Some HP 3000 and HP 1000 computers use a form of handshaking called Enq/Ack
(Enquire/Acknowledge) to prevent the terminal (or in this case, the Host Integrator)
from falling too far behind the host system and losing data.
With Enq/Ack pacing, the host system sends 80 characters followed by an ASCII
Enq character and stops transmitting. When the Host Integrator has processed
all of the characters preceding the Enq, it sends an ASCII Ack character, which
tells the host it is ready for more data.
"Classic" HP 3000 architecture uses this form of pacing. MPE\iX systems do not; the Enq/Ack setting is disregarded in this environment.
This setting reflects the current terminal state of HP Enq/Ack, which can be changed by the host. The associated default setting, saved with the model, is HP Enq/Ack Default.