This module implements SIK2, SOK2, and CCK2 as described above, given GTT and GTTHALT, with the following differences:
Set echo mask is ignored; the echo mask is always X'F7'.
Set tab stops is not supported.
SIK2 does not pass on gobblers or breaks
No TCEMK is provided
Destroy operation not implemented
While output is in progress, SIK2 will not supply input until the output stops.
There is a timing hazard in the implementation that could, under very unusual circumstances, cause SIK2SIM to misbehave. Fixing it would probably require changing the specs of GTT and/or GTTHALT.