Lance Leventhal, Author of Assembly Language Books   Lance Leventhal wrote 25 computer books, spanning 1978 through 1992. His books include  6502 Assembly Language Programming, 6502 Assembly Language Subroutines, Z80 Assembly Language Programming, Z80 Assembly Language Subroutines, 6800 Assembly Language Programming, 6809 Assembly Language Programming, and Why Do You Need a Personal Computer?   This interview took place on August 25, 2017.   "Be careful about avoiding sidetracks. Don't go down them. There's always things you'd like to say and things you'd like to talk about. But they're not central to your topic and you've got to be brutal about not saying them."   Scans of many of Lance's books at Internet Archive