Have you ever noticed the mysterious single‐ and double‐dot entries that appear at the top of every DIR listing outside of your root directory? These are not files, nor are they named subdirectories of the kind you create yourself. Rather, they are special ways used by DOS to refer to the current' subdirectory (single dot) and the “parent” or next‐level‐up subdirectory (double dot).

Presents the XREF macro which demonstrates the use of programming variables with advanced WordPerfect macros to generate a cross‐referencing subject thesaurus. Considers the XREF macro procedure, structure, input file format and output file, including an example to show how re‐running the macro generates an updated subject thesaurus.

Discusses the booting up process of IBM‐PCs. Considers the function of IO.SYS or IBMBIO.COM in initializing hardware and loading MS‐DOS, and the MS‐DOS file processes that lead to the loading of COMMAND.COM, and the subsequent AUTOEXEC.BAT file search. Suggests ways of altering the COMMAND.COM program to change commands or limit/expand user capability.

If you use a Wyse PC (M310 Workstation) you have a useful, and potentially dangerous, command available on your system: the LOCK command. LOCK allows the system user to secure the PC from unauthorized use even if the power has been disconnected and reconnected. To use the command, assign a four‐digit (numeric) combination to the system and execute LOCK at the DOS prompt. To unlock, execute UNLOCK with the four‐digit combination as a parameter. If you have Wyse PCs in areas where unauthorized use is likely (e.g., OPAC terminals) this facility can be quite useful.

Like many regular PC users, I've developed a number of small batch files that automate various DOS processes. Many of these have appeared in this space over the years, but for the benefit of new readers I'd like to bring them all together. DOS‐tips veterans will find a few new ones in here, too—so let's get to 'em!

Oftentimes, a batch file will use the BASIC interpreter to run a BASIC program as part of its operation. Typically, the BASIC program will do some task that's difficult or impossible to do with just DOS commands like COPY and TYPE. Perhaps it conducts a dialog with the user to establish desired parameters before running an applications program. Or it may draw a fancy menu as part of a “DOS shell” system for users. Here's part of a batch file where a BASIC program is used to print out the current date in some special format:

Our method for increasing the speed of batch file execution, is based on Paul Carnahan's article in OCLC Micro, June 1988, pp. 23–24 and 28. It also includes several other techniques that I've used in our batch files.

Many of us have used speadsheets like Lotus 1–2–3 to do statistical analyses, often using data collected from various sources. For example, to manage book approval plans, subject specialists at our library tabulate the approved, rejected, and firm orders, as well as keep track of encumbrances against the budget. Our collection development officer then collects the data from the subject specialists for analysis.

Even with the advent of artificial intelligence, windowing software, and user‐friendly pop‐up menus, most microcomputer users are eventually confronted with…(theme from Jaws) …hexadecimal codes. These creatures (also known as hex codes) are often found in connection with printer and communications control and screen display characters. What are hex codes and what are they good for?

Libraries circulating software should take a few extra steps to protect the software (and users) from “pranksters.” For example, a patron might place a trojan horse program [see p. 3] on the disk that would destroy a subsequent user's data. Such a subverted [perverted?] program can be timed to “go off” only after a certain date or under certain conditions, making it difficult or impossible to determine who created the program. Avoid this by keeping archive copies of each disk and recopying the circulating disk every time it's returned, replacing any potentially altered programs with the original(s). Also check the disk's directory and delete any extra files added by patrons. [Reformatting and recopying would be safer since that would obliterate any subdirectories you might forget to look in.]