// About this item’s rarity and value: This is a genuinely rare 1981 publication by On-Line Systems (later Sierra On-Line), documenting the Lisa assembler for Apple II. Physical copies are very hard to find, especially complete and in good condition. While digital scans exist, original print editions are sought-after by collectors of vintage computing gear. According to vintage tech auction platforms like WorthPoint, this book is considered rare and collectible, with historical significance in early Apple II software development. // A great addition to any retrocomputing collection! Rare Vintage Find – "Lisa: A Professional Assembly Language Development System for Apple Computers" (1981). By On-Line Systems (Sierra On-Line) Step back into the golden age of computing with this hard-to-find original 1981 publication, documenting Lisa – the most powerful interactive 6502 assembler ever developed for the Apple II. Published by On-Line Systems, the company that would later become the legendary Sierra On-Line, this book is a must-have for collectors, retro enthusiasts, and anyone interested in the early days of software development. Inside, you'll find: Comprehensive documentation on Lisa's capabilities Technical insights into Apple II assembly programming A genuine piece of computing history Whether you're a vintage tech collector, a retro programming hobbyist, or just love the charm of classic Apple software, this book is a rare gem that doesn't come up often. Own a piece of 1980s computing history – Lisa is calling.