For Dissecting DOS, I recommend eBay, but it is available on Amazon: https://www.amazon.com/Dissecting-DOS-Code-Level-Operating-System/dp/020162687X/ref=sr_1_1

For Dissecting DOS, I recommend eBay, but it is available on Amazon: https://www.amazon.com/Dissecting-DOS-Code-Level-Operating-System/dp/020162687X/ref=sr_1_1?crid=1BGSDZ592N8NC&keywords=dissecting+dos&qid=1671836287&s=books&sprefix=dissecting+dos%2Cstripbooks%2C93&sr=1-1 https://www.amazon.com/Dissecting-DOS-Code-Level-Operating-S... The original companion floppy for that is available on archive.org: https://archive.org/details/dissecting-dos-companion-floppy-disk https://archive.org/details/dissecting-dos-companion-floppy-... Understanding Microprocessors is a small book, and currently unavailable anywhere I've seen except for eBay, but it's also normally quite inexpensive.