newbie building a scratch-built computer

Thanks for your advice, Tony. To address question #1, I'm honestly not too sure. I figure ha wih the early micros, there is documentation, where as something completely homebrew, there is little, if any. What I need to find is a good resource for electronic circuit design. I have a book called "How to Build Your Own Working Microcomputer" that I bought for under a dollar at a thrift store. I still need to finish it, but it doesn't seem to be much help in that respect.

As for your second question, I would find it to be really fascinating to build a computer out of TTL, but again, I need some kind of resource to guide me through it. All my knowledge on electronic circuitry is very basic right now. My father, an electrical engineer, tells be that he couldn't even do it after six years of college(although, he graduated 20 years ago), so I'm not very hopeful that I could. Third, commercial software would be nice, but I don't need it. I would very much like to learn machine code. I figure that when I start college interviews in a year going toward something in the technology field, I'd like to have as much pre-knowledge of computer science as I can. I figure that there's no better way than to build and program a computer. It will take me a long time, but it would be worth it.