I meant to say when TCP/IP was publicly available. I think ARPANET was only available to the military.
Jon Perryman. >________________________________ > From: Anne & Lynn Wheeler <l...@garlic.com> >To: IBM-MAIN@LISTSERV.UA.EDU >Sent: Tuesday, November 5, 2013 2:14 PM >Subject: Re: z/OS is antique WAS: Aging Sysprogs = Aging Farmers > > >jperr...@pacbell.net (Jon Perryman) writes: >> * UNIX: TCP/IP was not publicly available until the 70's. Prior to >> that, simple communications were available. >> >> * z/OS: SNA existed long before TCP/IP was available. SNA was a >> robust, reliable and secure communications methodology. Once TCP was >> became available, we had the same situation as Betamax versus VHS. TCP >> won. > >arpanet was host-to-host with IMPs from late 60s ... and in many ways >similar to SNA (but well before SNA). big problem was that it wouldn't >support large distributed ... and frequently autonomous, decentralized >infrastructure ... and so start was made on internetworking protocol. > >the great change over of arpanet to internetworking (tcp/ip) protocol >came 1Jan1983. at the time there was approx. 100 IMP network nodes with >around 255 connected hosts. > > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN