I believe that this thread has been missing here for a while now. The problem of Indigo (1) and other old SGIs without a compatible keyboard came up in different places on the net every now and then, but the answers have become more and more negative, hopeless and sparse. I've been looking for a solution to this for a while myself. I think I probably saw the last original older SGI keyboards sell on ebay about two years ago while I was waiting for a cheaper opportunity to come up. It never did and now there aren't even keyboards to buy that could be used to reverse engineer the protocol or record the signals. I haven't seen any adapter offered anywhere in the time since I'm looking for one. So, thank you,
@megaimg, for getting this rolling again.
Oh, wow. I wasn't able to find those hex files anywhere. I only came across copies of (parts of) that page with dead links. Now that I know that they were in that wiki, they seem easy to find. Thanks for posting the link!
2x microcontrollers seem completely unnecessary. I'm pretty sure a single MCU can handle both keyboard and mouse easily.
Please be aware that even the slightest lag can be noticeable and a great annoyance to some people. Especially with the mouse it's important to have no lag. Apparently this is a problem with USB adapters. Hopefully not for simple serial-to-serial adapters. So, you're probably right.
Of course I don't mind if the design is improved upon. (Both hardware and software aren't perfect.) But I also hope that nobody gets discouraged to make one of these, in any working version and form factor, by critical posts. I'd be happy with a hardly working, crappy built pile of badly soldered leftover components. As long as it does anything it's infinitely better than what I have now: Only incompatible keyboards.
I could probably built one of these myself. But it's been 20 years since I've programmed a PIC in school and this would be my second time. I don't have as much time for additional little projects like this as I'd like to have. So I'm in the market for a working PS/2 adapter for my Indigo. Just letting everybody know in case somebody makes more than they need.
I haven't been receiving email notifications from this forum in the past. And I'm not an active member (sorry), so it might be a while before I see that I got a message.