Hacking in those days was a rather strightforward affair.
Walk into RS store.
Type
10 print "some profanity"
20 goto 10
Leave store before RS dude sees you.
Walk into RS store.
Type
10 print "some profanity"
20 goto 10
Leave store before RS dude sees you.
10 PRINT "SOME PROFANITY ";
20 GOTO 10
Also, of course computers of that day didn't use lower case (it seems that was an add-on for the TRS-80) quite as often as we do today. :)
And yes, I checked the BASIC manual for the TRS-80: http://www.trs-80.com/trs80-info-level2.htm#IO to make sure this was supported, I never had a TRS-80.
Since the screen was 40 characters wide (at least on the Apple ][ it was), the print would happen 3 times and then the next one would wrap around and be offset by 1 character on the next line.
This had the effect of making the words appear to smoothly scroll horizontally across the screen as the text rolled vertically.
I've been a software developer professionally since not long after that.