The “Radio Shack TRS-80 Expansion Interface: Operator's Manual” serves as an essential guide for enthusiasts and operators of the iconic TRS-80 microcomputer, often revered as one of the pioneers of personal computing. The manual presents a detailed exploration of the expansion interface's functionalities, providing users with systematic instructions, practical tips, and troubleshooting methods. Written in a straightforward, technical style, the text reflects the nascent era of computing in which clarity and accessibility were paramount for users navigating new technology. Contextually, this manual fits within the broader tapestry of late 1970s and early 1980s computing literature, marking a period of rapid technological advancement and increasing user engagement with computers. The authorship of this manual remains anonymous, reflecting a common practice among instructional manuals of this era, where the focus is on the utility and educational value rather than individual identity. The commitment to empowering users through clear instructions mirrors the ethos of early computer pioneers and educators who sought to democratize access to technology, sharing their knowledge with a growing community of hobbyists and learners eager to explore the capabilities of their machines. This manual is indispensable for anyone involved with the TRS-80, whether they are seasoned operators or curious newcomers. By offering insights into the practical application of the expansion interface, the manual serves as both a comprehensive educational tool and a nostalgic journey into the roots of personal computing. Embrace the challenge and potential of your equipment with this indispensable resource.