Age 17 in 1977, a IBM 1130, which I'm sure was pretty much the standard configuration including a hard disk: https://en.wikipedia.org/wiki/IBM_1130 We students had hands on access since by then the model had been out for a dozen year and real users were using faster machines (it was leased by the local college for exactly this purpose, they had a 370/115 for the main computer), we loaded our punched cards (FORTRAN), broke it out of a loop if needed, etc.