[weblacky]

I only know of one 13W3 to VGA cable on the market, the one with dip switches you can get through https://www.cablesonline.com/613mtohdmsvg.html, that works with SGI's. In the USA they also sell this cable through eBay and Amazon. You can check to see if you're in a similar situation. Otherwise the link above is for the original vendor. I have about six of these cables hopefully the never stop making them.

Every other SGI I've owned prior to this cable coming on the market used a separate small adapter and then a VGA cable. And back in my earlier days I only had one of these adapters so they were shared among all my computers.

So I'm going to conclude, in the absence of any further evidence, that what you have is a SUN Microsystems adapter cable. And I say that because pretty much 99% of all the 13w3 cables I ever encountered were actually designed for SUN.

SUN had much larger market penetration than SGI ever did. By orders of magnitude higher. So it's not unusual that their cables became the dominant 13W3 cable in the wild. It's a shame that they're not wired exactly the same. I've seen some websites that rumor that you could break off a pin or two on a SUN cable and make it work with some SGI systems. But I have no direct knowledge of this.