SGI: Hardware

Hi there,

I changed my old but very good CRT for a new acer p243w LCD (24", 1920x1080 max res).

When the octane boots, the display begins to flicker, something like one image per 1 or 2 second. It does not stop when logged in. But the image I can see is quite good !

I tried to change display properties (different resolutions and frequencies) but didn't manage to stop the flickering (except killing my vision).

I do not understand what happens. The display on my CRT was quite correct.

My config is:

Octane/R16K 600MHz/2 Go ram/V12.

I use a 13w13-HD15 adapter.

Any idea ?

Thanks...

yungjoon

I had the exact same thing happen when I tried my octane with a dell P780. It does work fine on that display's bigger brother, the P990. I think the consensus is that you need a real designed-for-SGI 13w3 to vga adapter and not one made for a sun.

sybrfreq wrote: I had the exact same thing happen when I tried my octane with a dell P780. It does work fine on that display's bigger brother, the P990. I think the consensus is that you need a real designed-for-SGI 13w3 to vga adapter and not one made for a sun.

Why is this ? Just curious...

I'm tempted to designate the same suspect; I had very important/weird flickering on my philips 190V TFT, using an unknown origin 13W3/HD15 adapter on the Onyx2. I replaced it by a "pin stripped" sun adapter (the 190V is SOG), and now everything works perfectly. I even use the previous adapter on the second channel of the DG5 with a non SOG TFT without any problem.

bplaa.yai wrote: I'm tempted to designate the same suspect; I had very important/weird flickering on my philips 190V TFT, using an unknown origin 13W3/HD15 adapter on the Onyx2. I replaced it by a "pin stripped" sun adapter (the 190V is SOG), and now everything works perfectly. I even use the previous adapter on the second channel of the DG5 with a non SOG TFT without any problem.

I stripped the pins and the same flickering remains. I wouldn't call it a flicker though, more of a flash on / off each second or two. However both the 780 and 990 are CRTs so YMMV.

jsloan wrote:

sybrfreq wrote: I had the exact same thing happen when I tried my octane with a dell P780. It does work fine on that display's bigger brother, the P990. I think the consensus is that you need a real designed-for-SGI 13w3 to vga adapter and not one made for a sun.

Why is this ? Just curious...

Because the sun adapters do not route the separate sync signals (through the smaller pins) properly with a sgi machine. Some SOG monitors are confused when sync is on both the h/v pins (or whatever they pin out to with the wrong adapter) and the green pin, and if you strip out the h/v pins then it can recognize the SOG properly. Other monitors need the separate sync pins properly wired.

I can't speak to any problems you might have with a CRT, but LCDs can be very particular about the timing parameters on their VGA input. When I was making a vfc for my 20" Dell, my first try had some weird banding problems where IIRC every third row was sort of interpolated from the neighboring rows. It took some trial-and-error tweaking on the vfc timing parameters before I got it fixed.

The root of the problem is that IRIX uses its own hard-coded timing parameters for each resolution, instead of reading the monitor's EDID and sending out what the monitor likes to receive (which is what other OSes do). It probably doesn't have anything to do with the physical connection (sync pins, etc.). To fix the problem, you probably need to find out the monitor's timing parameters from the EDID, and make a vfc with them. Reading the EDID isn't real easy, but can be done from Windows or Linux. Making a vfc is similarly not easy.

Many thanks for your replies.

I have an adapter I used formerly with my sun ultra30. Strangely, I used it with my Octane/19"CRT without any problem.

Sometimes, I see adapters on ebay but I can't know if they can do with my LCD monitor.

Hey, if someone has a spare adapter to sell, I am interested !

yungjoon wrote: Many thanks for your replies.

I have an adapter I used formerly with my sun ultra30. Strangely, I used it with my Octane/19"CRT without any problem.

Sometimes, I see adapters on ebay but I can't know if they can do with my LCD monitor.

Yes, it's very difficult to find the proper adapters, and know what you're getting for sure.

yungjoon wrote: Hey, if someone has a spare adapter to sell, I am interested !

International shipping might be an issue, but Greg Douglas at Reputable Systemes http://www.reputable.com sells them. http://store.ultraspec.us/1395-sgi.html also appears to be the right one.

http://www.deepspacecables.com/models/octane.html

cybercow wrote: http://www.deepspacecables.com/models/octane.html

Great to see their website back up! This used to be the place I recommended most highly. I had great results with their adapters (solved all my KVM problems) and bought in bulk. However, other people here had complained that their service was non-existent and never got the adapters they ordered. The website had been down for more than a month. I would email and confirm that they are back in business before ordering anything (and they operate an eBay store where the prices are cheaper!), or order from the other sites I listed earlier.

I confirm this, deepspacecables seems to be off.
I tried to order something and no payment procedure was available.

That's a pity...

Hi,

I found this:

http://cgi.ebay.fr/SGI-13w3-VGA-HD15-Ca ... 240%3A1318

Does it work for LCD display ?

Thanks...

yungjoon wrote: I found this: http://cgi.ebay.fr/SGI-13w3-VGA-HD15-Ca ... 240%3A1318

Does it work for LCD display ?

I got essentially the same 018-0881-002 cable with the Octane2 I brought from SGI. It has worked with a V8 and a V12 when connected to a Dell 2407wfp, and also works when connected from the 13w3 port on an Onyx300 to the HD-15 port on the same 2400wfp and a Dell 1800FP. viewtopic.php?f=3&t=16720118&p=7293104&#p7293104

Hi. Try to change the sync signal source in display's channel manager. I do not have irix box here now, but i remember it helped with my LCD and onyx2 case.


regards
pawel

I confirm SGI 018-0881-002 is ok.

What a big desktop !

Thanks all,

yungjoon.