[vcf-midatlantic] time for me to learn assembly

Hey everyone. Trying to teach myself Apple II assembly. I have NO experience at this. All I ever learned was LOGO in elementary school and AppleSoft (Microsoft) BASIC in middle school. (I'm not counting a very small amount of LISP in college and mastery of HTML 4 which isn't programming.) Everyone said to get the book Assembly Lines. I got the PDF of the original version. Hit a glitch almost immediately. After doing CALL -151 to enter the monitor, it says to type F666G to enter the mini-assembler, and then "The prompt should change to an exclamation mark." It doesn't change to an exclamation mark. It just goes back to the asterisk. What's happening? Same behavior in LinApple (Linux Apple II emulator) as on my Platinum.