KeyDex was an information retrieval system for MS-DOS with a text-mode UI and menu system.
This was the first commercial product of my career. Back in 1987, I spent countless hours writing this application in Modula-2. Because of the limitations of PC hardware, I had to put lots of effort in fine-tuning and optimizing every single bit of code for space and performance.
It was quite a success at its time, considering that the Internet wasn't commonplace back then and the software had to be marketed through computer magazine ads, BBS announcements and direct mailing. As far as I'm aware of, it was among the first commercially available DOS applications to implement a user-friendly "Rolodex-type" database with full-screen editing, blazing fast keyword and full-text search features (even for data stored on floppy disks), and screen templates.
I distributed KeyDex on 5.25" floppies. The application included an extensive help system, which was tied-in via a third-party help compiler (unfortunately, I don't remember the name of that product anymore).
Minimum system requirements at the time were: 256K RAM, MS-DOS 2.0 or greater. I wrote the source code for the Logitech Modula-2/86 compiler, version 3.00.
I'm publishing my efforts of past times under the GPLv3 license for the enjoyment and education of the generations after me. Hopefully I will eventually find the time to port this code to a current environment, such as Linux with ncurses. Because of its efficient design for small-volume storage, I see potential in extending this into an encrypted data manager on embedded devices.
Guido Hoss, April 2016