Or you needed an expansion box, with a floppy drive, in which case you could do "SAVE DSK1,PROGNAME" to save to "PROGNAME" on the first disk. I didn't have an expansion box.
Neither would have come with the base computer.
My earliest memory of anything computer programming is from the early 80s, when a snow day had the two neighbor kids, whose parents were teachers in another district, over to our house with their TI-99/4a. The oldest showed me the entry and running of the sample program Mr. Bojangles. I was enthralled.
A few years later I had one of my own, though at that point it was very long in the tooth. But I still learned its limits, playing (yes) Hunt the Wumpus, Tombstone City, and others, programming, and doing things like composing the Jeopardy! theme song in BASIC.
I have one of these again, with the stuff I had as a kid, and more (like the voice synth) and it's so limited even for the era, but still iconic.