Qmodem source code released by the author's son...
https://github.com/AaronFriel/qmodem-4.51
The source code release of QModem 4.51, an MS-DOS telecommunications
program authored by John Friel III (1960-2024). This source snapshot
reflects the state of QModem "Test-Drive" edition, version 4.51, as it
existed in early 1992. The release is presented in the hope it may prove valuable as a historical artifact, for telecommunications enthusiasts, retrocomputing hobbyists, or anyone interested in the inner workings of
a classic DOS comms package.
--- MultiMail/Win v0.52
* Origin: realitycheckBBS.org -- information is power. (21:4/122)