The TI-92 line rand(2) produces 1 or 2 with equal probability. You can think of this as simulating a flip of a fair coin with 1 representing tails and 2 representing heads. The screen below shows seven computer-simulated coin flips.
If we subtract 1 then 0 represents tails and 1 represents heads as shown in the screen below.
The screen below simulates 1,000 flips of a fair coin and counts the number of heads.
You may want to look at the TI-92 help modules below.