Back in 1986 I installed my first PC network, which used an IBM XT as the server and IBM PCs as workstations. Hardware maintenance and upgrades consisted of calling my IBM rep and getting a new part, which came with full instructions. When one company supplied the hardware and most of the software, there weren't a lot of choices. Then along came Compaq and things changed. Things changed fairly rapidly.There were lots of new companies around wanting to sell me disk drives and video cards, RAM chips and network cards. Disk drives, which previously all had the "ST-506" interface now had something new, called "scuzzy" (OK, so it was Small Computer Systems Interface - SCSI). For a software and\u00a0operating system\u00a0guy like myself, it was a deep, dark forest of hardware full of uncertainty and dread. I needed a guidebook.In 1988, Scott Mueller brought forth that guidebook, "Upgrading and Repairing PCs." I bought a copy from my local computer parts store and it became my constant companion. In 1991, when I left the company I was with, the book stayed. Its binding was broken and the pages were very dog-eared and covered with cryptic notes. But it had been a faithful companion. One of the first things I did at my new company was to acquire a more recent edition of "the book" (as in, "I need to make a cable for this modem, have you seen the book?").That first edition was a relatively slim volume. There weren't that many different products and technologies to talk about. But last week when the postman delivered my latest copy, he did glare at me and mention something about "back strain". (He's not a young man any more, but then so few of us are.). The "15th Anniversary Edition" runs to 1,600 pages - not something to carry around in your back pocket. It's not the 15th edition, by the way - there isn't a new one each year. It's just a new edition published on the 15th anniversary of the first one. To save your strength, "the book" is now part of a series - the "Upgrading and Repairing" (U&R) series. The new books are smaller and more portable: there's "U&R Laptops," "U&R Servers" and "U&R Networks".The 15th edition U&R PCs covers every subsystem in your PC and all the parts of each. It tells you what the standards involved consist of (e.g., SCSI, SCSI-2, Ultrawide SCSI, etc.), what the interface is like (and what pinouts a cable will need), where to find drivers and how to connect it all together. The included DVD-ROM has huge amounts of readily searched information and data as well as over two hours of "how to do it" video.If you ever have to take the cover off of a PC, you need a reference like "Upgrading and Repairing PCs." Check it out today.