We know from the Datapoint 3300 Maintenance manual the characters were formed on a 5x7 grid, and on page 2-55 we have an "A". But is it known what the rest of the characters looked like? According to the Instructions manual, the 3300 had old ASCII style ↑ and ← instead of ^ and _, which doesn't match the TI datasheets.
EDIT: I'm adding a picture of the character generator ROM from the schematics.