In January 1981 the design was ready (documented in IEN168) and coding proceeded. In parallel, several loose ends in the TCP/IP specifications were tied in (for example, ICMP replaced GGP as the control message protocol) and these specification changes were back integrated into the code base. In November 1981 a beta distribution tape that overlaid on 4.1BSD was ready. The network API was very similar to that of the earlier NCP Unix (see SRI_NOSC). With DARPA funding, the code was further developed and maintained into the early 90's.
Next to networking extensions to the kernel, the beta distribution tape contains several user programs such as clients and servers for Telnet and FTP. It also contains a mail system based on a precursor to SMTP, called MTP. MTP shows the transition of mail from a feature of FTP to an independent protocol.
Separately, DARPA contracted in 1981 with Berkeley's CSRG to develop 4.2BSD and to integrate this reference implementation with it. As such, it became the starting point for 4.1a BSD. This beta distribution tape comes from the CSRG archives.
| File | Size | Date |
|---|---|---|
| BBNSYS | dir | |
| LABEL | 150 | 1992-12-01 |
| bbnnet | dir | |
| bbnnet-oct82 | dir | |
| conf | dir | |
| dev | dir | |
| doc | dir | |
| etc | dir | |
| floppy | dir | |
| h | dir | |
| history | 5383 | 1981-09-04 |
| include | dir | |
| lib | dir | |
| src | dir | |
| stand | dir | |
| sys | dir |