The idea that big computers and little computers were fundamentally different goes back at least as far as 1976, when I ran into Steve Jobs at Country Sun Natural Foods in Palo Alto.
Both of us being hippies, we got to talking and Steve told me he'd just started a company with a friend and explained the name: "Take a byte out of the apple, get it?"
He mentioned that they needed a 6502 disassembler, and I said that was right up my alley. I'd been programming for eight years and had done low level assembly and binary machine code on several different architectures, so this looked like a fun little project.
We didn't talk money, not that he had any, it just seemed like an interesting weekend diversion.
Steve called me a couple of days later and said, "Mike, I've been thinking about this. Your experience is all with mainframe computers. The 6502 is a microcomputer. It works on fundamentally different principles than those mainframes. There's no way you could possibly write this disassembler, so forget it."
I tried to explain that I'd gone through the 6502 reference, and it was just another instruction set with concepts similar to the others I'd worked with. Steve wouldn't have any of it: "I'm sorry, I've made up my mind. You just don't know anything about microcomputers, all you know is mainframes. Goodbye."
Naturally I said to myself, "Who is this Steve Jobs guy telling me I can't program?" So I went ahead and wrote enough of the disassembler to show that I did indeed know how to do it.
I was about to call Steve back to tell him the good news, but then I thought, "The last phone call didn't go so well. Maybe I'd better drop by his office and show him the code."
So I looked up the address for Apple Computer and found it at 770 Welch Road in Palo Alto. I walked into the building and looked around. It didn't look like a computer company, all I saw was a row of telephone switchboards - the old kind with plugs and jacks - with an operator at each one.
I asked one of the operators where Apple Computer was. She hesitated a moment and said, "Uh, this is their answering service."
Well, of course no successful business used an answering service. I turned around and walked out the door, saying to myself, "These guys are flakes. They're never going to make it."
To this day I don't know if I missed out on becoming a billionaire, or if I dodged a bullet.