<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span>We (BBN TIP developers) had a mandate (from ARPA) to support the 2741 because:</span></div><div><span> a - it was _the_ standard Multics terminal</span></div><div><span> b - it was _a_ standard IBM terminal</span></div><div><br><span></span></div><div><span>Cheers,</span></div><div><span>Alex</span></div><div><br></div> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div dir="ltr"> <font face="Arial" size="2"> <hr size="1"> <b><span style="font-weight:bold;">From:</span></b> Bernie Cosell <bernie@fantasyfarm.com><br> <b><span style="font-weight: bold;">To:</span></b> internet-history@postel.org <br> <b><span style="font-weight: bold;">Sent:</span></b> Sunday, July 1, 2012 10:04
AM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [ih] FTP Design<br> </font> </div> <br>
On 1 Jul 2012 at 7:24, Dave Walden wrote:<br><br>> I hope Bernie can say how much he was thinking about this before our <br>> airplane flight during which he described his idea on cocktail<br>> napkins.<br><br>I can remember a bit, but as with most of that stuff back then it seemed <br>more fun and interesting than significant so I didn't pay a lot of <br>attention [sigh!]. From my work on the TIP I was already thinking a bit <br>about making telnet symmetric. What I was mostly grapping with was if <br>the protocol were symmetric it could "loop" -- if commands passed each <br>other over the net, then the responses passed each other, and those <br>kicked off other responses, etc. [one that came to mind (that I recall <br>thinking about back then) was with one end saying "I'll send echoes" and <br>the other saying "I'll echo locally". They cross, and each then responds <br>"OK you echo". Each now has gotten a change
of state [since each said <br>they weren't going to echo and now has been told to] and so each sends <br>another "OK I'll send echoes" and "I'll echo locally" and around they <br>go....<br><br>My actual goal in the sketching on the napkin on the plane flight [and I <br>remember mentioning it to Dave, sitting next to me, and waving my hands a <br>lot] was "Look: if the commands are will/wont/do/dont and the rules <br>follow <THIS> state diagram, then it can't loop and will always end up in <br>a reasonable state [just not-looping wasn't enough, of course, lest the <br>connection end up with BOTH ends thinking that the other is echoing, or <br>vice versa]. Another important idea that it handled was that it was <br>extensible: it provided for the notion that one side could ask about <br>something unknown and that'd be OK [and the negotiation would do the <br>right thing], so there could be fancy-hosts and not-so-fancy ones and <br>they could
negotiate to make as clever a connection as they could while <br>still gracefully handling hosts that could only deal with not-so-clever <br>ones.<br><br>As I mentioned in a previous thread about this, I really don't recall <br>hardly any discussion about this at the meeting [which, I admit, I only <br>vaguely recall at all]. I gather that the proposal was just accepted <br>[or, perhaps, that Dave did a lot of lobbying/arguing on my behalf that <br>I've forgotten..:o)] and my recollection was that attention almost <br>immediate turned to designing options. [one of the first I recall [did <br>it ever get implemented?] was RCTE: remote controlled transmission and <br>echoing, that was proposed by someone from Hawaii]<br><br><br>> Will Crowther BBN<br>> <br>> (Crowther was undoubtedly there because of the TIP software effort
at that<br>> time.)<br><br>right: At a design review that I still get shudders over, I proposed the <br>idea of hacking the IMP, when it moved to the 316 [which had an extra 16K <br>of memory], to run "split" -- the upper 16K running as a wholly separate <br>system [a proper host system, actually] with the imp part simulating its <br>I/O hardware. The "upper host" could be written as if it were a <br>standalone program on a 516 with the IMP [below it] simulating interrupts <br>and I/O commands and such. My recollection is that Frank was very <br>dubious that that would work, but I got the go ahead anyway.<br><br>Will worked on the original TIP code. A bit after that, Ralph Alter <br>started work on the IBM 2741 [that the right number?] code. When it all <br>kind of worked, they both went to other projects (was that when Will <br>started on the Pluribus?) and I inherited it. The NVT stuff was clearly <br>a necessity: in a
world of fullduplex, character at a time, ascii <br>terminals, we were writing code to make a half-duplex, line-at-a-time <br>EBCDIC terminal work. [and I think that after I hacked on the code <br>enough eventually it did: you could actually log into a TENEX system from <br>the 2741]. Dave probably remembers: why did we have the mandate to <br>support the 2741?<br><br> /Bernie\<br><br>-- <br>Bernie Cosell Fantasy Farm Fibers<br>mailto:<a ymailto="mailto:bernie@fantasyfarm.com" href="mailto:bernie@fantasyfarm.com">bernie@fantasyfarm.com</a> Pearisburg, VA<br> --> Too many people, too few sheep <-- <br><br><br><br><br><br> </div> </div> </div></body></html>