You're assuming he's running Kickstart 3.1. 
I'm assuming he's running at least 2.04, and since he said he has an A500+, all of those came with 2.04 unless they were retroactively replaced with a 1.3 ROM.
Granted I haven't used 2.04 in 20-something years, but AFAIR it has some kind of an early startup menu.
