Only Fools and Horses (1981) : 5x5

Rodney gets a grant from the local college to make a film, but first he must come up with a viable screenplay. Del gets him a secondhand typewriter, and also suggests a storyline of 'A Rhino Loose in the City'. To make matters worse, the director, Mickey Pearce, fed up with waiting for Rodney to write the story, starts making porn films, only for Rodney to end up starring in one.