The latest way to make copies of the seismic data in real-time: 
diagram 1 and diagram 2.
Watch stander's instructions for tape copy and brute stack.
The data flow and computer interconnectivity are diagrammed here.

Paul's watch notes and navigation are here.

The Syntron 3490E SEG-D tapes were reformatted to SEG-Y and written
to two DLT tapes on computer Heezen.  The tape copy script(s) is also
a record of the changing streamer geometry.  The script(s) also
apply the streamer geometery and created rp numbers (SEG-Y trace
header word 6).  The type of geometry applied changed in mid-cruise
from the user having to give the shot spacing (dfls or
distance-from-last-shot) to automatically determining the
each shot's location fron the real-time GPS.  An explanation of 
sioseis' rp number calculation is given here.

Sonobuoys were recorded in Syntron channel set 2, trace 1.  Channel
set 2 was excluded in the tape copy script.  The get_sonobuoy script
collects all the trace 1s of channel set 2 in real-time and writes
them to disk.

A real-time brute stack plot was done on grampus.  This script
used several newish features: Reading the pseudo-SEG-D data in
real-time from "Seisnet"; application of a constant avenor gain (new
avenor parameter HOLD) rather than agc or gains, and type 9 geometry
(dfls for each shot computed from the real-time lat/long).  Process
SEGDDIN also creates and writes some shot information to a log file.
Only the closest 3km (traces 241-480) were used and a velocity
function that varied with the water depth.

Before starting the stack script, for each line, sioseis needs to be
told where the seisnet files are.  The init_seisnet script assumes
the seisnet PC computer writes to grampus' disk 
/export/home3/seisnet/0210/data/$DIR, where $DIR is the line-name
entered into the seisnet computer and is the argument to this script.

Real-time qc plots from Seisnet were done with this script.
This script has the seisnet-sioseis interface built in.  The plot
job should run in a different directory from all other sioseis jobs.

Constant velocity stack script prior to sioplt picking.

Velocity spectra script using Matlab.