Curtis Spangler, N6ECT, has kindly created an archive of documents and photos from amateur radio packet networking history. The Pacific Packet Radio Society was a small group of hams in the San Francisco Bay Area, led by Hank Magnuski, KA6M, in the 1980s. Hank's KA8M-1 repeater talked half duplex at 1200 bits/sec with VADCG Terminal Node Controllers throughout the Bay Area. A good chunk of the history is here, including how Hank originally requested and received the 44net IP address allocation:
In particular, in this page, Hank wrote on 1981-06-10 to Paul Rinaldo, W4RI, thanking him for information about the INTERNET protocols, and reported:
http://www.pprs.org/bulletin/pages/page003.html
"In looking over this document the application of the standard is fairly straightforward except for one area, and that concerns addressing. A four byte source or destination address is specified, and that does not meet our needs. The first byte of this four byte field represents a network, and about 40 of the possible 256 combinations are already assigned. I attempted to contact the author of the document to see if a number could be assigned to an amateur radio experimental network, or to see if there already was a number for personal computing networks, but John [sic] Postel was out of town, and I didn't get an answer to my question. It seems clear that 256 networks is somewhat limiting, and that some future revision of the standard will have to expand this field."
(As we now know, figuring out how to allocate network addresses, and route packets among them, is not as simple as it seemed back then!)
Page 13 reports, in a 1981-12-06 page of notes about how to build packet repeaters and networks:
http://www.pprs.org/bulletin/pages/page013.jpg
"Direct connect stations using IP protocol can use "NET 00 00 00" as the network node address. NET is decimal 44."
John Gilmore, W0GNU