[rescue] I got a new Octane! Why can't I talk to it?

[der Mouse]

> The machine is set to boot from graphics and you are trying to
> connect to a non-13w3 monitor using a Sun (or one labeled
> Sun/SGI/DEC) 13w3->HD15 adapter.

> The coaxial bits of the 13w3 connector (the w3 part) are reasonably
> standard across vendors.  The stuff in the middle (the 13 part) is
> not.

There are actually only 10 pins in the middle.  (One glance makes it
obvious the number is even, and it's not hard to count the pairs and
find there are five of them.)  I believe the 3 in W3 gets added to the
10 to give the 13.  (There's a somewhat similar connector, in a DA
shell I think, with just the 3 co-ax connectors, which is called 3W3.)

> So, if your adapter works with Suns it likely won't work with an SGI.
> I've found that many monitors are confused if, say, they are
> recieving H sync on one of the Monitor ID pins.

It's also not quite that simple in any case.

I recently dealt with an interesting case.  I have three 13W3-to-DE15
adapters.  Two, let's call them A and B, are pigtail style and need to
be used with a 13W3-to-13W3 cable; the third, C, is a cable with 13W3
on one end and DE15 on the other.

I was using A at home, with a Sun 13W3-to-13W3 cable, connecting a Sun
SS20 onboard framebuffer to an Acer flatscreen.  I was using B at work,
with another Sun 13W3-to-13W3 cable, connecting a Sun LX to a Dell
flatscreen.  I was using C at my gf's place, connecting a cg6 in a Sun
SS5 to another Acer flatscreen.  All worked.

Then I tried to replace the SS5 with another LX.  No joy.  After some
experimenting, I found that C's pinout was different from (at least)
B-plus-cable's, and presumably the LX onboard framebuffer is different
from the cg6.

I found that C worked with the SS20 at home, so it's all straightened
out now, but it does say that things can vary even within a given
manufacturer's products.

> A quick fix to the above problem, assuming you are sure that your
> monitor supports Sync on Green and you are willing to commit an
> adapter to this purpose, is to snap off the 13 pins in the middle.

Well, 10 pins, but yeah.  This works only if both the video hardware
and the monitor do sync-on-green (the former may be true of all SGIs
for all I know).

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