Actually, I think I may now have CISS running on the MP830.
I had to take the entire printer carriage out, remove the terminals and circuit boards that interface with the chips on the ink carts, clean all the ink out of the terminals and this small circuit board, then put the whole carriage & printer back together again. Now it's recognizing the chips on the OEM (and CISS) carts again.
This is a longstanding problem though that has just gotten worse until I finally just went in and fixed it. What a waste of my time.
I think I may just remove the chips from the carts and solder them onto this board, then seal the board or move it somewhere where it can be cleaned more easily & I don't have to take the entire printer apart to fix their shitty design problem.
What a pain in the ass. Canon designs chips on their ink cassettes ostensibly to keep people using inks that may screw up their printers causing problems with their warranty, yet the least reliable aspect of the Canon printer is the actual circuitry that reads their god forsaken chips. I can tolerate if the have a complex and necessary part like a print head that malfunctions. But when they add something to the printer to frustrate me from using it, like a chipped cart system, and then that is designed horribly so that it's the first thing that breaks (just google how many people have Canon printers that have problems recognizing OEM carts), and that's about enough to make me want to run homicidal.
Oh well, I'll just stick with this old beast on CISS until it breaks again, then throw it out.
Thank you everyone for all your help - even if you didn't know it, I was reading your posts.