Yo,
I just came into possession of several of these sets that need cosmetic restoration (Keyboard and mouse system's proprietary mouse and metal M3 optical pads).
This kind (but with the mousepad you need):
https://www.worthpoint.com/worthopedia/s...-271230831
These are using personal Iris style DB9 connectors :
https://hardware.majix.org/computers/sgi...ards.shtml
So you'd need to make cable for the DB15 style. The cables I got where DB9 to MinDIN style for Iris Indigos, so again you'd need to make a proper DB9 to DB15 cable but this site link above tells you the correct pinouts for that. I'm not ready to post them, but be assured it's on my list and I plan to post them here.
Now the reason I posted this statement at all, if you look at the Old 4D FAQ, you'll see that the author complains these keyboards were over his budget of $100, and that was in the early-mid nineties! (25+ years...so account for inflation at least.) I haven't even seen of these in person (until I bought out the dregs of a suppliers that need some love and filled in the rest myself) for 20+ years, I've not seen one on eBay for many many years.
So they aren't cheap. $100 is not even half of what people (nor I) will be asking. If you just need a working keyboard and mouse, please go try to get the Indigo keyboard and mouse adapter to USB HID adapter and wire the minidin to DB15 cable yourself. They used to be sold on eBay but recently the guy making them said he was stopping, I bought one out of caution, you may still be able to find one from somebody. Looks like his site has 3 more in stock (he said last year that when they are gone, they are gone...so buy it now)):
https://drakware.com/product/IndigoUSB
With his adapter, you should be able to get going for under $100 in both the adapter and connector supplies to make the cable you need. Then you can use use a USB keyboard and mouse and get on in life).
If you are a collector, and want the "right" keyboard and mouse setup that works to complete the expensive and original item (Crimson, 4D Iris, etc) Then you'd want the original and correct hardware you're asking about.
The keyboard and mouse have been designed to use 12V differential signalling (I assume for extremely long cable lengths to get you away from the originally loud machine into the next room). The keyboard alone (working and cosmetically in great shape) is about $150+, the mouse you have to use (whether you can get an original or a clone) is about $100, and the optical pad (in great/VG shape) will run you about $85+. So for a complete original set of the keyboard, mouse, and optical pad, you'd be in the area of $335+ based on functionality and condition. These were only used on a coupled systems, the Indigo adapter was designed because these cost so much 20+ years ago that no one could get them, the adapter solved that issue for people who don't care if they had the original peripherals or not.
So this was just for your FYI, this isn't an "eBay prices are going up" thing...prices were this high for what you're asking for decades ago (if you factor the dollar's value in the early 90's at least, not accounting for scarcity on top of that).
Since mine need elbow grease and real cleaning, and I need to fix my Indigo to test them, and after oxidation and cleaning, I intend to start around $350 for a complete peripheral set "ready to use" (not including S&H). So please alter expectations accordingly.