To solve the problem, I put in a SATA card. That works well, for a bit. Then, it's all funka-tron again.
Damned computer. I don't want to pay for a new motherboard.
I could go through the warranty and get a new motherboard. Or, I can save two hours of my time and just buy a different one. Right now, I value my time more than I value my money.
I've been gaming on my MacBook lately. Partly, this is because my main computer is down, but mostly this is because I can sit upstairs and bed and see my wife, then go to bed at a reasonable hour. Unfortunately, gaming via Wine heats up my laptop like nobody's business. My eventual solution was to put a cookie sheet on my lap, which then acts like a heat sink. It worked far better than I hoped. Even better, the arrangement uses no power.