BKMSUNCM.RVW 930923 Sybex Computer Books 2021 Challenger Drive Alameda, CA 94501 USA 510-523-8233 800-227-2346 Fax: 510-523-2373 or Firefly Books 250 Sparks Avenue Willowdale, Ontario M2H 2S4 416-499-8412 Fax: 416-499-8313 "Mastering UNIX Serial Communications", Gofton, 1991, U$26.95/C$34.95 A title like "Mastering UNIX Serial Communications" indicates a pretty major undertaking. It is a bit of a surprise, then, to note the "Beginning / Intermediate" audience indicator on the back cover. The introduction does not state the intended audience. The book blurb suggests a range from beginning users wanting help with mail to C programmers doing development under UNIX. Quite a spread. Part one of the book is a broadly-based, but very quick overview of serial data communications concepts. Chapters one to seven discuss hardware interfacing, character transmission, and communications, parameters, handshaking and buffers, modems, phone and network services, terminals and file transfer. The material is physically well laid out with large headings and lots of white space. *Lots* of white space. Pay attention as you go through because the material is very brief. For the technically competent the lack of verbiage will possibly be quite welcome. Novice users will likely welcome it as well, since it is quite easy to refer to a specific item. The material is uneven in places. In chapter one, for example, numerous diagrams help to explain the use of the different "pin assignments" on the RS- 232 standard connectors and cables. Extra information is contained in Appendix A, and this is referred to in the text. However, the null modem cabling diagram appears to be a "straight through" connector: you have to note the pin numbering carefully to see what is intended. Some standard diagrams are given for DB25, DB9 (IBMPC-AT) and Macintosh connectors. However, the Mac diagram does *not* use the standard Mac eight-pin connector, and uses non-standard terms for the pin assignments. Again, in chapter four, Gofton talks of PAM (phase amplitude modulation) and QAM (quadrature amplitude modulation) without defining or giving any background for either, and without stating that they are two forms of the same thing, phase shift amplitude keying (PSAK). He also defines trellis encoding as a form of error detection and recovery, apparently unaware that it, too, is a form of PSAK. Gofton's definition of "full duplex" is also somewhat idiosyncratic, on page 48 asserting that it means file transfers can be taking place in both directions simultaneously. While this is technically possible, few software packages support it. Duplex is discussed more accurately on page 86. Part two is for users of UNIX systems and the basic communications utilities. Users of SCO UNIX and XENIX systems actually, and the HoneyDanBer version of uucp. The material is quite basic, but users would be wise to check out the documentation on their own system for any discrepancies. These should be relatively minor. Chapters eight to eleven give brief introductions to UNIX communications concepts, mail, uucp (for transferring files) and cu (for using or logging on to remote machines). Part three is addressed to UNIX system administrators. Ports, drivers, and the basics of administration of communications are discussed. This section should give enough information for a new sysadmin to get some basic communications going, but only just. Still, the UNIX man entries should provide the extra information needed to go further. (I note that sendmail is nowhere mentioned.) Also, again be aware of the version specific nature of this material. You may not find some of the programs mentioned in your version of UNIX; check with your vendor for the relevant alternates. Part four is addressed at the C programmer. Once again, the material is very basic, and only gives an introduction to the subject. The book concludes with three appendices. The hardware wiring diagrams were mentioned earlier, and there are also descriptions of the Xmodem and Kermit file transfer protocols. It would be difficult to say that this book allows you to "master" UNIX serial communications. It does, however, provide a single source to at least introduce you to most of the necessary topics. The bibliography contains some very decent references to extend your study into different areas. copyright Robert M. Slade, 1993 BKMSUNCM.RVW 930923 ====================== DECUS Canada Communications, Desktop, Education and Security group newsletters Editor and/or reviewer ROBERTS@decus.ca, RSlade@sfu.ca, Rob Slade at 1:153/733 Author "Robert Slade's Guide to Computer Viruses" (Oct. '94) Springer-Verlag