I came across documentation about the popular Apple II copy program EDD 4 that experts like Anthony Martino at UltimateApple2, the creator of the “EDD 4 Plus” clone card, were not familiar with and asked me to share. That information is within three documents I scanned and linked here as PDFs. Highlights from those documents:
EDD 4 Program Information List #4-13, February 1993: download PDF
This may be one of the last EDD program lists created. It also mentions a version of EDD that doesn’t appear to have been archived – was this the last revision? “EDD disk revision 4.9L, January 1993 is the latest revision of EDD.”
EDD 4 Plus Addendum: download PDF
Back in the 1990s, users who had duplication problems could return their original cards to Utilico Microware for modification. The mystery is what that modification was. “…we can modify the card so that the accuracy of normal disk drive operations increase; but unfortunately the accuracy during the copying process will decrease from normal PLUS card ability. Use this ONLY as a last resort.”
EDD 4 Manual Corrections: download PDF
“Apple computer’s specifications say that a disk drive is suppose to run at exactly 300rpm. From our extensive testing over the years, 300rpm is a bit on the fast side. A slower drive gives less problems and errors during normal operation, and backing up disks. 298.5rpm seems to be about the best “all around” speed setting. For normal operation, we recommend that the speed of a drive should never exceed 300rpm, and 296.5rpm should be the slowest.”
