I used to &quot;collect&quot; file transfer utilities back in my BBS days. When I found source code on some old floppies, I decided to publish them on GitHub for future generations:<p>* <a href="https:&#x2F;&#x2F;github.com&#x2F;cpeterso&#x2F;jmodem" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;cpeterso&#x2F;jmodem</a> (1990, Richard B. Johnson)<p>* <a href="https:&#x2F;&#x2F;github.com&#x2F;cpeterso&#x2F;sealink" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;cpeterso&#x2F;sealink</a> (1987, Thom Henderson, System Enhancement Associates)<p>* <a href="https:&#x2F;&#x2F;github.com&#x2F;cpeterso&#x2F;wxmodem" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;cpeterso&#x2F;wxmodem</a> (1986, Peter Boswell)<p>* <a href="https:&#x2F;&#x2F;github.com&#x2F;cpeterso&#x2F;zmax" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;cpeterso&#x2F;zmax</a> (1990, Mike Bryeans, Micro TECH Systems)<p>Other utilities for which I have MS-DOS exes but not source code include: BMODEM, BiMODEM, CMODEM, Leech, Lynx, Puma, TMODEM, YMODEM, and others. Leech was compatible with X&#x2F;Y&#x2F;ZMODEM but it would fake a transfer abort after the last byte was downloaded so the BBS would not count the file download against your quota. &gt;:)