Technical Cofounder - How much equity do I ask for?

Reddit is generally lower quality than HN, but this is a pretty good discussion!

I think the big mistake was not starting with some form of agreement or understanding on what the split would be. But what's done is done, and it's interesting to negotiation from that postponed position.

Maybe I'm ruthless, but in my mind the technical cofounder would own all the code he's written so far. And he should use that as a bargaining chip-- I'm assuming it would be easy to keep the source code from the business cofounder, and even if he couldn't the business cofounder can't do much without the first dev.