[ih] ARPA initial IMP-IMP line speed

[Mike Padlipsky]

At 05:30 AM 2/22/2004, Noel Chiappa wrote:
>(I have this
>vague memory that they were specially conditioned)

well, i have a clear memory that we called 'em 'leased lines', but since i 
never did 'do' hardware i had no idea how they were specially conditioned, 
tho that they were such was clearly implied.  indeed, i strongly suspect 
that even the dial-up lines to multics, for those lucky enough to have 
access from home, had to be specially conditioned in some fashion in those 
times -- and weren't anywhere near 50kb/s.  [memory does serve a fault as 
to whether The Phone Company still had to be argued with, and paid thru the 
nose, for any sort of modem by then, but i wouldn't be at all surprised if 
it were still the case.] [where then = '69 thru, say, '72 or '73 ... or for 
all i know '74 or later.]

presumably, somebody who did 'do' hardware at the time will notice that 
something non-spammish is happening on [ih] again and will set us all 
straight on just what TPC did to the lines to make 'em carry that many 
bits, but since i do remember how pleased we were long about '72 when we 
were able to get rates of some 40 kb/s on ftp's going between a couple of 
multicses one hop away from each other, at least i can make it unanimous 
that 50kb/s lines were in play.   for the 'main' hosts, anyway; according 
to another fairly clear memory, it wasn't too long before some hosts [well, 
ok, some hosts' imps] were attached over slower lines, maybe as slow as 9.6 
in at least one case, whether for economic reasons or because of local 
unavailability of leasable lines suitable for the necessary conditioning 
... or whatever.


cheers, map

[whose shoulder problems caused him to break down some time ago and create 
a 'signature' file to apologize for the lack of his formerly customary 
e-volubility -- and who's been employing shiftless typing for a long time 
now to spare his wristsnfingers, in case you didn't know ... and who's 
further broken down and done http://www.lafn.org/~ba213/mapstuff.html , 
rather grudgingly]