A Commodore PET 2001 with a tiny "Chiclet" keyboard, 8K of RAM and Microsoft BASIC. I wrote code on that thing from 6:00 in the morning until 9:00 at night just breaking for classes. The school gave me a key to an unused classroom and I would carry the computer from the programming teacher's room to "my" room and back. I taught myself BASIC, 6502 Assembly language (no assembler, so I guess it was really machine code), boolean logic and most of the most of the programming concepts I use to this day.
I was blessed because my teacher didn't know BASIC and refused to learn it, "I'm retiring in a year and I'm not going to spend time on that." He'd been the FORTRAN teacher for years and so that's what he taught even though we didn't have a computer we could use it on. We helped each other with BASIC, but I was the only one in the class who was completely hooked.
I got my first programming job about 2 months after I started the class. There I also programmed on Commodore PETs along with Apple ][s and Exidy Sorcerers.
Before I took that high school programming class I had no idea what I wanted to do with my life. Afterwards there was no question.