[Oli] owns a 40-year-old IBM PC 5150 as well as the matching IBM 5151 monitor, so it was a simple matter to implement the effect in 8088 assembler to create falling sequences of characters.

which were offered pre-assembled with a monitor and keyboard. The IBM PC, however, wasn't released for another four years in 1981. The "1977 Trinity" phrase was purportedly coined and popularized ...