[HECnet] Tops-20 Terminal Buffers?

[Paul Koning]

> On Nov 15, 2021, at 9:08 AM, Paul Koning <paulkoning at comcast.net> wrote:
> 
> 
> 
>> On Nov 14, 2021, at 7:27 PM, Thomas DeBellis <tommytimesharing at gmail.com> wrote:
>> 
>> ...
>> I did a transfer of the same file to an iMac and was very surprised to find that I got 4,000 byte packet size and a transfer rate 151.78 KBps.  That's right, using the NI resulted in a speed increase of 17%.  I instrumented Kermit to report the allocated monitor buffers by line type and got the table below from various sign ons, viz:
>> 
>>  TTY line Type:   FE   PTY  NRT  TVT  CTM
>>  Input Buffers:    1    1    1    1    1
>>  Output Buffers:   2    1    2    4    2
>> 
>> The abbreviations are as follows:
>> ...
>> 	• CTM, DECnet CTERM (I forget what CTERM abbreviates to)
> 
> "Network Command Terminal Specification" says the protocol spec.

Background: the original concept, which as far as I know did not work out in reality, is that there would be several network terminal protocols for several different purposes.  In particular, an editing terminal spec where the editing operations would be offloaded onto the remote system (somewhat like a VT71?).  This is the reason for the layering, with a "Foundation" layer that contains the services common to all those terminal types, and the individual mode specs for the specific cases.

In the end, only the command terminal -- roughly speaking, a line oriented interface with the rubout handling offloaded -- was specified and implemented.  The result is a split that doesn't make much sense to the observer without that history.

	paul