmarx82]

I'm thinking of purchasing a monitor (specifically a Dotronix DSV27) with a db9 connection with the following pin outs:

Pin 1 -- Red
Pin 2 -- Green
Pin 3 -- Blue
Pin 4 -- GRD
Pin 5 -- GRD
Pin 6 -- Comp. Neg Sync
Pin 7 -- N/C
Pin 8 -- N/C
Pin 9 -- N/C

what is confusing me is Pin 6. From my research I know that pin 6 is carrying my horizontal and vertical sync's.  It was suggested by one member who also has this monitor to connect this pin to pins 13 and 14 on the VGA pinout. However the member has not yet purchased a ArcadeVGA card to see if it works. and the member gave me this link: http://pinouts.ru/Video/VGAVesaDdc_pinout.shtml which shows in the diagram that the composite sync should be hooked up to pin 13, not pin 13 and 14. Is his information of hooking it up to both pins correct?

Also, does anybody else have this monitor, and if so how is the picture quality and what is it's max resolution.

Here is a link to the manual if it will help someone to help me. http://www.dotronix.com/pdf/01054dsvusermanualp.pdf Page 9 has the pinouts, it is page 8 that makes me think that I don't need to hookup pin 14 according to the manual.

Another question I have is, do you guys think this cable will work to hook the monitor up to the component connections which the monitor does have. http://www.nwca.com/index.cfm?fuseaction=products.showDetail&header=CABLES&subheader=DVI&productID=4585&flag=Standalone What would be better if so? I'm such a noob.

What do you guys think?
Thanks in advance.

[MonMotha]

Some PC video cards (I have no clue about the ArcadeVGA) can actually output composite sync on their own.  It would be on the horizontal sync (VGA pin 13) line which you can then connect directly to the monitor.  Those cards will also usually let you control polarity to get active-low (negative) sync.

If you can't get composite sync directly from your video card, the correct way to do it is XOR active high vsync with active low hsync.  You can do this with a 74[LS/S/CT/HCT/VHCT]86 chip (including using an extra gate to invert hsync since VESA says they should both be active high for PC video).  In reality, you should never connect the two sync OUTPUTS together (connecting a single composite sync output to two separate H/V inputs is fine and often does what you want, in fact).

Of course, the above paragraph assumes your monitor wants "TTL Level" (5Vpp, 0V referenced) sync signals.  If it wants sync signals at the same amplitude as your video signal, you have to get slightly more creative (74LVX86 will often work, depending on the amplitude of your video signals), especially since PCs always output TTL level sync.

[AndyWarne]

The ArcadeVGA card always sends negative sync on H and V which means you can connect them both together and get composite sync.
Andy

[mmarx82]

The ArcadeVGA card always sends negative sync on H and V which means you can connect them both together and get composite sync.
Andy

So, what I was originally told is correct?
I can take pin 6 on the monitor, split it and connect it to both pins 13 and 14 on the vga card?

Sorry that I'm re-asking the question but I want to be absolutely sure.

[Thenasty]

just take pin 13&14 twist it together and connecto your pin 6. Don't split pin 6 and connect one to 13 and connect the other on 14.

[mmarx82]

Ok, thanks for the advice guys!!

[mmarx82]

Do you guys think this cable will have a better quality than S-Video? It's a DVI to Component cable

http://www.nwca.com/index.cfm?fuseaction=products.showDetail&header=CABLES&subheader=DVI&productID=4585&flag=Standalone

[AndyWarne]

It would be better but hopefully this is not related to the original question otherwise there is some confusion going on!
Andy

[Rickn]

Comp Neg sync...
This means that both the vert and horizontal sync are on one wire from the game. Usually you can tell by counting the wires if 5 wires then Red, Green, Ble, Ground and composite sync.
If six wires then same as above but one wire for vertical and 1 for horizontal sync.

Most monitors are negative goig, with exception to the "Good old days" people like Midway, Balley ... sometimes use d positive going sync.

Hope this helps but do not hesitate to ask.
Rick@niemandisplays.com

By the way If we do not have the right monitor, I will still try to help

[mmarx82]

It would be better but hopefully this is not related to the original question otherwise there is some confusion going on!
Andy

No, no,. not related to the original question. Just tryin to get an idea of how I want to go about this for the big picture. See, the monitor I am looking at accepts both the DB9 and component input, no others. I needed to see what was involved to get it done right and have the best possible picture. I'm also still throwing around the idea of using a TV as well, which would also have component input.

Thanks everyone.


EDIT - To have the best possible picture and be able to play some PC games on the cab as well. Which means support for 600x480 and 800x600 or larger while still being able to hit those native resolutions in mame.