I worked all summer and was able to buy a TRS 80. I could not afford the cassette storage so I'd just type my programs in line by line to run them each time. They were pretty simple.

A snake like line drawer that crashed when it hit the screen edge, stuff like that. I was 12 or 13 and didn't have any mentors but I did know some BASIC from a school program. Really loved that machine.

I never tried ASM on it. Interestingly, the TRS-80 CoCo did not have a Z80, it had a 6809E @ 0.895 / 1.79 MHz. Mine had been upgraded to 64KB of RAM.