READBTOC.TXT 12/07/1999 READBtoC.TXT for UPGRADING Epi Info 6.04b Year 2000 Compatibility and Minor Other Improvements The file 4BUPDATE.EXE contains updates to the 01/13/97 release of Epi Info, Version 6.04b. These are the components of Version 6.04c that provide Year 2000 date compatibility and several minor bug fixes. DISCLAIMER Although we feel that these files are ready for release, experience has shown that distribution to a variety of users in different parts of the world often discloses minor problems that can be fixed before the final release of Version 6.04c as a unit, rather than as a series of update files. BACK UP YOUR EPI 6.04b FILES FIRST We have made every effort to produce software of high quality, but still recommend keeping a backup copy of your Epi Info 6.04b system, either as the original installation disks or on your hard disk. If, for any reason, you have problems with the 4BUPDATE, please let us know, and be prepared to reinstall the previous version. Of course, if you do not need to use 4-digit years in your date fields, there may not be a reason to install the UPDATE, and you may wish to wait until 6.04c is released. The 4BUPDATE does, however, include all the functions that will be included in 6.04c. INSTALLATION To install this upgrade, first be sure that Epi Info, Version 6.04b, is currently in your computer, and then place 4BUPDATE.EXE (a self-extracting compressed file) in your EPI6 directory and type 4BUPDATE. (Alternatively, you can log in to the EPI6 directory with a command such as CD \EPI6, and then run the update file from elsewhere--for example, by typing A:\4BUPDATE). You will be asked, for each new file, if you wish to overwrite the existing file. WHAT'S NEW IN THIS UPDATE? Year 2000 Compatibility *Year 2000 (4-digit year) date capability has been added to ENTER, ANALYSIS, IMPORT, EXPORT, MERGE, and REC2QES. *A utility called YYTOYYYY has been added to create a new (empty) data file containing dates with four-digit years from an existing data file *The REVISE option in MERGE will add the current century to values in date fields if necessary, after the format has been changed from to , or the equivalent European date format *The REC2QES program has been improved Bug Fixes *ANALYSIS now runs the CONFIG.EPI file (if any) before files run from the DOS command line *WRITE RECFILE in ANALYSIS now writes defined variables with color settings compatible with the rest of the questionnaire *Problems with random number generation in EPINUT and EPITABLE have been corrected *EPINUT, EPITABLE, and DOMEAS failed with a Runtime 200 error when run on Pentium II machines; this has been fixed. *CHECK now allows 4-digit years for Range (Max and Min F1/F2) entries in check file mode from the Check program. *EXPORT now properly exports 4-digit years to dBASE IV files. WHAT IS "YEAR 2000 COMPATIBILITY?" As pointed out by many experts in the past few years, serious problems can be predicted early in the year 2000 in computer systems that depend on dates having two-digit years and the assumption that the century is always "19xx." For example, malfunctions might occur in the following software operations: *Sorting a list of dates, since the year "00" would normally be sorted to come before the year "99", but 2000 should definitely not come before 1999. *Subtracting one date from another, since this could give negative numbers (duration of stay, incubation period, the interest on your credit card)! *Automatic revisions triggered by comparing dates in files (Don't panic, most operating systems already use four-digit dates.) These problems can be prevented by using four digit years in all date fields. This revision of Epi Info provides four-digit years. It is recommended that all questionnaires using dates employ the four-digit year formats, and
. Doing so will solve the "Year 2000 Problem" for files and programs created and used with this version (6.04b-to-c update) of Epi Info. For correct calculations and other date-related functions with four-digit years, you must use the 6.04b-to-c update. Previous versions allowed the creation of four-digit years, but did not always perform calculations or frequencies correctly with these fields. Using four-digit years and the new version is all you need to do to maintain year 2000 compatibility in systems built with the new software. FURTHER INFORMATION - CONVERTING EXISTING EPI INFO DOS SYSTEMS TO YEAR 2000 COMPLIANCE Detailed information on Year 2000 conversions is provided in the file called YEAR2000.TXT. This information is intended for those who: 1) Have existing data files or systems with 2-digit dates that will still be used in the year 2000 2) Do not intend to convert these systems to another system, such as EpiInfo 2000 for Microsoft Windows 95 and NT, which will be fully year-2000 compliant For new files and systems, it is only necessary to use the Epi Info 6.04 b-to-c update and be sure that all date fields contain four-digit years. Those with existing data files and systems that will be maintained as DOS Epi Info systems should consult YEAR2000.TXT for more information. OBTAINING TECHNICAL ASSISTANCE State health departments in the US should consult their CDC technical liaison for the NETSS system before upgrading a state NETSS surveillance system. Others may obtain technical assistance from the Epi Info Hotline at (404) 639-0840. The FAX number is (404) 639-0841 and e-mail address epiinfo@cdc.gov. Please report any problems with the 4BUPDATE to the Hotline promptly so that others may benefit. To obtain information, download the latest version of Epi Info, or join the Epi Info Worldwide Discussion Group (LISTSERV), consult the Epi Info web pages, starting with www.cdc.gov, and choosing "Publications, Software, & Products," then "Software," and "Epi Info" and "Epi Map." 4BUPDATE.EXE contains the following files: ----------------------------------------------------- ANALYSIS.EXE - Changes were made to support "European" SYSTEMDATE, correct assignments and calculations involving European and mixed date types, to more fully support 4-digit years (YYYY) and deal properly with dates beyond 1999, to use appropriate colors for files written with WRITE RECFILE, and to fix bugs in reading EPIINFO.CFG and in running CONFIG.EPI. NOTE: ANALYSIS.EXE now contains what was, in previous releases, stored in ANALYSIS.OVR; hence, there is no ANALYSIS.OVR contained in 4BUPDATE.EXE. ANALYSIS.HLP - A minor typo was corrected. CONFIG.EPI - CONFIG.EPI contains sample ANALYSIS commands for configuring a printer (in this case, a Hewlett Packard-compatible laser printer). The commands in CONFIG.EPI (if present) are executed when ANALYSIS is started. ENTER.EXE, ENTER.OVR, and ENTERX.EXE - Fixed a bug in validate mode when one field is blank. Added more support for 4-digit years (YYYY) and dates beyond 1999. Dates can be changed between 2-digit year format (YY) and 4-digit (YYYY) by revising the .QES file and revising the structure of the .REC file. NOTE: It is crucially important that the copy of ENTER.OVR contained in 4BUPDATE.EXE be placed in the same directory as the copy of ENTER.EXE contained in 4BUPDATE.EXE (ENTERX.EXE does not use ENTER.OVR). EPED.EXE, EPED.OVR - A 4-digit year format was added to the available formats on the QUESTIONS option. NOTE: It is crucially important that the copy of EPED.OVR contained in 4BUPDATE.EXE be placed in the same directory as the copy of EPED.EXE contained in 4BUPDATE.EXE. EPINUT.EXE - A problem in random number generation causing duplicate numbers to be generated even when "sampling without replacement" was corrected. EPINUTE.HLP - A clarification about random number generation was added. EPITABLE.EXE - A problem in random number generation causing duplicate numbers to be generated even when "sampling without replacement" was corrected. EPITENG.HLP - A clarification about random number generation was added. EPITENG.RES - An error message was corrected. EXPORT.EXE - Code for "dBase" files was changed to insure handling of YYYY Today fields. MERGE.EXE - Added support for changing between 4-digit years (YYYY) and 2-digit years (YY) when revising a file. Note that when a 2-digit year is converted to a 4-digit year, the century (the first 2 digits of the year) used is taken from the computer's date. If that is not appropriate, the date on the computer must be changed or some other means (such as an ANALYSIS "pgm") must be used to change the dates. At any rate, it would be wise to back up important data sets before converting dates, with MERGE or any other tool. MERGE.HLP - A note was added about converting from a 2-digit year to a 4-digit year. REC2QES.EXE - The program now handles 4-digit date fields. READBtoC.TXT - This file YEAR2000.TXT - A text file containing instructions for updating existing files under various conditions. YYTOYYYY.EXE - A utility that will create a new, empty data file and change date fields containing yy to yyyy