The mid 70's were the time of the single board computer (Altair, Imsai, etc.) For about $1000, you could buy a box (or, most likely, a kit to be assembled) that would run exotic peripherals such as TV-typewriters, teletypes and even music and speech synthesizers--which all had to be bought separately. I never really got involved with these machines, except to think about how they could be applied to some of my other activities (radio, music, and model railroad related stuff, mostly)
My first run-in with anything resembling the "personal computers" of today was in 1979, when I was in a Radio Shack and the salespeople there were demonstrating something called a "TRS-80". (I had seen someone use an Apple in 1978, and around that time, one of my classmates had a Commodore PET. But this was really my first hands on experience with a "real computer").