I wrote a Student Information system for my midterm project back in 94 written in Clipper and runs on MS-DOS.

I demoed & explained to the panel of professors how it tracks enrollments, payments, class schedules, grades and attendance of each and every student. Has user authentication, auditing and reporting functionalities.
It has a lite version also written in Clipper that can be installed on a Professor's laptop so that he/she can update records even at home, and would be able to sync with the db at school via a BBS. Telix for DOS (self-taught) was my choice for the BBS as it was shareware, has built-in Zmodem support and comes with it's own programming language called SALT (Script Application Language for Telix) that can be used for automating tasks. The lite version of my project would dump the updates on an ASCII file, compress the file using PKZIP, use the laptop's modem to dial-up the number to the school's BBS and send the file across using Zmodem protocol.
The main version would then download the file(s) from the BBS and proceed to do a sync.

After the doing the demo and answering all their questions the panel asked me to wait outside the room, called me back in after 15mins and told me that I don't have to attend that class for the remainder of the term. The happiness as the my classmates outside of the room gawked at me felt like King Midas himself gave my balls his golden touch.

Then in 97, 2yrs after I graduated, I accompanied my cousins to a different campus of the same school for their enrollment and right there on the bottom of the screen were my initials on a very very familiar UI! They actually used, and were still using, my school project. Needless to say my cousins didn't believe that it was written by me.

We are having a history lesson updating a system that was built around 1985.

It's a custom built sales and customer tracker, programmed in Clipper, which is a superset of xBase, that is a language that appears to be data orientated. DosBox and Dosemu have both failed to run it, the programs loads and indexes just fine, but when it gets to the program dashboard it shows the options and doesn't seem to accept any input, though it appears to be running as the time updates (any ideas?)

Tried compiling the source using harbour, compilation fails, something about "time" having too many arguments and other obscure errors. Urgh.

Dbf files are easily converted and opened but really we want to view the working program to see the relations so we can translate the data models.

It's both fascinating and infuriating at the same time.