Tymnet circuits carries 8 bit characters thru the net on a path fixed for a login session. There were several additional signals that travelled thru over the path mostly in their turn without queue jumping. They were mostly called ‘balls’ and identified by color.
Tymnet was originally designed to drive ‘start-stop’ dumb ASCII terminals which had no logic in themselves. The 110 b/sec model 33 Teletype was the first target. ‘TD’ (terminal driver), referred to below, is the Tymnet component that stood between the Tymnet circuit and the dial-up phone line over which the ASCII terminals accessed Tymnet.
A paper by Laroy with real content!
Here is some PDP-10 assembler code dealing with Tymnet logic. It seems to be the “TYMBASE interface handler” that Sumex, an early Tymnet customer, used to adapt their host to Tymnet. I do not recall that they asked for or received any code from Tymshare.
Here we learn of “Black Ball, Glass Ball, Gray Ball, Green Ball, Orange Ball, Red Ball” in some unidentified glossary.